JP5121853B2 - Chemical substance concentration method - Google Patents

Description

  The present invention relates to a chemical substance concentration method for efficiently concentrating various chemical substances contained in a sample gas.

  In recent years, the introduction of atmospheric pressure ionization (API) has enabled ultra-trace analysis. There are two main types of atmospheric pressure ionization.

  One is the electrospray method (ESI). In the electrospray method, first, a sample solution is introduced into a capillary to which a high voltage of several kV is applied. A sample solution is sprayed from the tip of the capillary by flowing nebulizer gas outside the capillary. At this time, the sample solution becomes a large number of charged droplets. The sprayed charged droplets repeat solvent evaporation and splitting. As a result, sample ions are released into the gas phase, and in many cases the sample ions are mass analyzed.

  The other is atmospheric pressure chemical ionization (APCI). In the atmospheric pressure chemical ionization method, a sample solution is first sprayed with a nebulizer gas in a heater. The solvent and sample molecules are then vaporized. Next, the sample molecules are ionized by corona discharge to become reactive ions. Proton exchange occurs between the reaction ion and the sample molecule, and the sample molecule is ionized by proton addition or proton desorption.

  For example, as a mass spectrometer using the atmospheric pressure ionization method, there is a mass spectrometer (APIMS) (Patent Document 1). FIG. 19 shows an atmospheric pressure ionization mass spectrometer disclosed in Patent Document 1.

Is introduced into the ion generating section 15 is the primary ion generation Ar gas 1, primary ion free of NO _x in the needle electrode 19 is ionized is generated. The primary ions are introduced into the mixing unit 30 together with the primary ion generating gas and mixed with the dry air as the sample gas 2. In the mixing unit 30, the dry air is ionized by an ion-molecule reaction caused by primary ions. The ionized sample gas 2 is introduced into the mass analyzer 11 and analyzed. By APIMS10, it analyzes the NO _x contained in the air and exhalation.

  Conventional atmospheric pressure ionization methods require a nebulizer gas and a primary ion generating gas. For this reason, the atmospheric pressure ionizer becomes large and the operation is complicated. Therefore, in order to make the atmospheric pressure ionization apparatus small and simplify the operation, a method of ionizing sample molecules at atmospheric pressure without using a nebulizer gas or a primary ion generating gas has been devised (Patent Document 2, Patent). Reference 3).

  Patent Document 2 discloses an atmospheric pressure ionization apparatus that does not use a nebulizer gas and a primary ion generating gas. This device vaporizes the solvent in the mist by electrostatically spraying a nonvolatile dilute biomolecule solution. Patent Document 2 discloses that this method can be used as a means for micro-concentration of a diluted biomolecule solution by depositing biomolecules on a substrate by electrostatic spraying.

  Furthermore, Patent Document 3 discloses an atmospheric pressure ionizer that does not use a nebulizer gas and a primary ion generating gas. A discharge electrode, a counter electrode positioned opposite the discharge electrode, and a supply means for supplying water to the discharge electrode are held by the discharge electrode by applying a high voltage between the discharge electrode and the counter electrode. In the electrostatic atomizer for atomizing water, the water supply means is water generation means for generating water at the discharge electrode portion based on the moisture in the air.

Japanese Patent Laid-Open No. 11-273615 (page 8, FIG. 1) JP-T-2002-511792 (page 78, FIG. 9) Japanese Patent Laying-Open No. 2005-296753 (page 10, FIG. 1)

  Both of the conventional apparatuses described in Patent Document 2 and Patent Document 3 are excellent as an atmospheric pressure ionization apparatus that does not use a nebulizer gas and a primary ion generating gas. However, when a conventional apparatus is applied to the concentration of a chemical substance in a sample gas, a sufficient concentration efficiency may not be obtained depending on the chemical substance. In particular, the phenomenon is remarkable in volatile chemical substances.

  The present invention solves the above-described problems of the prior art and provides a method for concentrating chemical substances in a sample gas simply and efficiently by electrostatic spraying without using a nebulizer gas and a primary ion generating gas. .

  The present invention for solving the conventional problems is a chemical substance concentration method using an electrostatic spraying device, the electrostatic spraying device comprising a container, a sample gas inlet communicating with the container, and the container A cooling part provided at one end of the cooling part, an atomizing electrode part provided at one end of the cooling part, a counter electrode part provided inside the container, and a chemical substance recovery provided at the other end of the container And a dopant supply port communicating with the container, the sample gas includes water vapor and a chemical substance, and the chemical substance is a substance that forms a condensate together with the water vapor at a dew point temperature of the water vapor or lower. The dopant is a substance that dissolves in the condensate, and the electric affinity of the dopant is larger than the electron affinity of water, and the method includes an injection step of injecting the sample gas from the injection port into the container. ,Previous A first condensate generating step of cooling the atomizing electrode unit by a cooling unit to convert the sample gas into a first condensate on the outer peripheral surface of the atomizing electrode unit; and supplying the dopant from the supply port to the container A supplying step for supplying, a dopant cooling step for cooling the dopant on the outer peripheral surface of the atomizing electrode portion, a dissolving step for dissolving the dopant in the first condensate, and making the first condensate into charged fine particles. It includes a charged fine particle forming step and a recovery step of recovering the charged fine particle to the chemical substance recovery unit.

  In the present invention, the dopant is preferably a polar organic compound.

  In the present invention, the dopant is preferably an organic acid.

  In the present invention, the dopant is preferably acetic acid.

  In the present invention, the dopant is preferably oxygen.

  In the present invention, the concentration of the dopant in the first condensate is preferably higher than the concentration of the chemical substance in the first condensate.

  In the present invention, the container is preferably provided with a barrier at a position where the sample gas collides.

  In the present invention, the sample gas preferably contains a polar organic solvent.

  In the present invention, the chemical substance is preferably a polar organic compound.

  In the present invention, the chemical substance is preferably a volatile organic compound.

  In the present invention, the charged fine particles are preferably heated by infrared light.

  In the present invention, the container preferably includes an optical waveguide.

  In this invention, it is preferable to provide a chemical substance detection part in the said electrostatic spraying apparatus.

  The above object, other objects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

  According to the chemical substance concentration method of the present invention, the nebulizer gas and the primary ion generating gas that are indispensable in the conventional atmospheric pressure ionization method become unnecessary. This is because the sample gas is condensed on the outer peripheral surface of the cooled atomizing electrode portion, and the condensed liquid is electrostatically sprayed. This is because the sample gas is secondary ionized by mixing the primary ions and the sample gas using the sprayed charged fine particles as primary ions.

  Moreover, since both the primary ions and the secondary ions are recovered to the chemical substance recovery unit, the chemical substances can be efficiently concentrated. Further, since the dopant is mixed into the sample gas, the generation of charged fine particles is promoted. As a result, chemical substances can be concentrated efficiently. Therefore, according to the chemical substance concentration method of the present invention, a chemical substance can be concentrated easily and efficiently using an electrostatic spraying device.

FIG. 1 is a schematic diagram of the electrostatic spraying apparatus of the first embodiment. FIG. 2A is an explanatory diagram showing an injection process in the electrostatic spraying device of the first embodiment, and FIG. 2B shows a first condensate production process in the electrostatic spraying device of the first embodiment. It is explanatory drawing shown. FIG. 3A is an explanatory diagram showing a supply process in the electrostatic spraying device of the first embodiment, and FIG. 3B is an explanatory diagram showing a dopant cooling process in the electrostatic spraying device of the first embodiment. It is. FIG. 4A is an explanatory view showing a dissolving step in the electrostatic spraying apparatus of the first embodiment, and FIG. 4B is an explanation showing a charged fine particle forming process in the electrostatic spraying apparatus of the first embodiment. FIG. FIG. 5 is an explanatory diagram showing a recovery process in the electrostatic spraying apparatus of the first embodiment. FIG. 6 is a schematic diagram of the electrostatic spraying apparatus of the second embodiment. Fig.7 (a) is explanatory drawing which shows the injection | pouring process in the electrostatic spraying apparatus of Embodiment 2, FIG.7 (b) shows the 1st condensate production | generation process in the electrostatic spraying apparatus of Embodiment 2. FIG. It is explanatory drawing shown. FIG. 8A is an explanatory diagram showing a supply process in the electrostatic spraying device of the second embodiment, and FIG. 8B is an explanatory diagram showing a dopant cooling process in the electrostatic spraying device of the second embodiment. It is. FIG. 9A is an explanatory view showing a dissolving step in the electrostatic spraying device of the second embodiment, and FIG. 9B shows a first charged particle forming step in the electrostatic spraying device of the second embodiment. It is explanatory drawing shown. FIG. 10A is an explanatory view showing a second charged fine particle forming step in the electrostatic spraying device of the second embodiment, and FIG. 10B shows a recovery step in the electrostatic spraying device of the second embodiment. It is explanatory drawing shown. FIG. 11 is a schematic diagram of the electrostatic spraying device of the third embodiment. FIG. 12 is a schematic diagram of the electrostatic spraying device of the fourth embodiment. FIG. 13 is a microscope photograph of a state in which the first condensate is formed on the outer peripheral surface of the atomizing electrode part in Example 1. FIG. 14A is a microscope photograph obtained by photographing the tailor cone formed at the tip of the atomizing electrode portion in Example 1, and FIG. 14B is a trace of the microscope photograph of FIG. FIG. FIG. 15 is a microscope photograph of the outer peripheral surface of the chemical substance recovery unit in Example 1. FIG. 16 is a diagram showing the analysis result of the collected liquid of Example 1. FIG. 17 is an enlarged view of a part of FIG. FIG. 18 is a diagram showing the analysis result of the collected liquid of Example 2. FIG. 19 is a schematic diagram of a conventional atmospheric pressure ionization mass spectrometer.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate.

(Embodiment 1)
FIG. 1 is a schematic diagram of the electrostatic spraying apparatus of the first embodiment.

  In this embodiment, the method of electrostatic spraying of the sample gas is performed in substantially the same manner as the method described in Japanese Patent Application Nos. 2008-024667 and 2007-279875 filed by the same inventors as the present application.

  The most different point from the method described in Japanese Patent Application Nos. 2008-024667 and 2007-279875 is that a dopant is added to the condensate.

  The dopant is added in order to promote the formation of charged fine particles in the condensate. The sample gas can be efficiently concentrated by adding the dopant. The electron affinity of the dopant is greater than the electron affinity of water. The electron affinity mentioned here is the energy released when an electron is added to a neutral atom or neutral molecule. Therefore, the dopant is easier to obtain electrons than water. As a result, the condensate containing the dopant is easily made into charged fine particles.

  Below, the electrostatic spray apparatus 100 which has a mechanism which adds a dopant to a condensed liquid is demonstrated. Details of the electrostatic spraying apparatus 100 are described in Japanese Patent Application Nos. 2008-024667 and 2007-279875.

  The container 101 is partitioned from the outside by a partition wall. No material enters or exits through the bulkhead. The shape of the container 101 may be a rectangular parallelepiped, or may be a polyhedron, a spindle shape, a spherical shape, or a flow path shape. It is preferable that the sample gas does not stay in a part of the container 101. The volume of the container 101 is preferably 10 pL or more and 100 mL or less. The volume of the container 101 is more preferably 1 mL or more and 30 mL or less.

  The material of the container 101 is preferably a material with little adsorbed gas or built-in gas. Most preferably, the material of the container 101 is a metal. The metal is preferably stainless steel, but may be aluminum, brass, brass or the like.

  The material of the container 101 may be an inorganic material. The material of the container 101 may be glass, silicon, alumina, sapphire, quartz glass, borosilicate glass, silicon nitride, alumina, silicon carbide, or the like. The material of the container 101 may be a silicon substrate coated with silicon dioxide, silicon nitride, or tantalum oxide.

  The material of the container 101 may be an organic material. The material of the container 101 may be acrylic, polyethylene terephthalate, polypropylene, polyester, polycarbonate, fluororesin, polydimethylsiloxane, PEEK (registered trademark), Teflon (registered trademark), or the like. When an organic material is used as the material of the container 101, it is more preferable to coat the outer peripheral surface of the container 101 with a metal thin film. The metal thin film is preferably a material having excellent gas barrier properties.

  The material of the container 101 may be one of the above materials or a combination of a plurality of types.

  The container 101 is preferably rigid, but may be flexible such as an air bag, a balloon, a flexible tube, or a syringe.

  The inlet 102 is provided so as to communicate with the container 101. The inlet 102 is used to inject a sample gas into the container 101. The inlet 102 is preferably provided at a position where the sample gas can be quickly injected into the container 101 or at a position where the sample gas can be uniformly injected into the container 101.

  The injection port 102 preferably has a shape that allows the sample gas to be uniformly injected into the container 101. The inlet 102 may have a number of holes such as an air shower. In the present invention, the size and material of the inlet 102 are not limited. The shape of the inlet 102 may be a straight tube as shown in FIG. 1, or a branch may be provided in the middle. Moreover, the injection port 102 may be one place or a plurality of places.

  The discharge port 103 is provided at the other end of the container 101. The discharge port 103 is used for discharging excess sample gas out of the sample gas filling the container 101. The discharge port 103 is preferably provided at a position where the sample gas filling the container 101 is quickly discharged. In the present invention, the shape, size, and material of the discharge port 103 are not limited. The shape of the discharge port 103 may be a straight tube as shown in FIG. 1 or may be provided with a branch in the middle. Further, the discharge port 103 may be one place or a plurality of places.

  The cooling unit 104 is provided at one end of the container 101. The cooling unit 104 can cool the sample gas to a temperature equal to or lower than the dew point temperature of water vapor. The cooling unit 104 is most preferably a thermoelectric element, but may be a heat pipe using a refrigerant, an air heat exchange element, or a cooling fan. The area of the cooling unit 104 is preferably small because the electrode can be cooled. Moreover, it is preferable that the area of the cooling unit 104 is small from the viewpoint of reducing power consumption.

  In order to efficiently cool the electrode, it is preferable to provide an uneven structure on the surface of the cooling unit 104. A porous body may be provided on the surface of the cooling unit 104. The position of the cooling unit 104 is most preferably the bottom of the container 101, but it may be a side or a ceiling, or a plurality of cooling units 104 may be provided by combining them.

In order to suppress heat conduction, the contact area between the cooling unit 104 and the container 101 is preferably small, and specifically, it is preferably 100 μm ² or more and 5 mm ² or less.

  The atomizing electrode unit 105 is provided at one end of the cooling unit 104. The atomizing electrode unit 105 is cooled by the cooling unit 104 to a temperature equal to or lower than the dew point temperature of water vapor. The atomizing electrode unit 105 is preferably in direct contact with the cooling unit 104, but may be in contact with a material having a high thermal conductivity. A material having a high thermal conductivity is preferably a thermal conductive sheet, a thermal conductive resin, a metal plate, grease, a metal paste, or the like.

  The atomizing electrode portion 105 is most preferably on the bottom surface of the container 101, but may be on the side surface, ceiling, or bottom center portion of the container 101. Further, the atomizing electrode portion 105 may be separated from the side surface of the container 101 by 10 mm or more. It is preferable that the tip of the atomizing electrode portion 105 is facing upward.

  The shape of the atomizing electrode portion 105 is preferably a needle shape. The length of the needle is preferably 3 mm or more and 10 mm or less. The atomizing electrode portion 105 may be solid, hollow, or porous. An uneven structure or a groove structure may be provided on the surface of the atomizing electrode portion 105. A spherical protrusion may be provided at the tip of the atomizing electrode portion 105. The entire atomizing electrode portion 105 is preferably cooled to a dew point temperature of water vapor or lower.

  The material of the atomizing electrode portion 105 is preferably a good heat conductive material, and most preferably a metal. The metal may be a single metal such as copper, aluminum, nickel, tungsten, molybdenum, titanium, or tantalum, and an alloy or intermetallic compound in which two or more single metals are combined, such as stainless steel, copper tungsten, brass, brass, etc. , High speed steel, carbide, etc.

The material of the atomizing electrode portion 105 may be an inorganic material, a semiconductor, or a carbon material. For example, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, SiC, carbon nanotube, graphene, graphite, or the like can be used. The material of the atomizing electrode portion 105 may be one type of the above materials or a combination of a plurality of types.

In order to suppress wear of the atomizing electrode part 105, it is preferable to cover the surface of the atomizing electrode part 105. In order to facilitate transfer of electrons between the surface of the atomizing electrode part 105 and the condensate, it is preferable to cover the surface of the atomizing electrode part 105. The material for covering the atomizing electrode portion 105 is preferably a metal, a semiconductor, an inorganic material, or the like. As a material for covering the atomizing electrode part 105, gold, platinum, aluminum, nickel, chromium, semiconductor, carbon material, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, SiC, carbon nanotube, graphene, graphite Etc. can be used. The material for covering the atomizing electrode portion 105 may be a single layer of the above material, or a plurality of types may be laminated.

  There may be one atomizing electrode portion 105 or a plurality of atomizing electrode portions 105. When a plurality of atomizing electrode portions 105 are provided, they may be arranged one-dimensionally such as in a straight line shape, a circular shape, a parabolic shape, an elliptical shape, a square lattice shape, an oblique lattice shape, They may be arranged two-dimensionally such as a close-packed lattice, radial, random, or three-dimensionally, such as spherical, parabolic, elliptical.

  The surface of the atomizing electrode portion 105 is preferably hydrophilic, but may be water repellent.

  The counter electrode unit 106 is provided inside the container 101. A high voltage is applied between the counter electrode unit 106 and the atomizing electrode unit 105, and the condensate is sprayed. The shape of the counter electrode portion 106 is most preferably an annular shape. When the counter electrode part 106 is annular, the outer diameter of the counter electrode part 106 is 10 mm or more and 30 mm or less, the inner diameter of the counter electrode part 106 is 1 mm or more and 9.8 mm or less, and the thickness of the counter electrode part 106 is 0.1 mm or more. It is preferable that it is 5 mm or less. The shape of the counter electrode 106 may be a polygon such as a rectangle or a trapezoid.

  The shape of the counter electrode portion 106 is preferably a flat surface, but may be a hemispherical surface or a dome shape. The counter electrode portion 106 is preferably formed with a slit or a through hole through which a chemical substance passes. In the present invention, the shape of the counter electrode portion 106 is not limited to the above.

  The distance between the counter electrode portion 106 and the atomizing electrode portion 105 is preferably 3 mm or more and 10 mm or less. The counter electrode unit 106 may be movable with respect to the container 101. In the case where the counter electrode unit 106 is annular, it is preferable to provide the atomizing electrode unit 105 on a straight line that passes through the center of the counter electrode unit 106 and perpendicularly intersects the plane of the counter electrode unit 106.

  The counter electrode portion 106 is preferably electrically insulated from the container 101.

  The material of the counter electrode portion 106 is preferably a conductor, and most preferably a metal. The metal is preferably a single metal such as copper, aluminum, nickel, tungsten, molybdenum, titanium, and tantalum, but an alloy or intermetallic compound in which two or more single metals are combined, such as stainless steel, copper tungsten, brass, Brass, high speed steel, carbide, etc. may be used.

The material of the counter electrode portion 106 may be an inorganic material, and may be a semiconductor, a carbon material, or an insulator. For example, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, SiC, carbon nanotube, graphene, graphite, alumina, sapphire, silicon oxide, ceramics, glass, polymer, and the like can be used. The material of the counter electrode unit 106 may be one of the above materials or a combination of a plurality of types.

  The material of the counter electrode portion 106 is preferably a good heat conductor. It is preferable to heat the counter electrode unit 106 so that unnecessary condensate does not adhere to the surface of the counter electrode unit 106. The counter electrode part 106 is preferably heated to a temperature equal to or higher than the dew point temperature of water vapor.

In order to suppress wear of the counter electrode unit 106, it is preferable to cover the surface of the counter electrode unit 106. The material covering the counter electrode portion 106 is preferably a metal, a semiconductor, an inorganic material, or the like. As a material for covering the counter electrode portion 106, gold, platinum, aluminum, nickel, chromium, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, carbon nanotube, graphene, graphite, or the like can be used. The material for covering the counter electrode portion 106 may be a single layer of the above material, or a plurality of types may be laminated.

  The surface of the counter electrode portion 106 is preferably hydrophilic, but may be water repellent.

  There may be one counter electrode unit 106 or a plurality of counter electrode units 106. When a plurality of the counter electrode portions 106 are provided, they may be arranged one-dimensionally, such as a straight line, a circular shape, a parabolic shape, an elliptical shape, a square lattice shape, an oblique lattice shape, They may be arranged two-dimensionally, such as closely packed grid, radial, random, or three-dimensionally, such as spherical, parabolic, elliptical.

  The chemical substance recovery unit 107 is provided at the other end of the container 101. The chemical substance recovery unit 107 is used to recover the chemical substance sprayed electrostatically. The chemical substance recovery unit 107 is preferably cooled to a temperature equal to or lower than the dew point of water vapor by the second cooling unit 108. The chemical substance recovery unit 107 is preferably in direct contact with the second cooling unit 108, but may be in contact with a material having a high thermal conductivity. A material having a high thermal conductivity is preferably a thermal conductive sheet, a thermal conductive resin, a metal plate, grease, a metal paste, or the like.

  The chemical substance recovery unit 107 is most preferably on the ceiling of the container 101, but may be on the side surface, bottom surface, or center of the ceiling of the container 101. Further, the chemical substance recovery unit 107 may be separated from the side surface of the container 101 by 10 mm or more. It is preferable that the tip of the chemical substance recovery unit 107 faces downward.

  It is preferable that the chemical substance recovery unit 107 has a needle shape. The length of the needle is preferably 3 mm or more and 10 mm or less. The shape of the chemical substance recovery unit 107 may be solid, hollow, or porous. An uneven structure or a groove structure may be provided on the surface of the chemical substance recovery unit 107. A spherical protrusion may be provided at the tip of the chemical substance recovery unit 107. The entire chemical substance recovery unit 107 is preferably cooled below the dew point temperature of water vapor.

  The material of the chemical substance recovery unit 107 is preferably a good heat conductive material, and most preferably a metal. The metal is preferably a single metal such as copper, aluminum, nickel, tungsten, molybdenum, titanium, or tantalum, but may be an alloy or an intermetallic compound in which two or more single metals are combined. For example, stainless steel, copper tungsten, brass, brass, high speed steel, carbide or the like may be used.

The material of the chemical substance recovery unit 107 may be an inorganic material, a semiconductor, or a carbon material. For example, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, SiC, carbon nanotube, graphene, graphite, or the like can be used. The material of the chemical substance recovery unit 107 may be one of the above materials or a combination of a plurality of types.

In order to suppress wear of the chemical substance recovery unit 107, it is preferable to cover the surface of the chemical substance recovery unit 107. In order to facilitate transfer of electrons between the surface of the chemical substance recovery unit 107 and the condensate, it is preferable to cover the surface of the chemical substance recovery unit 107. The material covering the chemical substance recovery unit 107 is preferably a metal, a semiconductor, an inorganic material, a carbon material, or the like. Gold, platinum, aluminum, nickel, chromium, LaB ₆ , SiC, WC, silicon, gallium arsenide, gallium nitride, carbon nanotube, graphene, graphite, or the like can be used as a material for covering the chemical substance recovery unit 107. The material covering the chemical substance recovery unit 107 may be a single layer of the above material or a plurality of types may be laminated.

  There may be one chemical substance recovery unit 107 or a plurality of chemical substance recovery parts 107. When a plurality of chemical substance recovery units 107 are provided, they may be arranged one-dimensionally such as in a straight line shape, a circular shape, a parabolic shape, an elliptical shape, a square lattice shape, an oblique lattice shape, They may be arranged two-dimensionally, such as a close-packed grid, a radial pattern, or a random pattern. Further, they may be arranged three-dimensionally such as a spherical shape, a parabolic curved surface shape, an elliptical curved surface shape or the like.

  The surface of the chemical substance recovery unit 107 is preferably hydrophilic, but may be water repellent.

  The second cooling unit 108 is preferably provided at one end of the chemical substance recovery unit 107. The second cooling unit 108 can cool to the dew point temperature or lower of the water vapor contained in the sample gas. The second cooling unit 108 is most preferably a thermoelectric element, but may be a heat pipe using a refrigerant, an air heat exchange element, or a cooling fan. Since the electrode only needs to be cooled, the area of the second cooling unit 108 is preferably small. Also from the viewpoint of reducing power consumption, the area of the second cooling unit 108 is preferably small.

  In order to efficiently cool the electrode, an uneven structure or a porous body may be provided on the surface of the second cooling unit 108. The position of the second cooling part 108 is most preferably the ceiling part of the container 101, but it may be a side part or a bottom part, or a plurality of second cooling parts 108 may be provided in combination.

In order to suppress heat conduction, the contact area between the second cooling unit 108 and the container 101 is preferably small, and specifically, it is preferably 100 μm ² or more and 5 mm ² or less.

  The container 101 is provided with a dopant supply port 109. In FIG. 1, the supply port 109 is provided so as to communicate with the injection port 102. The supply port 109 is preferably provided at a position where the dopant can be quickly mixed with the sample gas, or at a position where the dopant can be uniformly mixed with the sample gas.

  In the present invention, the size and material of the supply port 109 are not limited, but the supply port 109 preferably has a shape that allows the dopant to be uniformly injected into the sample gas. The supply port 109 may have a number of holes such as an air shower. The shape of the supply port 109 may be a straight tube as shown in FIG. 1, or a branch may be provided in the middle. The supply port 109 may be one place or a plurality of places.

  A valve 110 is provided at the supply port 109. The valve 110 is used to control the dopant injection amount, the injection speed, and the like. The valve 110 may be a gate valve, a ball valve, a check valve, a stop valve, a diaphragm valve, a needle valve, or the like.

  A mixer 111 is provided at the supply port 109. The mixer 111 is used to mix the dopant into the sample gas. The mixer 111 may be a static mixer such as a stator tube mixer, a spiral mixer, or a diffuser, or may be an active mixer such as a rotary mixer or a high-frequency mixer.

  In the present invention, the material, position, and type of the valves 112a and 112b are not limited, but the inlet 112 and the outlet 103 are preferably provided with the valve 112a and the valve 112b, respectively. It is preferable that the container 101 can be closed by the valves 112a and 112b. If the conductance of the inlet 102 and the outlet 103 is small, the effect similar to that of the container 101 being closed can be obtained. In this case, the valves 112a and 112b need not be used.

  The valves 112a and 112b may be valves that control the flow of the sample gas. The valves 112a and 112b may be check valves or stop valves.

  2-5 is explanatory drawing which shows operation | movement of the electrostatic spraying apparatus in Embodiment 1 of this invention. 2 to 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

<Injection process>
In the injection step, a sample gas 203 containing water vapor 201 and a chemical substance 202 is injected into the container 101 through the injection port 103. FIG. 2 (a) shows the injection process. In FIG. 2 (a), only two types of chemical substances 202, namely the chemical substances 202a and 202b, are shown, but there may be one type or three or more types. The relative humidity of the sample gas 203 is preferably 50% or more and 100% or less, and more preferably 80% or more and 100% or less. In the injection step, water vapor 201 may be newly added to the sample gas 203. In the present invention, the type and concentration of the chemical substance 202 are not limited, but the sample gas 203 preferably contains a polar organic solvent such as acetonitrile, isopropanol, formic acid, and acetic acid.

  The sample gas 203 may collide with the inner wall of the container 101, the counter electrode unit 106, or the chemical substance recovery unit 107.

  It is preferable to inject the sample gas 203 into the container 101 at a large flow rate. The injection speed of the sample gas 203 is preferably 10 sccm or more and 1000 sccm or less, and more preferably 100 sccm or more and 500 sccm or less. The injection speed of the sample gas 203 is preferably constant, but the injection speed may vary. In addition, sccm here means standard cc / min.

  Preferably, 10 mL or more and 3000 mL or less of the sample gas 203 is injected into the container 101, and more preferably 100 mL or more and 1000 mL or less of the sample gas 203 is injected.

  A room temperature sample gas 203 may be injected into the container 101, or a heated sample gas 203 may be injected. The temperature of the sample gas 203 is preferably 20 ° C. or higher and 100 ° C. or lower, and more preferably 25 ° C. or higher and 40 ° C. or lower.

  The sample gas 203 may be injected by pressurizing the inlet 102 side, or the sample gas 203 may be injected by reducing the pressure on the outlet 103 side.

  Although it is preferable to open the valves 112a and 112b, the inflow amount of the sample gas 203 may be adjusted by opening and closing the valves 112a and 112b as appropriate.

  Before injecting the sample gas 203 into the container 101, it is preferable to fill the inside of the container 101 with clean air, dry nitrogen, an inert gas, a standard gas having a relative humidity similar to that of the sample gas 203 or a calibration gas. .

  Excess sample gas 203 is preferably discharged from the discharge port 103.

  The pressure inside the container 101 is most preferably atmospheric pressure, but the container 101 may be depressurized or pressurized. In the present invention, the pressure in the container 101 is not limited.

  In the steps after the injection step, it is preferable to keep the temperature of the container 101, the injection port 102, the discharge port 103, and the counter electrode unit 106 at or above the dew point temperature of water vapor so that the sample gas 203 is not condensed.

<First condensate production step>
Next, in the first condensate generation step, the atomizing electrode unit 105 is cooled to a dew point temperature of the water vapor 201 or lower by the cooling unit 104. A first condensate 204 containing water vapor 201 and chemical substance 202 is formed on the outer peripheral surface of the atomizing electrode portion 105. FIG. 2B shows the first condensate production step. In the initial stage of the first condensate production step, the first condensate 204 is in the form of droplets on the outer peripheral surface of the atomizing electrode portion 105. In the progress stage of the first condensate generation process, the outer peripheral surface of the atomizing electrode part 105 is covered with the first condensate 204.

  It is preferable to control the temperature of the cooling unit 104 so that the amount of the first condensate 204 does not become excessive. It is preferable that the temperature of the atomization electrode part 105 is equal to or higher than the freezing point of the first condensate 204.

  The temperature of the atomizing electrode part 105 is preferably 0 ° C. or higher and 20 ° C. or lower, and more preferably 0 ° C. or higher and 15 ° C. or lower.

  The sample gas 203 is preferably continuously injected, but the injection of the sample gas 203 may be stopped.

<Supply process>
In the supply step, the dopant 205 is supplied to the container 101. FIG. 3A shows the supply process. The dopant 205 is supplied to the container 101 through the supply port 109. The dopant 205 is supplied to the container 101 through the inlet 102.

  The dopant 205 is a substance that dissolves in the first condensate 204. The electron affinity of the dopant 205 is greater than that of water.

  The dopant 205 is preferably an organic compound, more preferably a polar organic compound, a water-soluble organic compound, or an organic compound that is a biomolecule.

  The dopant 205 is preferably an organic acid. The dopant 205 is more preferably acetic acid, but may be formic acid, citric acid, oxalic acid, or the like.

  The dopant 205 is preferably a lower alcohol, but may be a higher alcohol. As the lower alcohol, ethanol is most preferable, but methanol, 2-propanol, butanol and the like may be used.

  The dopant 205 may be an aliphatic hydrocarbon or an aromatic hydrocarbon. As the dopant 205, acetone, acetaldehyde, chloroform, carbon tetrachloride, butadiene, tetracyanoethylene, formaldehyde, azulene, acetophenone, anisole, aniline, 9,10-anthraquinone, o-xylene, chlorobenzene, 1,2,3,5 -Tetramethylbenzene, triphenylene, toluene, naphthalene, biphenyl, pyrene, phenol, fluorobenzene, hexamethylbenzene, benzene, benzoquinone, pentacene, phthalic anhydride, etc. can be used.

  The dopant 205 may be an aromatic molecule such as esters, ketones, sesquiterpenes, terpenes, aromatic aldehydes, monoterpenes, and lactones. The dopant 205 is preferably methyl salicylate, menthol, or sclareol, but linalyl acetate, limonene, linalool, and the like can also be used.

  The dopant 205 may be a volatile organic compound, and the molecular weight is preferably 16 or more and 300 or less.

  The dopant 205 may be oxygen, nitrogen dioxide, nitric oxide or carbon dioxide.

  The concentration of the dopant 205 in the sample gas 203 is preferably 0.03% or more and 3% or less, and more preferably 0.3% or more and 1% or less.

  The temperature of the dopant 205 is preferably 20 ° C. or higher and 100 ° C. or lower, and more preferably 25 ° C. or higher and 40 ° C. or lower. The temperature of the dopant 205 is most preferably the same as the temperature of the sample gas 203, but may be lower or higher than the temperature of the sample gas 203.

  The supply rate of the dopant 205 is preferably 0.01 sccm or more and 1000 sccm or less, and more preferably 0.1 sccm or more and 5 sccm or less. The implantation rate of the dopant 205 is preferably constant, but the implantation rate may vary.

<Dopant cooling step>
In the dopant cooling step, the dopant 205 is cooled on the outer peripheral surface of the atomizing electrode portion 105. FIG. 3B shows a dopant cooling step. The dopant 205 is preferably cooled by the atomizing electrode unit 105, but may be cooled by a cooler. The temperature of the dopant 205 is preferably 0 ° C. or higher and 20 ° C. or lower, and the temperature is more preferably 0 ° C. or higher and 15 ° C. or lower. The dopant 205 is preferably cooled simultaneously with the sample gas 203.

<Dissolution process>
In the dissolving step, the dopant 205 is dissolved in the first condensate 204. FIG. 4A shows the dissolution process. It is preferable that the cooled dopant 205 is dissolved in the first condensate 204. The dopant 205 is preferably water-soluble. The concentration of the dopant 205 in the first condensate 204 is preferably higher than the concentration of the chemical substance 202 in the first condensate 204. The concentration of the dopant 205 in the first condensate 204 is preferably 0.1 ppm or more and 3% or less.

  In the dissolving step, it is preferable to uniformly dissolve the dopant 205 in the first condensate 204, but the dopant 205 may be mixed into the first condensate 204. It is preferable that the first condensate 204 moves on the outer peripheral surface of the atomizing electrode unit 105. The surface area of the first condensate 204 is preferably large so that the dopant 205 can be easily dissolved in the first condensate 204. The first condensate 204 is preferably in the form of droplets or a water film.

<Charged fine particle process>
Next, in the charged fine particle forming step, a large number of first charged fine particles 206 are formed from the first condensate 204. FIG. 4B shows a charged fine particle forming step. The first charged fine particle 206 may be a cluster composed of one molecule to several tens of molecules, a fine particle composed of several tens to several hundred molecules, or a droplet composed of several hundred or more. There may be. Or these two or more types may be mixed.

  The first charged fine particles 206 may contain electrically neutral molecules, ions or radicals derived from the sample gas 203, or the like.

  The first charged fine particles 206 are preferably negatively charged. When the first charged fine particles 206 are negatively charged, it is preferable that the electron affinity of the chemical substance 202 is greater than the electron affinity of water. The electron affinity of the dopant 205 is preferably larger than that of water and the chemical substance 202.

  The first charged fine particles 206 may be positively charged. When the first charged fine particles 206 are positively charged, the ionization energy of the chemical substance 202 is preferably smaller than the ionization energy of water. The ionization energy of the dopant 205 is preferably smaller than the ionization energy of water and the chemical substance 202.

  The method of turning the first condensate 204 into charged fine particles is most preferably electrostatic spraying. The principle of electrostatic spraying is as follows. The first condensate 204 is conveyed to the tip of the atomization electrode unit 105 by a voltage applied between the atomization electrode unit 105 and the counter electrode unit 106. The liquid level of the first condensate 204 rises in a conical shape toward the counter electrode 106 due to the Coulomb attractive force. When condensation further proceeds on the outer peripheral surface of the atomizing electrode portion 105, a conical first condensate 204 grows. Thereafter, the electric charge concentrates on the tip of the first condensate 204 and the Coulomb force increases. When the Coulomb force exceeds the surface tension of water, the first condensate 204 is split and scattered to form the first charged fine particles 206.

  From the viewpoint of the stability of the first charged fine particles 206, the diameter of the first charged fine particles 206 is preferably 1 nm or more and 30 nm or less.

The charge amount added to the first charged fine particles 206 is preferably the same amount or more and 10 times or less as the elementary charge amount (1.6 × 10 ⁻¹⁹ C) per fine particle.

  The ratio of the chemical substance 202 to the water vapor 201 in the first charged fine particles 206 is preferably higher than the ratio of the chemical substance 202 to the water vapor 201 in the sample gas 203. The ratio of the chemical substance 202 to the water vapor 201 in the first charged fine particles 206 may change before going to the chemical substance recovery unit 107, but it is preferable that the ratio becomes higher before going to the chemical substance recovery part 107.

  Most preferably, a DC voltage is applied between the atomizing electrode part 105 and the counter electrode part 106, that is, a potential difference is provided between the atomizing electrode part 105 and the counter electrode part 106. A voltage that does not generate corona discharge is preferably applied between the atomizing electrode portion 105 and the counter electrode portion 106, and specifically, a DC voltage of 4 kV to 6 kV is preferably applied.

  In the charged fine particle forming step, it is most preferable to apply a negative voltage to the atomizing electrode unit 105 with respect to the counter electrode unit 106, but a positive voltage may be applied. The counter electrode portion 106 is most preferably a GND electrode. In the charged fine particle forming step, an AC voltage may be applied between the atomizing electrode unit 105 and the counter electrode unit 106. Further, a pulse voltage may be applied between the atomizing electrode unit 105 and the counter electrode unit 106.

  The DC voltage applied between the atomizing electrode unit 105 and the counter electrode unit 106 may be a fixed value or a variable value. The variable value is preferably controlled according to the state of charged fine particles. The state of the charged fine particles may be monitored by monitoring the current value flowing between the atomizing electrode unit 105 and the counter electrode unit 106, or monitoring the current value by providing a dedicated electrode pair.

<Recovery process>
In the recovery step, the first charged fine particles 206 are recovered to the chemical substance recovery unit 107. FIG. 5 shows the recovery process. In the recovery step, the sample gas 203 may be recovered directly to the chemical substance recovery unit 107. It is preferable that the amount of the sample gas 203 recovered directly to the chemical substance recovery unit 107 is small. Moreover, it is preferable to stop an injection | pouring process during a collection | recovery process.

  The first charged fine particles 206 are preferably collected by electromagnetic force or electrostatic force. In the recovery step, it is preferable to apply a DC voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106, that is, to provide a potential difference between the counter electrode unit 106 and the chemical substance recovery unit 107. The DC voltage is preferably from 0.01 kV to 6 kV, and more preferably from 0.01 kV to 0.6 kV.

  When the first charged fine particles 206 have a negative charge, it is preferable to apply a positive voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. On the other hand, when the first charged fine particles 206 have a positive charge, it is preferable to apply a negative voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. The voltage application is preferably continuous, but may be pulsed.

  The counter electrode portion 106 is most preferably a GND electrode. An AC voltage is preferably applied between the chemical substance recovery unit 107 and the counter electrode unit 106, but a pulse voltage may be applied.

  The chemical substance recovery unit 107 is preferably cooled below the dew point temperature of the water vapor 201. The first charged fine particles 206 are preferably used as the recovery liquid 207 on the outer peripheral surface of the chemical substance recovery unit 107. In the initial stage of the recovery process, it is preferable that the recovery liquid 207 is in the form of droplets on the outer peripheral surface of the chemical substance recovery unit 107. In the progress stage of the recovery process, it is preferable that the outer peripheral surface of the chemical substance recovery unit 107 is covered with the recovery liquid 207. The chemical substance recovery unit 107 is preferably needle-shaped, and the recovery liquid 207 is preferably recovered at the tip of the chemical substance recovery unit 107. The outer peripheral surface of the chemical substance recovery unit 107 is preferably hydrophilic, but may be water repellent.

  The chemical substance recovery unit 107 is preferably directed downward. As shown in FIG. 5, it is preferable to collect the recovery liquid 207 at the tip of the chemical substance recovery unit 107 by gravity.

  As shown in FIG. 5, it is also preferable to collect the recovery liquid 207 at the tip of the chemical substance recovery unit 107 by electrostatic force. The tip of the chemical substance recovery unit 107 preferably has a shape in which the electric field concentrates, and most preferably has a needle shape. On the outer peripheral surface of the chemical substance recovery unit 107, the recovery liquid 207 preferably moves to the tip of the chemical substance recovery unit 107 by electrostatic force. The recovered liquid 207 preferably contains a polar organic compound or water.

  The chemical substance recovery unit 107 is preferably neutralized. The neutralization of the chemical substance recovery unit 107 may be performed constantly or appropriately. The neutralization of the chemical substance recovery unit 107 may be performed by grounding or may be performed using an ionizer.

  It is most preferable to cool the chemical substance recovery unit 107 after applying a voltage to the chemical substance recovery part 107 with respect to the counter electrode part 106. The chemical substance recovery unit 107 may be cooled at the same time as a voltage is applied to the chemical substance recovery part 107 with respect to the counter electrode part 106. Further, the sample gas 203 may be directly condensed in the chemical substance recovery unit 107.

  Interfering substances other than the water vapor 201 and the detection target substance contained in the recovered liquid 207 may be removed. In order to remove interfering substances from the recovered liquid 207, a filter or an adsorbent may be used, or other removal methods may be used.

  In the present embodiment, at least two steps from the injection step to the recovery step described above may be performed simultaneously. That is, for example, the injection step and the first condensate generation step may be performed simultaneously. Or you may perform each process in order.

(Embodiment 2)
FIG. 6 is a schematic diagram of an electrostatic spraying apparatus according to Embodiment 2 of the present invention. In FIG. 6, the same components as those in FIG.

  The most different point between the present embodiment and the first embodiment is that the function of the mixer 111 is added to the container 101 itself. That is, the sample gas 203 and the dopant 205 are mixed inside the container 101. For this purpose, the supply port 109 is directly connected to the container 101. In the container 101, the sample gas 203 and the dopant 205 are mixed.

  In the present embodiment, the electrostatic spraying device 100 has the following configuration.

  The container 101 is preferably rigid, but may be flexible such as an air bag, a balloon, a flexible tube, or a syringe. From the viewpoint of maintenance, the container 101 is preferably openable and closable by a hinge 301, but may be openable and closable by other methods.

  A barrier 302 is preferably provided in the vicinity of the supply unit 109 in the container 101 so that the sample gas generates a turbulent flow, a spiral flow, a vortex flow, or the like. It is also preferable to provide a maze inside the container 101 so that the sample gas generates turbulent flow, spiral flow, vortex flow, or the like.

  The inlet 102 is provided so as to communicate with the container 101. The inlet 102 is used to inject a sample gas into the container 101. The inlet 102 is preferably provided at a position where the sample gas can be quickly injected into the container 101 and / or at a position where the sample gas can be uniformly injected into the container 101. The inlet 102 is preferably provided at a position where the sample gas generates a turbulent flow, a spiral flow, a vortex flow, or the like. For example, when the container 101 is a rectangular parallelepiped, the inlet 102 is preferably provided at a corner.

  In the present invention, the size and material of the injection port 102 are not limited, but it is preferable that the sample gas is uniformly injected into the container 101. The inlet 102 may have a number of holes such as an air shower. The direction of the tip of the injection port 102 may be inclined with respect to the wall surface of the container 101 so that the sample gas generates a spiral flow inside the container 101. The venturi effect may be used by narrowing the tip of the inlet 102 so that the sample gas generates a spiral flow. The shape of the inlet 102 may be a straight tube as shown in FIG. 6, or a branch may be provided in the middle. The inlet 102 may be one place or a plurality of places.

  The discharge port 103 is provided at the other end of the container 101. The discharge port 103 is used for discharging excess sample gas out of the sample gas filling the container 101. The discharge port 103 is preferably provided at a position where the sample gas filling the container 101 is quickly discharged. The discharge port 103 may be provided at a position where the sample gas generates a turbulent flow, a spiral flow, a vortex flow, or the like. As shown in FIG. 6, the injection port 102 and the discharge port 103 may be provided at different heights. The inlet 103 and the outlet 104 are preferably provided at the diagonal of the container 101.

  In the present invention, the shape, size, and material of the discharge port 103 are not limited. The shape of the discharge port 103 may be a straight tube as shown in FIG. 6, or a branch may be provided in the middle. The discharge port 103 may be one place or a plurality of places.

  The cooling unit 104 is preferably provided with a heat dissipation unit 303. When a thermoelectric element is used as the cooling unit 104, the back of the cooling surface is a heat generating surface. The heat radiation part 303 is used for releasing heat from the heat generating surface. By releasing heat from the heat generating surface, the thermoelectric element can be operated efficiently. The heat radiation part 303 is preferably a fin, and more preferably a cooling fan is attached to the fin. Further, the heat radiation part 303 may be a water cooling mechanism. The heat dissipating part 303 is preferably formed of a material having high thermal conductivity. The material of the heat dissipation part 303 is preferably a metal, a semiconductor, or the like.

  The cooling unit 104 is preferably provided with a heat insulating unit 304. By providing the heat insulating portion 304, portions other than the atomizing electrode portion 105 are not cooled. The heat insulating part 304 is preferably made of a material having a low thermal conductivity. The material of the heat insulating portion 304 is preferably rubber, ceramics, glass or the like, but may be an air gap. The contents of the air gap are preferably air, nitrogen or the like. The heat insulating part 304 is preferably a non-conductor.

From the viewpoint of suppressing heat conduction, the contact area between the atomizing electrode portion 105 and the heat insulating portion 304 is preferably small, and specifically, it is preferably 10 μm ² or more and 10 mm ² or less.

  The atomizing electrode part 105 is preferably provided with an insulating part 305. The insulating unit 305 electrically insulates the atomizing electrode unit 105 and the container 101. The material of the insulating portion 305 is preferably an insulator such as Teflon (registered trademark), Delrin (registered trademark), or PEEK (registered trademark). In order to keep an excess condensate, it is preferable to provide a storage part in the insulating part 305. The reservoir is preferably a groove structure, an uneven structure, an absorber, or the like. In the present invention, the shape, material, and position of the insulating portion 305 are not limited.

From the viewpoint of suppressing heat conduction, the contact area between the atomizing electrode portion 105 and the insulating portion 305 is preferably small, and specifically, it is preferably 10 μm ² or more and 10 mm ² or less. In order to suppress dew condensation of water vapor, it is preferable to use a material with low thermal conductivity for the insulating portion 305 or to have a structure for suppressing heat conduction.

  The counter electrode unit 106 is preferably provided at a position where the sample gas 203 and the dopant 205 are mixed. The counter electrode unit 106 is preferably in the vicinity of the inlet 102 and the supply port 109.

  The chemical substance recovery unit 107 is preferably provided at a position where direct condensation of the sample gas 203 and the dopant 205 is suppressed. The distance between the injection port 102 and the chemical substance recovery unit 107 is preferably larger than the distance between the injection port 102 and the atomization electrode unit 105. The distance between the supply port 109 and the chemical substance recovery unit 107 is preferably larger than the distance between the supply port 109 and the atomization electrode unit 105.

  The chemical substance recovery unit 107 is preferably provided with a second insulating unit 306. The second insulating unit 306 electrically insulates the chemical substance recovery unit 107 and the container 101. The material of the second insulating portion 306 is preferably an insulator such as Teflon (registered trademark), Delrin (registered trademark), or PEEK (registered trademark). In order to keep the excess condensate, it is preferable to provide a storage part in the second insulating part 306. The reservoir is preferably a groove structure, an uneven structure, an absorber, or the like. In the present invention, the shape, material, and position of the second insulating portion 306 are not limited.

From the viewpoint of suppressing heat conduction, the contact area between the chemical substance recovery unit 107 and the second insulating unit 306 is preferably small, and specifically, it is preferably 10 μm ² or more and 10 mm ² or less.

  The second cooling part 108 is preferably provided with a second heat radiating part 307. When a thermoelectric element is used as the second cooling unit 108, the back of the cooling surface is a heat generating surface. The second heat radiating portion 307 is used for releasing heat from the heat generating surface. By releasing heat from the heat generating surface, the thermoelectric element can be operated efficiently. The second heat radiation part 307 is preferably a fin, and more preferably a fin is attached to the fin. The second heat radiating unit 307 may be a water cooling mechanism. The second heat radiating part 307 is preferably formed of a material having high thermal conductivity. The material of the second heat radiation part 307 is preferably a metal, a semiconductor, or the like.

  The second cooling part 307 is preferably provided with a second heat insulating part 308. By providing the second heat insulating part 308, the parts other than the chemical substance recovery part 107 are not cooled. The second heat insulating portion 308 is preferably made of a material having a low thermal conductivity such as rubber, ceramics, or glass. The second heat insulating part 308 may be an air gap. The contents of the air gap are preferably air, nitrogen or the like.

From the viewpoint of suppressing heat conduction, the contact area between the chemical substance recovery unit 107 and the second heat insulating unit 308 is preferably small, and specifically 10 μm ² or more and 10 mm ² or less.

  It is preferable to provide a chemical substance transport unit 309 and a chemical substance detection unit 310 in the vicinity of the chemical substance recovery unit 107. The chemical substance transport unit 309 is used to transport the chemical substance recovered by the chemical substance recovery unit 107 to the chemical substance detection unit 310. The chemical substance transport unit 309 may be a syringe, capillary, tube, porous body, or the like, and may include a pump. Since a high voltage is applied to the chemical substance recovery unit 107, the chemical substance transport unit 309 is preferably electrically insulated from the chemical substance recovery unit 107.

  The chemical substance transport unit 309 is preferably movable, and is preferably movable in at least one of the X direction, the Y direction, and the Z direction. In addition, the X direction said here means the longitudinal direction of the chemical substance conveyance part 309 of FIG. The Y direction and the Z direction are each orthogonal to the X direction. The chemical substance transport unit 309 is preferably movable in the θ direction. The θ direction referred to here is a direction in which the chemical substance transport unit 309 is rotated in the vertical direction with a place where the chemical substance transport unit 309 is fixed to the container 101 as a fulcrum. In addition, you may rotate to a horizontal direction by using the location which fixes the chemical substance conveyance part 309 to the container 101 as a fulcrum.

  The chemical substance transport unit 309 may be inside the container 101, may be at one end of the chemical substance recovery unit 107, or may be outside the container 101.

  The chemical substance detection unit 310 is preferably a chemical sensor, a biological sensor, etc., but MOSFET (metal-oxide-semiconductor field effect transistor), ISFET (ion-sensitive field effect transistor), bipolar transistor, organic thin film transistor, optode, metal oxide Semiconductor sensor, quartz microbalance (QCM), surface acoustic wave (SAW) element, solid electrolyte gas sensor, electrochemical cell sensor, surface wave plasmon resonance (SPR), Langmuir-Blodgett film (LB film) sensor, AFM, DNA sensor A protein sensor, an immune sensor, a microorganism sensor, or the like may be used. Moreover, the chemical substance detection part 310 is gas chromatograph (GC), GC-MS, GC-TOF / MS, a high performance liquid chromatograph (LC), HPLC, HPLC / IC, LC-TOF / MS, MALDI, nuclear magnetic resonance. An apparatus (NMR), SIMS, ICP mass spectrometer, etc. may be used. The chemical substance detection unit 310 may be provided at one place as shown in FIG. When providing the some chemical substance detection part 310, the same kind may be sufficient and multiple types may be sufficient.

  The chemical substance detection unit 310 may be outside the container 101, inside the container 101, or at one end of the chemical substance recovery unit 107.

  7-10 is explanatory drawing which shows operation | movement of the electrostatic spraying apparatus of Embodiment 2. FIG. 7 to 10, the same components as those in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted.

<Injection process>
In the injection step, a sample gas 203 containing water vapor 201 and a chemical substance 202 is injected into the container 101 through the injection port 102. FIG. 7A shows an injection process. In FIG. 7A, only two types of chemical substances 202, ie, chemical substances 202a and 202b are shown, but one kind may be used, or three or more kinds may be used. The relative humidity in the sample gas 203 is preferably 50% or more, and more preferably 80% or more. In the injection step, water vapor 201 may be added to the sample gas 203. In the present invention, the type and concentration of the chemical substance 202 are not limited. The sample gas 203 preferably contains a polar organic solvent. In the present invention, the type and concentration of the polar organic solvent are not limited.

  The sample gas 203 may collide with the inner wall of the container 101, the counter electrode unit 106, or the chemical substance recovery unit 107. Alternatively, the sample gas 203 may collide with a barrier 302 or a maze provided inside the container 101.

  In order to determine that the inside of the container 101 is filled with the sample gas 203, the chemical substance detection unit 310 may be used, or a chemical substance detection unit different from the chemical substance detection unit 310 may be used. Further, the chemical substance detection unit 310 may be one or plural.

<First condensate production step>
Next, in the first condensate generation step, the atomizing electrode unit 105 is cooled to a dew point temperature of the water vapor 201 or lower by the cooling unit 104. A first condensate 204 containing water vapor 201 and chemical substance 202 is formed on the outer peripheral surface of the atomizing electrode portion 105. FIG. 7B shows the first condensate production step.

<Supply process>
In the supply step, the dopant 205 is supplied to the container 101. FIG. 8A shows the supply process. The dopant 205 is supplied to the container 101 through the supply port 109. The dopant 205 is preferably impacted against the barrier 302.

<Dopant cooling step>
In the dopant cooling step, the dopant 205 is cooled on the outer peripheral surface of the atomizing electrode portion 105. FIG. 8B shows a dopant cooling step.

<Dissolution process>
In the dissolving step, the dopant 205 is dissolved in the first condensate 204. FIG. 9A shows the dissolution process.

<First charged fine particle forming step>
Next, in the first charged fine particle forming step, a large number of first charged fine particles 206 are formed from the first condensate 204. FIG. 9B shows the first charged fine particle forming step. The first charged fine particle 206 may be a cluster composed of one molecule to several tens of molecules, a fine particle composed of several tens to several hundred molecules, or a droplet composed of several hundred or more. There may be. Or these two or more types may be mixed.

  In the first charged fine particle forming step, the first charged fine particle 206 may contain electrically neutral molecules, ions or radicals derived from the sample gas 203.

  In the first charged fine particle forming step, the first charged fine particle 206 is preferably negatively charged. When the first charged fine particles 206 are negatively charged, it is preferable that the electron affinity of the chemical substance 202 is greater than the electron affinity of water. When the first charged fine particles 206 are negatively charged, the electron affinity of the dopant 205 is preferably larger than the electron affinity of water and the chemical substance 202.

  In the first charged fine particle forming step, the first charged fine particle 206 may be positively charged. When the first charged fine particles 206 are positively charged, the ionization energy of the chemical substance 202 is preferably smaller than the ionization energy of water. When the first charged fine particles 206 are positively charged, the ionization energy of the dopant 205 is preferably smaller than the ionization energy of water and the chemical substance 202.

  The method of turning the first condensate 204 into charged fine particles is most preferably electrostatic spraying. The principle of electrostatic spraying is as follows. The first condensate 204 is conveyed to the tip of the atomization electrode unit 105 by a voltage applied between the atomization electrode unit 105 and the counter electrode unit 106. The liquid level of the first condensate 204 rises in a conical shape toward the counter electrode 106 due to the Coulomb attractive force. When condensation further proceeds on the outer peripheral surface of the atomizing electrode portion 105, a conical first condensate 204 grows. Thereafter, the electric charge concentrates on the tip of the first condensate 204 and the Coulomb force increases. When the Coulomb force exceeds the surface tension of water, the first condensate 204 is split and scattered to form the first charged fine particles 206.

  In the first charged fine particle forming step, it is most preferable to apply a DC voltage between the atomizing electrode portion 105 and the counter electrode portion 106. It is preferable to apply a voltage at which corona discharge does not occur. Specifically, a DC voltage of 4 kV to 6 kV is preferable. Although it is most preferable to apply a negative voltage to the atomizing electrode unit 105 with respect to the counter electrode unit 106, a positive voltage may be applied. The counter electrode portion 106 is most preferably a GND electrode.

  An alternating voltage may be applied between the atomizing electrode portion 105 and the counter electrode portion 106, or a pulse voltage may be applied.

<Second charged fine particle forming step>
Next, in the second charged fine particle forming step, the first charged fine particles 206 and the sample gas 203 may be mixed into the second charged fine particles 311 in the container 101. FIG. 10A shows the second charged fine particle forming step. The sample gas 203 can be charged by mixing the first charged fine particles 206 and the sample gas 203. In order to efficiently mix the first charged fine particles 206 and the sample gas 203, the sample gas 203 preferably generates turbulent flow, spiral flow, vortex flow, and the like. The flow direction of the first charged fine particles 206 and the flow direction of the sample gas 203 may be orthogonal to each other, or may be a counter flow. The container 101 is preferably a cross channel or a T-shaped channel. The second charged fine particles 311 may be mixed with the sample gas 203 to form third charged fine particles.

<Second charged fine particle forming step>
In the second charged fine particle forming step, most of the first charged fine particles 206 move from the atomizing electrode portion 105 to the chemical substance recovery portion 107 via the counter electrode portion 106. Therefore, it is preferable to provide the injection port 102 at a position where the sample gas 203 is injected between the atomizing electrode unit 105 and the chemical substance recovery unit 107. The injection port 102 is preferably provided at a position where the sample gas 203 is injected between the atomizing electrode unit 105 and the counter electrode unit 106, but the sample is positioned between the counter electrode unit 106 and the chemical substance recovery unit 107. The injection port 102 can be provided at a position where the gas 203 is injected. The sample gas 203 may be focused on the path of the first charged fine particles 206.

  The diameter of the second charged fine particle 311 is preferably larger than the diameter of the first charged fine particle 206. From the viewpoint of the stability of the second charged fine particles 311, the diameter of the second charged fine particles 311 is preferably 1 nm or more and 30 nm or less. The second charged fine particle 311 may be a cluster composed of one molecule to several tens of molecules, a fine particle composed of several tens to several hundred molecules, or a droplet composed of several hundreds or more. There may be. Or these two or more types may be mixed.

  The second charged fine particles 311 may contain electrically neutral molecules, ions, radicals, and the like. In the second charged fine particle forming step, it is preferable that the charge signs of the first charged fine particle 206 and the second charged fine particle 311 are the same. However, the second charged fine particle 311 may be negatively charged or positively charged. You may do it.

The charge amount of the second charged fine particles 311 is preferably the same as that of the first charged fine particles 206. The charge amount of the second charged fine particles 311 is preferably the same amount or more and 10 times or less as the elementary charge amount (1.6 × 10 ⁻¹⁹ C) per fine particle.

<Recovery process>
Finally, in the recovery step, the first charged fine particles 206 and the second charged fine particles 311 are recovered to the chemical substance recovery unit 107. FIG. 10B shows the recovery process. In the recovery step, it is preferable that the first charged fine particles 206 and the second charged fine particles 311 are simultaneously recovered to the chemical substance recovery unit 107. In the present invention, the ratio of the first charged fine particles 206 and the second charged fine particles 311 collected by the chemical substance collecting unit 107 is not limited. In the recovery step, the sample gas 203 may be recovered directly to the chemical substance recovery unit 107. It is preferable that the amount of the sample gas 203 recovered directly to the chemical substance recovery unit 107 is small. During the recovery process, the injection process is preferably stopped.

  In the recovery step, it is preferable to recover the first charged fine particles 206 and the second charged fine particles 311 by electromagnetic force, but they may be recovered by electrostatic force. It is preferable to apply a DC voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. The DC voltage is preferably from 0.01 kV to 6 kV, and more preferably from 0.01 kV to 0.5 kV.

  When the first charged fine particles 206 and the second charged fine particles 311 have negative charges, it is most preferable to apply a positive voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. When the first charged fine particles 206 and the second charged fine particles 311 have a positive charge, it is preferable to apply a negative voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. The voltage application is preferably continuous, but may be pulsed. The counter electrode portion 106 is most preferably a GND electrode. An AC voltage is preferably applied between the chemical substance recovery unit 107 and the counter electrode unit 106, but a pulse voltage may be applied.

  The chemical substance recovery unit 107 is preferably cooled below the dew point temperature of the water vapor 201. It is preferable that the first charged fine particles 206 and the second charged fine particles 311 are used as the recovered liquid 207 on the outer peripheral surface of the chemical substance recovery unit 107. In the initial stage of the recovery process, it is preferable that the recovery liquid 207 is in the form of droplets on the outer peripheral surface of the chemical substance recovery unit 107. In the progress stage of the recovery process, it is preferable that the outer peripheral surface of the chemical substance recovery unit 107 is covered with the recovery liquid 207. The chemical substance recovery unit 107 is preferably needle-shaped, and the recovery liquid 207 is preferably recovered at the tip of the chemical substance recovery unit 107. The outer peripheral surface of the chemical substance recovery unit 107 is preferably hydrophilic, but may be water repellent.

  The chemical substance recovery unit 107 is preferably cooled by the second cooling unit 108. The chemical substance recovery unit 107 can be cooled to a temperature equal to or lower than the dew point temperature of water vapor by the second cooling unit 108. In the recovery step, it is preferable to control the temperature of the second cooling unit 108 so that the amount of the recovery liquid 207 does not become excessive. The temperature of the chemical substance recovery unit 107 may be equal to or higher than the freezing point of the recovery liquid 207 or may be equal to or lower than the freezing point of the recovery liquid 207.

  The chemical substance recovery unit 107 is preferably directed downward. As shown in FIG. 6, it is preferable to collect the recovery liquid 207 at the tip of the chemical substance recovery unit 107 by gravity.

  In the recovery step, it is preferable to recover the recovery liquid 207 at the tip of the chemical substance recovery unit 107 by electrostatic force as shown in FIG. The tip of the chemical substance recovery unit 107 is preferably shaped to concentrate the electric field. The chemical substance recovery unit 107 is most preferably needle-shaped. On the outer peripheral surface of the chemical substance recovery unit 107, the recovery liquid 207 preferably moves to the tip of the chemical substance recovery unit 107 by electrostatic force. The recovered liquid 207 preferably contains a polar organic compound and / or water.

  In the recovery step, it is preferable that the recovery liquid 207 is transferred to the chemical substance detection unit 310 by the chemical substance transfer unit 309. In order to transport the recovered liquid 207, a syringe, capillary, tube, porous body, or the like may be used. A pump, capillary force, or the like may be used to drive the recovery liquid 207. The temperature of the chemical transport unit 309 is preferably room temperature, but may be cooled below the dew point temperature of water vapor.

  While applying a voltage to the chemical substance recovery unit 107 with respect to the counter electrode unit 106, the chemical substance transport unit 309 is preferably separated from the chemical substance recovery unit 107, and most preferably physically separated. . In order to separate the chemical substance transport unit 309 from the chemical substance recovery unit 107, the chemical substance transport unit 309 is preferably movable. In the recovery step, the chemical substance transport unit 309 may be electrically separated from the chemical substance recovery unit 107 while a voltage is applied to the chemical substance recovery unit 107 with respect to the counter electrode unit 106.

  The chemical substance 202 contained in the recovered liquid 207 is preferably detected by the chemical substance detection unit 310. The chemical substance 202 to be detected may be one type or two or more types. The chemical substance 202 is preferably ketones, amines, alcohols, aromatic hydrocarbons, aldehydes, esters, organic acids, hydrogen sulfide, methyl mercaptan, disulfide, and the like, and alkane, alkene, alkyne, diene, alicyclic ring. Also preferred are formula hydrocarbons, allenes, ethers, carbonyls, carbanio, proteins, polynuclear aromatics, heterocycles, organic derivatives, nucleic acids, ribonucleic acids, antibodies, biomolecules, metabolites, isoprene, isoprenoids and derivatives thereof. In the recovery process, it is preferable that the chemical substance 202 is quantified by the chemical substance detection unit 310, but only the presence of the chemical substance 202 may be detected.

  Interfering substances other than the water vapor 201 and the detection target substance contained in the recovered liquid 207 may be removed. In order to remove interfering substances from the recovered liquid 207, a filter or an adsorbent may be used, or other removal methods may be used.

  In the present embodiment, at least two steps from the injection step to the recovery step described above may be performed simultaneously. That is, for example, the injection step and the first condensate generation step may be performed simultaneously. Or you may perform each process in order.

  In the present embodiment, the first charged fine particles 206 and the second charged fine particles 311 may be heated. The concentration of the chemical substance 202 may be increased by heating the first charged fine particles 206 and the second charged fine particles 311. In order to heat the first charged fine particles 206 and the second charged fine particles 311, it is preferable to use infrared light. When the first charged fine particles 206 and the second charged fine particles 311 are heated by infrared light, it is preferable to use the wavelength of the water absorption peak. It is preferable that infrared light for heating the first charged fine particles 206 and the second charged fine particles 311 is not irradiated to the atomizing electrode unit 105 and the chemical substance recovery unit 107. Infrared light for heating the first charged fine particles 206 and the second charged fine particles 311 is preferably focused.

  Infrared light for heating the first charged fine particles 206 and the second charged fine particles 311 is preferably guided in the container 101. In that case, it is preferable to provide an optical waveguide in the container 101. It is also preferable to provide an infrared light window in a part of the container 101. A heater may be used to heat the first charged fine particles 206 and the second charged fine particles 311.

  The chemical substance recovery unit 107, the chemical substance transport unit 309, or the chemical substance detection unit 310 is preferably separable from the container 101. The chemical substance recovery unit 107, the chemical substance transport unit 309, or the chemical substance detection unit 310 is preferably washable, but may be disposable.

  Corona discharge may be used in the first charged fine particle forming step and / or the second charged fine particle forming step, but electrostatic spraying is most preferably used. However, when the relative humidity in the sample gas 203 is low, or when the sufficient first condensate 204 is not generated on the outer peripheral surface of the atomizing electrode unit 105, the electrostatic spray may be accompanied by corona discharge. Therefore, in the present invention, the first charged fine particle forming step and / or the second charged fine particle forming step is not limited to electrostatic spraying.

  In the first charged fine particle forming step and / or the second charged fine particle forming step, according to the current flowing between the atomizing electrode portion 105 and the counter electrode portion 106, between the atomizing electrode portion 105 and the counter electrode portion 106. It is preferable to control the voltage application. When a current of a threshold value or more flows between the atomizing electrode unit 105 and the counter electrode unit 106, it is preferable to interrupt the voltage application between the atomizing electrode unit 105 and the counter electrode unit 106, but the applied voltage is reduced. May be. Further, the voltage application may be resumed when the current flowing between the atomizing electrode unit 105 and the counter electrode unit 106 becomes equal to or less than the threshold value.

  In order to remove the water vapor 201, the chemical substance 202, or the dopant 205 from the atomizing electrode unit 105, it is preferable to heat the atomizing electrode unit 105. When the atomizing electrode unit 105 is heated, it is preferable to inject clean gas into the container 101. The clean gas preferably does not contain water vapor 201, chemical substance 202, or dopant 205.

  In order to remove the water vapor 201, the chemical substance 202 or the dopant 205 by heating the atomizing electrode part 105, it is also preferable to use a thermoelectric element. The thermoelectric element is preferably the cooling unit 104. Use of a thermoelectric element is convenient because the cooling surface and the heating surface can be easily reversed. Further, if the same thermoelectric element is used for the condensation step and the removal of water vapor 201, the removal of chemical substance 202 or the removal of dopant 205, it can contribute to the miniaturization of the analyzer. In order to detect the removal of the water vapor 201, the chemical substance 202 or the dopant 205, it is preferable to use the chemical substance detection part 310, but a chemical substance detection part different from the chemical substance detection part 310 may be used. .

  In order to remove the water vapor 201, the chemical substance 202, and the dopant 205 from the counter electrode unit 106, it is also preferable to heat the counter electrode unit 106. When heating the counter electrode portion 106, it is preferable to inject a clean gas into the container 101. The clean gas preferably does not contain water vapor 201, chemical substance 202, or dopant 205.

  In order to remove the water vapor 201, the chemical substance 202, or the dopant 205 by heating the counter electrode portion 106, it is preferable to use a thermoelectric element. Use of a thermoelectric element is convenient because the cooling surface and the heating surface can be easily reversed. In order to detect the removal of the water vapor 201, the chemical substance 202 or the dopant 205, it is preferable to use the chemical substance detection part 310, but a chemical substance detection part different from the chemical substance detection part 310 may be used. .

  In order to remove the water vapor 201, the chemical substance 202, or the dopant 205 from the chemical substance recovery unit 107, it is also preferable to heat the chemical substance recovery part 107. When the chemical substance recovery unit 107 is heated, it is preferable to inject a clean gas into the container 101. The clean gas preferably does not contain water vapor 201, chemical substance 202, or dopant 205.

  In order to remove the water vapor 201, the chemical substance 202, and the dopant 205 by heating the chemical substance recovery unit 107, it is preferable to use a thermoelectric element. The thermoelectric element is preferably the second cooling unit 108. Use of a thermoelectric element is convenient because the cooling surface and the heating surface can be easily reversed. In addition, if the same thermoelectric element is used for the recovery process and the removal of water vapor 201, the removal of chemical substance 202 or the removal of dopant 205, it can contribute to the downsizing of the analyzer. In order to detect the removal of the water vapor 201, the chemical substance 202 or the dopant 205, it is preferable to use the chemical substance detection unit 117, but a chemical substance detection unit different from the chemical substance detection unit 310 may be used. .

(Embodiment 3)
FIG. 11 is a schematic diagram of an electrostatic spraying apparatus according to Embodiment 3 of the present invention. In FIG. 11, the same components as those in FIG.

  The present embodiment is different from the first embodiment in that a supply port 109 is provided in the vicinity of the atomizing electrode unit 105. The dopant 205 may be added directly to the first condensate 204 from the supply port 109. The liquid dopant 205 may be supplied to the first condensate 204. A cooled dopant 205 may be supplied.

(Embodiment 4)
FIG. 12 is a schematic diagram of an electrostatic spraying device according to Embodiment 4 of the present invention. In FIG. 12, the same components as those in FIG.

  The present embodiment is different from the first embodiment in that a supply port 109 is provided in the sample gas generation unit 312. The dopant 205 is supplied from the upstream side of the sample gas generation unit 312. The dopant 205 is injected into the container 101 together with the sample gas 203. The sample gas generator 312 may be a bubbler, a sample bag, a living body respiratory device or a circulator.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are used only for illustrative purposes and should not be used to limit the present invention.

[Example 1]
The container 101 was manufactured by cutting an aluminum plate having a thickness of 4 mm. The container 101 was a cuboid of 38 mm × 38 mm × 18 mm. A part of the container 101 can be replaced with an acrylic resin plate. It is more preferable to use a transparent material for a part of the container because the formation process of the condensate can be observed. The inner wall of the container 101 was polished smoothly to suppress gas adsorption.

  The container 101 can be opened and closed with a hinge 301.

  An inlet 102 was provided so as to communicate with the container 101. The injection port 102 was a stainless steel tube having an outer diameter of 1/8 inch and a length of 50 mm. The injection port 102 was provided horizontally at a position 10 mm from the bottom surface of the container 101 with respect to the bottom surface of the container 101.

  A discharge port 103 was provided at the other end of the container 101. The discharge port 103 was a stainless steel tube having an outer diameter of 1/8 inch and a length of 50 mm. The discharge port 103 was provided horizontally at a position 4 mm from the bottom surface of the container 101 with respect to the bottom surface of the container 101.

  A thermoelectric element was provided at one end of the container 101 as the cooling unit 104. One cooling part 104 is provided in the container 101. The size of the cooling unit 104 was 14 mm × 14 mm × 1 mm. The maximum heat absorption of the cooling unit 104 was 0.9 W, and the maximum temperature difference was 69 ° C. The cooling surface of the cooling unit 104 was covered with a ceramic material. Since the ceramic material has fine irregularities and a porous structure on the surface thereof, it is possible to efficiently cool the contacting object.

  The cooling unit 104 is provided with heat radiation fins as the heat radiation unit 303. The heat radiating fins of the heat radiating portion 303 were made of aluminum by cutting, the number of fins was 6, and the size of the fins was 16 mm × 15 mm × 1 mm. A cooling fan (KD1208PTB2-6, SUNON) for promoting heat dissipation was provided in the vicinity of the heat dissipation part 303.

  A heat insulating part 304 was provided between the cooling part 104 and the container 101. A rubber film having a thickness of 1 mm was used as the heat insulating part 304. A part of the rubber film was provided with a hole for penetrating the atomizing electrode part 105. The diameter of the hole was 1 mm.

  An atomizing electrode unit 105 was provided at one end of the cooling unit 104. Inside the container 101, a stainless needle was provided as the atomizing electrode portion 105. The length of the stainless needle was 3 mm, and the diameter was 0.79 mm at the thickest part and 0.5 mm at the thinnest part. In addition, a sphere having a diameter of 0.72 mm was provided at the tip of the stainless needle so that the first charged fine particle forming step could be performed stably. Thermal conduction grease (SCH-20, Sunhayato) was applied between the atomizing electrode part 105 and the cooling part 104.

  The atomizing electrode portion 105 was provided with a Teflon (registered trademark) disk having a diameter of 10 mm and a thickness of 3 mm as the insulating portion 305. A concave structure having a diameter of 4 mm and a depth of 1 mm was provided at the center of the insulating part 305.

  The counter electrode portion 106 was provided at a position 3 mm away from the tip of the atomizing electrode portion 105. As the counter electrode portion 106, an annular stainless steel plate having an outer diameter of 12 mm, an inner diameter of 8 mm, and a thickness of 0.5 mm was used.

  A chemical substance recovery unit 107 was provided at the other end of the container 101. A stainless needle was provided as a chemical substance recovery unit 107 inside the container 101. The length of the stainless needle was 3 mm, and the diameter was 0.79 mm at the thickest part and 0.5 mm at the thinnest part. In addition, the tip of the stainless steel needle is sharply polished so that chemicals can be collected efficiently.

  The chemical substance recovery unit 107 was provided with a Teflon (registered trademark) disk having a diameter of 10 mm and a thickness of 3 mm as the second insulating unit 306. A concave structure having a diameter of 4 mm and a depth of 1 mm was provided at the center of the second insulating portion 306.

  A second cooling unit 108 is provided at one end of the chemical substance recovery unit 107. The size of the second cooling unit 108 was 14 mm × 14 mm × 1 mm. The maximum heat absorption of the second cooling unit 108 was 0.9 W, and the maximum temperature difference was 69 ° C. The cooling surface of the second cooling unit 108 was covered with a ceramic material. Since the ceramic material has fine irregularities and a porous structure on the surface thereof, it is possible to efficiently cool the contacting object.

  The second cooling unit 108 is provided with heat radiation fins as the second heat radiation unit 307. The heat radiating fins of the second heat radiating portion 307 were made of aluminum by cutting, the number of fins was 6, and the size of the fins was 16 mm × 15 mm × 1 mm. A cooling fan (KD1208PTB2-6, SUNON) was provided in the vicinity of the second heat radiating portion 114 to promote heat radiation.

  A rubber film having a thickness of 1 mm was provided as the second heat insulating part 308 between the second cooling part 108 and the container 101. A part of the rubber film was provided with a hole for penetrating the atomizing electrode part 105. The diameter of the hole was 1 mm.

  Thermal conductive grease (SCH-20, Sunhayato) was applied between the chemical substance recovery unit 107 and the second cooling unit 108.

  In addition, the inlet 112 and the outlet 103 were provided with a valve 112a and a valve 112b, respectively.

  Next, the operation procedure of the electrostatic spraying apparatus 100 will be described.

  In the injection step, the sample gas 203 was injected into the container 101 from the injection port 102. As the sample gas 203, nitrogen gas containing volatile components from mouse urine was used. The method for preparing the sample gas 203 is as follows.

  First, 0.2 mL of mouse urine is filled into a 1 mL glass vial. The vial was provided with a nitrogen gas inlet and outlet. Nitrogen gas (purity 99.99%) was introduced from the nitrogen gas inlet and sprayed onto the mouse urine. Nitrogen gas used was passed through a 100 mL bubbler of pure water. Nitrogen gas containing volatile components in mouse urine was taken out from the outlet and used as sample gas 203. As a dopant 205, 0.3% acetic acid (special grade, Cat-No. 017-00256, Wako Pure Chemical Industries) was mixed into mouse urine.

  The injection speed of the sample gas 203 into the container 101 was 500 sccm. The temperature of the sample gas 203 was room temperature (22 ° C.).

  Before the sample gas 203 was injected into the container 101 in the injection step, the inside of the container 101 was filled with dry nitrogen gas.

  In the injection step, excess sample gas 203 was discharged through the discharge port 103.

  In the injection process, the inside of the container 101 was set to atmospheric pressure.

  In the first condensate production step, the atomizing electrode portion 105 was cooled to 15 ° C. by a thermoelectric element.

  A first condensate 204 was formed on the outer peripheral surface of the atomizing electrode portion 105 after 5 seconds from the operation of the thermoelectric element. In the initial stage of formation of the first condensate 204, the droplets had a diameter of 10 μm or less. The droplets grew with the passage of time, and the entire surface of the atomizing electrode portion 105 was covered with the first condensate 204. Formation of the 1st condensate 204 in the outer peripheral surface of the atomization electrode part 105 was observed using the microscope (the KEYENCE company make, VH-6300). FIG. 13 is a photograph showing a state in which the first condensate 204 is formed on the outer peripheral surface of the atomizing electrode portion 105. In the first condensate generation step, as shown in FIG. 13, droplets 401 of the first condensate were formed on the outer peripheral surface of the atomizing electrode portion 105.

  Next, in the first charged fine particle forming step, the first condensate 204 was made into a large number of first charged fine particles 206. The first charged fine particle forming step was performed by electrostatic spraying. As described in the first embodiment, corona discharge occurs at the initial stage of electrostatic spraying, but this may be included in the first charged fine particle forming step of the present invention.

  The diameter of the first charged fine particles 206 is preferably 2 nm or more and 30 nm or less from the viewpoint of the stability of the charged fine particles. The first charged fine particles 206 are preferably present one by one, but a plurality may be bonded. In the present invention, the shape of the first charged fine particles 206 is not limited. A spherical shape, a flat shape, or a spindle shape may be used.

  DC 5 kV was applied between the atomizing electrode part 105 and the counter electrode part 106. The atomizing electrode portion 105 is a cathode, and the counter electrode portion 106 is a GND electrode. The same effect can be obtained by using the atomizing electrode portion 105 as an anode and the counter electrode portion 106 as a GND electrode. In this case, the first charged fine particle forming step is relatively unstable.

  In the first charged fine particle forming step, a conical water column called a tailor cone was formed at the tip of the atomizing electrode portion 105. A number of first charged fine particles 206 including the chemical substance 202 were released from the tip of the tailor cone. FIG. 14 is a diagram for explaining the generation of the tailor cone 402 and the first charged fine particles 206. The first condensate 204 was sequentially conveyed toward the tip of the atomizing electrode unit 105. As shown in FIG. 14 (a), the tailor cone 402 was formed at the tip of the atomizing electrode portion 105. FIG.14 (b) traces the microscope photograph of Fig.14 (a). The first charged fine particles 206 were emitted from the tip of the tailor cone 402, that is, the place where the electric field is concentrated. In this embodiment, the tailor cone 402 was formed 7 seconds after the start of the injection of the sample gas 203.

  In the first charged fine particle forming step, the current flowing between the atomizing electrode portion 105 and the counter electrode portion 106 was monitored. When excessive current flowed, the voltage application between the atomizing electrode part 105 and the counter electrode part 106 was interrupted or the applied voltage was reduced.

  In the second charged fine particle forming step, the first charged fine particle 206 and the sample gas 203 were mixed. In order to perform the second charged fine particle forming step, the sample gas 203 was collided toward the counter electrode portion 106 and the inner wall of the container 101. By causing the sample gas 203 to collide with the counter electrode unit 106 and the inner wall of the container 101, the first charged fine particles 206 and the sample gas 203 can be mixed efficiently. The injection speed of the sample gas 203 into the container 101 was 500 sccm.

  In the recovery step, the first charged fine particles 206 and the second charged fine particles 311 were recovered to the chemical substance recovery unit 107 by electrostatic force. A voltage of +500 V was applied to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. The recovery process was performed in parallel with the injection process, the first condensate generation process, the first charged fine particle forming process, and the second charged fine particle forming process. From the viewpoint of the lifetime of the first charged fine particles 206 and the second charged fine particles 311, it is preferable to perform the recovery step within 10 minutes at the latest after the start of the first charged fine particle step and the second charged fine particle step.

  In the recovery process, the first charged fine particles 206 and the second charged fine particles 311 were cooled and condensed in the chemical substance recovery unit 107. The temperature of the chemical substance recovery unit 107 was 15 ° C. Six minutes after the injection process was started, 1.5 μL of recovery liquid 207 was obtained in the chemical substance recovery unit 107. The collected charged fine particles are most preferably liquefied, but may be in a mist state. The first charged fine particles 206 and the second charged fine particles 311 may be dissolved in an aqueous solution or gel.

  FIG. 15 is a microscope photograph of the recovery liquid 207 in the chemical substance recovery unit 107. Droplets of the recovered liquid 207 could be observed on the outer peripheral surface of the chemical substance recovery unit 107.

  In the recovery step, 1 μL of the recovered liquid 207 obtained was collected with a Hamilton syringe (802N 25 μL HAMILTON). The collected recovered liquid 207 was introduced into a gas chromatography apparatus, and the chemical substance 202 was analyzed.

  The gas chromatography apparatus used was GC-4000 (GL Science). A capillary column (Inert Cap Pure WAX) was used as the analytical column. The capillary column had an inner diameter of 0.25 mm, a length of 30 m, and a df of 0.25 μm. The carrier gas was helium. The oven temperature was a starting temperature of 40 ° C., a heating rate of 4 ° C./min, and a final temperature of 200 ° C. The injection temperature and the flame ionization detector (FID) temperature were 250 ° C., respectively.

  FIG. 16 shows the result of analyzing the collected liquid 207. In FIG. 16, the chromatogram described as before concentration is the result of analyzing 25 μL of the sample gas 203. In FIG. 16, the chromatogram described after concentration (no dopant) is the result of analyzing 1 μL of the recovered liquid 207 obtained by operating the electrostatic spraying apparatus 100 without mixing the dopant 205 with the sample gas 203. It is. In FIG. 16, the chromatogram described after concentration (with dopant) is the result of analyzing 1 μL of the recovered liquid 207 obtained by mixing the dopant 205 with the sample gas 203 and operating the electrostatic spraying device 100. is there. In FIG. 16, the peak of the chromatogram after concentration (no dopant) may be larger than the peak of the chromatogram before concentration. This result indicates that the chemical substance 202 contained in the sample gas 203 is concentrated. In FIG. 16, the peak of the chromatogram after concentration (no dopant) was larger than the peak of the chromatogram before concentration. This result indicates that the chemical substance 202 contained in the sample gas 203 is concentrated. In FIG. 16, the peak of the chromatogram after concentration (with dopant) was larger than the peak of the chromatogram before concentration. This result indicates that the chemical substance 202 contained in the sample gas 203 is concentrated. When the dopant 205 was added to the sample gas 203, there was a chemical substance 202 that was more concentrated than when the dopant 205 was not added to the sample gas 203.

  FIG. 17 is an enlarged view of a part of the analysis result of FIG. In FIG. 17, the chromatogram of the dopant 205 is shown as a reference. The chemical substance 202 in the sample gas 203 was concentrated by the electrostatic spraying apparatus 100. By mixing the dopant 205 with the sample gas 203, the chemical substance 202 in the sample gas 203 was more efficiently concentrated. When the dopant 205 was mixed with the sample gas 203, the chemical substance 202 of the sample gas 203 was concentrated 1250 times.

  In the recovery process, the chemical substance recovery unit 107 was removed from the container 101. The removed chemical substance recovery unit 107 was washed with methanol.

  In the recovery step, the atomizing electrode unit 105 was heated to remove the chemical substance 202. A thermoelectric element was used for heating the atomizing electrode portion 105. In addition, this thermoelectric element used the same thing as when the atomization electrode part 105 was cooled in the 1st condensate production | generation process. When the atomizing electrode part 105 was heated, the polarity of the voltage applied to the thermoelectric element was reversed from that when the atomizing electrode part 105 was cooled.

  In the recovery step, the atomizing electrode unit 105 was performed under a stream of dry nitrogen gas in order to remove the chemical substance 202. As a result, the chemical substance 202 can be quickly removed from the atomizing electrode portion 105. Dry nitrogen gas was introduced from the inlet 103.

  In the recovery step, the chemical substance recovery unit 107 was neutralized. Static elimination was performed by grounding the chemical substance recovery unit 107.

  In the first charged fine particle forming step and the second charged fine particle forming step, the current flowing between the atomizing electrode portion 105 and the counter electrode portion 106 was monitored. When an excessive current flowed, the voltage application between the atomizing electrode part 105 and the counter electrode part 106 was interrupted.

  In addition, when the case where the container 101 was provided and the case where the container 101 was not provided were compared, the sample gas 203 was more efficiently concentrated when the container 101 was provided.

  As shown in the present example, the chemical substance could be easily and efficiently concentrated by the electrostatic spraying device without using the nebulizer gas and the primary ion generating gas.

(Example 2)
In this embodiment, the description of the same components as those in Embodiment 1 is omitted.

  This embodiment is different from the first embodiment in that the kind of the dopant 205 is different. In this example, oxygen having an electron affinity higher than that of acetic acid was used as the dopant 205. Further, the present embodiment is different from the first embodiment in a method of mixing the dopant 205 into the sample gas 203. A dopant container was used to mix the dopant 205 with the sample gas 203.

  Next, the operation procedure of the electrostatic spraying apparatus 100 will be described.

  In the injection step, the sample gas 203 was injected into the container 101 from the injection port 102. As the sample gas 203, nitrogen gas containing volatile components from mouse urine was used. The method for preparing the sample gas 203 is as follows. First, 0.2 mL of mouse urine is filled into a 1 mL glass vial. The vial was provided with a nitrogen gas inlet and outlet. Nitrogen gas (purity 99.99%) was introduced from the nitrogen gas inlet and sprayed onto the mouse urine. Nitrogen gas used was passed through a 100 mL bubbler of pure water. The flow rate of nitrogen gas was 495 sccm. Nitrogen gas containing volatile components in mouse urine was taken out from the outlet and used as sample gas 203.

  Oxygen gas was mixed into the sample gas 203 using a dopant container. The flow rate of oxygen gas was 5 sccm.

  The temperature of the sample gas 203 and the dopant 205 was room temperature (22 ° C.).

  Before the sample gas 203 was injected into the container 101 in the injection step, the inside of the container 101 was filled with dry nitrogen gas.

  In the injection step, excess sample gas 203 was discharged through the discharge port 103.

  In the injection process, the inside of the container 101 was set to atmospheric pressure.

  In the first condensate production step, the atomizing electrode portion 105 was cooled to 15 ° C. by a thermoelectric element.

  A first condensate 204 was formed on the outer peripheral surface of the atomizing electrode portion 105 after 5 seconds from the operation of the thermoelectric element. In the initial stage of formation of the first condensate 204, the droplets had a diameter of 10 μm or less. The droplets grew with the passage of time, and the entire surface of the atomizing electrode portion 105 was covered with the first condensate 204.

  Next, in the first charged fine particle forming step, the first condensate 204 was made into a large number of first charged fine particles 206. The first charged fine particle forming step was performed by electrostatic spraying. As described in the first embodiment, corona discharge is generated in the initial stage of electrostatic spraying, but this may be included in the first charged fine particle forming step of the present invention.

  The diameter of the first charged fine particles 206 is preferably 2 nm or more and 30 nm or less from the viewpoint of the stability of the charged fine particles. The first charged fine particles 206 are preferably present one by one, but a plurality may be bonded. In the present invention, the shape of the first charged fine particles 206 is not limited. A spherical shape, a flat shape, or a spindle shape may be used.

  DC 5 kV was applied between the atomizing electrode part 105 and the counter electrode part 106. The atomizing electrode portion 105 is a cathode, and the counter electrode portion 106 is a GND electrode. The same effect can be obtained by using the atomizing electrode portion 105 as an anode and the counter electrode portion 106 as a GND electrode. In this case, the first charged fine particle forming step is relatively unstable.

  In the first charged fine particle forming step, a conical water column called a tailor cone was formed at the tip of the atomizing electrode portion 105. A number of first charged fine particles 206 including the chemical substance 202 were released from the tip of the tailor cone. The first charged fine particles 206 were emitted from the tip of the tailor cone 402, that is, the place where the electric field is concentrated. In this embodiment, the tailor cone 402 was formed 7 seconds after the start of the injection of the sample gas 203.

  In the first charged fine particle forming step, the current flowing between the atomizing electrode portion 105 and the counter electrode portion 106 was monitored. When excessive current flowed, the voltage application between the atomizing electrode part 105 and the counter electrode part 106 was interrupted or the applied voltage was reduced.

  In the second charged fine particle forming step, the first charged fine particle 206 and the sample gas 203 were mixed. In order to perform the second charged fine particle forming step, the sample gas 203 was collided toward the counter electrode portion 106 and the inner wall of the container 101. By causing the sample gas 203 to collide with the counter electrode unit 106 and the inner wall of the container 101, the first charged fine particles 206 and the sample gas 203 can be mixed efficiently. The injection speed of the sample gas 203 into the container 101 was 500 sccm.

  In the recovery step, the first charged fine particles 206 and the second charged fine particles 311 were recovered to the chemical substance recovery unit 107 by electrostatic force. A voltage of +500 V was applied to the chemical substance recovery unit 107 with respect to the counter electrode unit 106. The recovery process was performed in parallel with the injection process, the first condensate generation process, the first charged fine particle forming process, and the second charged fine particle forming process. From the viewpoint of the lifetime of the first charged fine particles 206 and the second charged fine particles 311, it is preferable to perform the recovery step within 10 minutes at the latest after the start of the first charged fine particle step and the second charged fine particle step.

  In the recovery process, the first charged fine particles 206 and the second charged fine particles 311 were cooled and condensed in the chemical substance recovery unit 107. The temperature of the chemical substance recovery unit 107 was 15 ° C. Six minutes after the injection process was started, 1.5 μL of recovery liquid 207 was obtained in the chemical substance recovery unit 107. The collected charged fine particles are most preferably liquefied, but may be in a mist state. In order to obtain a liquid state, the charged fine particles may be cooled and condensed, or dissolved in an aqueous solution or gel.

  In the recovery step, 1 μL of the recovered liquid 207 obtained was collected with a Hamilton syringe (802N 25 μL HAMILTON). The collected recovered liquid 207 was introduced into a gas chromatography apparatus, and the chemical substance 202 was analyzed.

  The gas chromatography apparatus used was GC-4000 (GL Science). A capillary column (Inert Cap Pure WAX) was used as the analytical column. The capillary column had an inner diameter of 0.25 mm, a length of 30 m, and a df of 0.25 μm. The carrier gas was helium. The oven temperature was a starting temperature of 40 ° C., a heating rate of 4 ° C./min, and a final temperature of 200 ° C. The injection temperature and the flame ionization detector (FID) temperature were 250 ° C., respectively.

  The result of analyzing the recovered liquid 207 is shown in FIG. In FIG. 18, the chromatogram described as before concentration is the result of analyzing 25 μL of the sample gas 203, and the chromatogram described as after concentration (nitrogen 100%) is obtained by mixing the dopant 205 with the sample gas 203. 1 is a result of analyzing 1 μL of the recovered liquid 207 obtained by operating the electrostatic spraying device 100. Further, in FIG. 18, the chromatogram described after concentration (nitrogen: oxygen = 99: 1) is a 1 μL recovery obtained by mixing the dopant 205 with the sample gas 203 and operating the electrostatic spraying apparatus 100. It is the result of analyzing the liquid 207.

  In FIG. 18, the peak of the chromatogram after concentration (nitrogen 100%) may be larger than the peak of the chromatogram before concentration. This result indicates that the chemical substance 202 contained in the sample gas 203 is concentrated. The peak of the chromatogram after concentration (100% nitrogen) was larger than the peak of the chromatogram before concentration, but this result indicates that the chemical substance 202 contained in the sample gas 203 is concentrated. Yes. Moreover, the peak of the chromatogram after concentration (nitrogen: oxygen = 99: 1) was larger than the peak of the chromatogram before concentration, but this result shows that the chemical substance 202 contained in the sample gas 203 is concentrated. It represents that.

  When the dopant 205 was added to the sample gas 203, there was a chemical substance 202 that was more concentrated than when the dopant 205 was not added to the sample gas 203. When the dopant 205 was mixed with the sample gas 203, the chemical substance 202 of the sample gas 203 was concentrated 1700 times.

  From the foregoing description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The sample gas concentration method according to the present invention can be applied to a mass spectrometer capable of simple and efficient trace analysis. It can be used in the environment such as biomolecule analyzers and air pollutant analyzers, food, housing, automobiles, and security fields. It can be used in the medical field such as a breath diagnosis apparatus and a stress measuring instrument, and in the health care field.

1 Ar gas for generating primary ions 2 Sample gas 10 APIMS
DESCRIPTION OF SYMBOLS 11 Mass spectrometry part 15 Ion generation part 19 Needle electrode 30 Mixing part 100 Electrostatic spray apparatus 101 Container 102 Inlet 103 Outlet 104 Cooling part 105 Atomization electrode part 106 Counter electrode part 107 Chemical substance recovery part 108 2nd cooling part 109 Supply unit 110 Valve 111 Mixer 112a, 112b Valve 201 Water vapor 202, 202a, 202b Chemical substance 203 Sample gas 204 First condensate 205 Dopant 206 First charged fine particle 207 Collected liquid 301 Hinge 302 Barrier 303 Heat dissipating unit 304 Heat insulating unit 305 Insulating unit 306 Second insulating unit 307 Second heat radiating unit 308 Second heat insulating unit 309 Chemical substance transport unit 310 Chemical substance detection unit 311 Second charged fine particle 312 Sample gas generating unit 401 Liquid droplet 402 Tailor cone

Claims (13)

A chemical substance concentration method using an electrostatic spraying device,
The electrostatic spraying device
A container,
A sample gas inlet communicating with the container;
A cooling part provided at one end of the container;
An atomizing electrode part provided at one end of the cooling part;
A counter electrode provided inside the container;
A chemical substance recovery unit provided at the other end of the container;
A dopant supply port communicating with the container;
The sample gas includes water vapor and a chemical substance,
Below the dew point temperature of the water vapor, the chemical substance is a substance that forms a condensate with the water vapor,
The dopant is a substance that dissolves in the condensate,
The electric affinity of the dopant is greater than the electron affinity of water,
The method
An injection step of injecting the sample gas into the container from the injection port;
A first condensate producing step of cooling the atomizing electrode part by the cooling part and turning the sample gas into a first condensate on the outer peripheral surface of the atomizing electrode part;
Supplying the dopant from the supply port to the container;
A dopant cooling step for cooling the dopant on the outer peripheral surface of the atomizing electrode portion;
A dissolution step of dissolving the dopant in the first condensate;
A charged fine particle forming step of applying a voltage between the atomizing electrode portion and the counter electrode portion to make the first condensate charged fine particles,
A chemical substance concentration method including a recovery step of applying a voltage between the counter electrode part and the chemical substance recovery part to recover the charged fine particles to the chemical substance recovery part.   2. The chemical substance concentration method according to claim 1, wherein the dopant is a polar organic compound.   2. The chemical substance concentration method according to claim 1, wherein the dopant is an organic acid.   The method of claim 1, wherein the dopant is acetic acid.   The chemical substance concentration method according to claim 1, wherein the dopant is oxygen.   2. The chemical substance concentration method according to claim 1, wherein a concentration of the dopant in the first condensate is higher than a concentration of the chemical substance in the first condensate.   The chemical substance concentration method according to claim 1, wherein the container includes a barrier at a position where the sample gas collides.   The chemical substance concentration method according to claim 1, wherein the sample gas contains a polar organic solvent.   The chemical substance concentration method according to claim 1, wherein the chemical substance is a polar organic compound.   The chemical substance concentration method according to claim 1, wherein the chemical substance is a volatile organic compound.   The chemical substance concentration method according to claim 1, wherein the charged fine particles are heated by infrared light.   The chemical container concentration method according to claim 1, wherein the container includes an optical waveguide.   The chemical substance concentration method according to claim 1, wherein a chemical substance detection unit is provided in the electrostatic spraying device.