JP2013254752A - Liquid chromatograph mass spectrometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion source which allows for any of ESI ionization, APCI ionization, and ESI/APCI simultaneous ionization, and insufficient heating is not brought about even if the flow rate of a sample liquid is high.SOLUTION: The liquid chromatograph mass spectrometer includes a conductive spray nozzle 51 having a double tube structure and spraying a sample liquid by nebulizer gas from a spray port J, a cylindrical heater 55 surrounding the front space K of the spray port J cylindrically, a cylindrical electrode 56 surrounding the front space K of the spray port J cylindrically, and forming a potential difference for ESI between the spray nozzle 51, a first power supply 61 for applying a voltage between the spray nozzle 51 and the cylindrical electrode 56, a corona discharge needle 57 for an APCI located in front of the cylindrical electrode 56, and a second power supply 62 for applying a voltage to the corona discharge needle 57.

Description

  The present invention relates to an ion source of a liquid chromatograph mass spectrometer that performs mass spectrometry by ionizing an analyte molecule separated and eluted by a liquid chromatograph apparatus, and more particularly, atmospheric pressure chemical ionization (APCI) and The present invention relates to an ion source that performs ionization by electrospray ionization (ESI).

  A liquid chromatograph mass spectrometer (also referred to as LC / MS) is a liquid chromatograph (also referred to as an LC section) that separates and elutes a liquid sample for each component, and ionization that ionizes sample components eluted from the LC section. And a mass spectrometer (also referred to as an MS unit) that detects ions sent from the ionization chamber.

Some LC / MS ion sources use an atmospheric pressure ionization method.
FIG. 8 is a schematic configuration diagram illustrating an example of LC / MS using ESI which is one of atmospheric pressure ionization methods. In this LC / MS 101, an ionization chamber 11 that ionizes a liquid sample from the LC section under atmospheric pressure, a first intermediate chamber 12 adjacent to the ionization chamber 11, and a second intermediate chamber adjacent to the first intermediate chamber 12. 13 and a mass spectrometer (MS unit) 14 adjacent to the second intermediate chamber 13 are arranged so as to line up with a partition wall therebetween.

An ion source 15 having a spray nozzle (probe) 151 is attached to the ionization chamber 11. The spray nozzle 151 is supplied with a liquid sample whose components have been separated in the LC section through a flow path 155 and a nebulization gas (for example, dry nitrogen gas) through a flow path 156, and the liquid sample is mixed with the nebulization gas. It is sprayed as a mist.
FIG. 9 is an enlarged cross-sectional view of the tip portion of the spray nozzle 151. The spray nozzle 151 has a metal double tube structure, and a liquid sample from the flow path 155 is ejected from the inner tube 152. The nebulization gas in the flow path 156 is injected from the outer tube 153. The distal end of the inner tube 152 protrudes by about 2 mm from the distal end of the outer tube 153, and the liquid sample ejected from the inner tube 152 becomes a mist state due to the collision action with the nebulizing gas ejected to the surroundings. Sprayed.

  Further, the spray nozzle 151 is connected to a power supply 161 for applying a high voltage, and a high voltage of several kV is applied to the tip of the spray nozzle 151. By spraying the liquid sample in a state where a high voltage is applied, ionized microdroplets are generated.

A heater block 20 having a built-in temperature control mechanism is fixed to a partition wall that partitions the ionization chamber 11 and the first intermediate chamber 12. Further, a small-diameter and circular tubular desolvation tube 19 is formed so as to penetrate the heater block 20. Thereby, the ionization chamber 11 and the first intermediate chamber 12 communicate with each other via the desolvation tube 19. The desolvation tube 19 has a function of promoting desolvation and ionization by heating action and collision action when ions sprayed by the spray nozzle 151 and fine sample droplets pass. Note that the desolvation tube 19 plays a role for desolvation not only by ionization by ESI but also by APCI described later.
The inlet of the desolvation tube 19 is directed in a direction substantially perpendicular to the sample spray direction from the spray nozzle 151 so that the sprayed huge sample droplet does not jump into the desolvation tube 19 as it is. A drain 30 is formed in front of the spraying direction of the sample droplet from the spray nozzle 151, and unnecessary sample droplets are discharged from the drain 30 to the outside.

  A first ion lens 21 is provided inside the first intermediate chamber 12, and an exhaust port 31 for evacuating with an oil rotary pump (RP) is provided on the lower surface of the first intermediate chamber 12. A skimmer 22 having a pore (orifice) is formed in a partition wall between the first intermediate chamber 12 and the second intermediate chamber 13, and the inside of the first intermediate chamber 12 and the second intermediate chamber are interposed through the pore. 13 communicates with the inside.

  An octopole 23 and a focus lens 24 are provided in the second intermediate chamber 13, and an exhaust port 32 for evacuating by a turbo molecular pump (TMP) is provided on the lower surface of the second intermediate chamber 13. It has been. The partition wall between the second intermediate chamber 13 and the mass spectrometer 14 is provided with an inlet lens 25 having a pore, and the inside of the second intermediate chamber 13 and the inside of the mass spectrometer 14 are connected through the pore. Communicate.

A first quadrupole 16, a second quadrupole 17, and a detector 18 are provided inside the mass spectrometer 14, and the lower surface of the mass spectrometer 14 is vacuumed by a turbo molecular pump (TMP). An exhaust port 33 for exhausting is provided.
The ion lens 21, the octopole 23, the focus lens 24, and the entrance lens 25 efficiently send ions that pass under the respective ion velocities to the next stage under respective vacuum conditions. Has a convergence effect.

  In such an LC / MS 101, ions generated by ESI in the ionization chamber 11 are removed from the desolvation tube 19, the first ion lens 21 in the first intermediate chamber 12, the skimmer 22, and the octopole in the second intermediate chamber 13. 23, the focus lens 24, and the entrance lens 25 are sequentially sent to the mass spectrometer 14. Unnecessary ions are discharged by the quadrupoles 16 and 17, and only specific ions reaching the detector 18 are detected.

In addition to the electrospray ionization method (ESI) described above, ionization by atmospheric pressure chemical ionization method (APCI) is also widely used.
Here, the difference between ESI and APCI will be described. As described above, ESI sprays the liquid sample eluted from the LC section together with the nebulization gas from the tip of the spray nozzle. A high voltage is applied to the spray nozzle, and the liquid sample is sprayed as charged droplets into the ion chamber under atmospheric pressure by a strong electric field generated at the tip of the nozzle. The sprayed charged droplets are analyzed by evaporating the solvent by the drying gas in the ionization chamber, increasing the charge density of the charged droplets, and proceeding with droplet breakup due to repulsion due to the Coulomb force within the droplets. Ionization of the target component is promoted. This ionization method is suitable for ionizing a compound having high polarity.

  On the other hand, the APCI heats the tip portion (spray port) of the spray nozzle similar to ESI by providing a heater so as to cover the spray port in a cylindrical shape, or partitions the ionization chamber from the intermediate chamber. The sprayed sample droplet is heated to a high temperature (400 ° C. to 500 ° C.) by heating by the desolvation tube 19 that passes through the heater block (heater block 20 in FIG. 8) built in the partition wall, thereby causing the sample droplet to be heated. Promotes desolvation of. Then, in the region where the sprayed droplets exist, and near the entrance (ion introduction port) of the desolvation tube, buffer ions (solvent ions) are generated by generating corona discharge with an electrode needle, Ionization (chemical ionization) is performed by chemically reacting this with the component to be analyzed. This ionization method is suitable for ionizing a compound having low polarity.

  FIG. 10 is a schematic configuration diagram showing an LC / MS 102 in which the LC / MS 101 described in FIG. 8 is improved to enable ionization by APCI. The same components as those in FIG. In this LC / MS 102, a voltage is applied from a high voltage power source 162 to generate a corona discharge in a region where sample droplets sprayed from the spray nozzle 151 exist in the vicinity of the inlet of the desolvation tube 19 in the ionization chamber 11. The tip of the electrode needle 160 is arranged.

  As described above, since the analysis target component is ionized by different mechanisms in ESI and APCI, the ionization method is selected according to the characteristics such as the polarity of the analysis target.

  Depending on the analysis target, there are cases where a liquid sample containing unknown components is analyzed, or samples containing many types of components from components having low polarity to components having high polarity are desired to be analyzed at once. In order to perform such an analysis, an ion source that alternately switches APCI and ESI in a short cycle and an ion source that simultaneously executes APCI and ESI are also disclosed (Patent Document 1, Patent). Reference 2).

For example, in the multimode ion source described in Patent Document 1, as in FIG. 10, an electrospray probe (ESI ion source) and a corona discharge needle are housed in a chamber (ionization chamber) and supplied from a power source. Supplying a high voltage to either the electrospray probe, the corona discharge needle, or both.
In addition, in APCI, desolvation by heating and drying of a liquid sample is important. However, according to the multimode ionization source of Patent Document 2, in order to promote heating and drying of a charged aerosol, in addition to introducing a high temperature gas, The use of electromagnetic radiation such as infrared waves and microwaves is described.

JP 2005-528746 Gazette JP 2005-539358 Gazette

  As described above, the ionization method in which ESI ionization and APCI ionization are simultaneously used is used for analyzing a liquid sample containing an unknown component, or a sample containing many kinds of components from a low polarity component to a high polarity component. This is useful when you want to analyze

  By the way, in recent LC / MS, it is required to increase the throughput of the analysis time, and for that purpose, it is necessary to spray the eluate from the LC section while making the flow rate as high as possible. Specifically, a flow rate of about 0.2 ml / second for sending a liquid sample before is required to increase the flow rate to about 1 ml / second. In that case, there is a problem that the sample droplet is not sufficiently vaporized due to insufficient heating. That is, in the LC / MS 102 shown in FIG. 10, desolvation is performed by supplying heated nebulization gas or heating by the desolvation tube 19, but when the flow rate of the liquid sample is increased, these alone are insufficiently heated, In particular, ionization of a low-polarity compound by APCI will cause insufficient heating.

  For this reason, it is also disclosed that an infrared heater is provided in the ionization chamber 11 for the purpose of assisting heating to heat a wide space in the ionization chamber, but it is still difficult to eliminate insufficient heating when the flow rate of the eluate increases. In addition, in order to increase the temperature of the wide space of the ionization chamber, it was necessary to use an ionization chamber having heat resistance (APCI is vaporized and desolvated by heating at about 400 ° C.).

Therefore, the present invention can perform any of ESI ionization, APCI ionization, and ESI / APCI simultaneous ionization, and can efficiently heat the sprayed sample droplet, and can perform APCI ionization (and ESI / APCI simultaneous). An object of the present invention is to provide an ion source having a new structure in which insufficient heating is not a problem even in the case of ionization.
In addition, the present invention can locally perform heating necessary for APCI ionization without providing a heating mechanism for heating a wide space of the ionization chamber such as an infrared heater in the ionization chamber, and yet, ESI ionization as in the prior art. It is an object to provide an ion source that is also possible.

  An ion source according to the present invention, which has been made to solve the above problems, is an ion source for a liquid chromatograph mass spectrometer that ionizes a liquid sample sent from a liquid chromatograph unit and sends the sample to a mass analyzer, An electrically conductive spray nozzle that sprays the sample liquid from the spray port with the nebulization gas, and a front space of the spray port. A cylindrical heater that surrounds the cylinder and passes the sample droplet sprayed from the spray port while heating, and is provided to surround the front space of the spray port in a cylindrical shape and to be separated from the spray nozzle, A cylindrical electrode that forms a potential difference with the spray nozzle during ionization by means of ionization, and a voltage for ionization by ESI is applied between the spray nozzle and the cylindrical electrode A first power source, a corona discharge needle disposed in front of the cylindrical electrode, to which a voltage for corona discharge is applied during ionization by APCI, and a voltage for ionization by APCI applied to the corona discharge needle A second power source is provided.

That is, the ion source according to the present invention includes a first power source for ESI and a second power source for APCI. A high voltage is applied from the first power source to perform ionization by ESI, and a high voltage is applied from the second power source to APCI. Perform ionization. A high voltage may be applied only to ESI (ESI ionization), or a high voltage may be applied only to APCI (APCI ionization). Moreover, you may apply a high voltage to both simultaneously (simultaneous ionization). The first power source and the second power source may be shared as long as high voltages for ESI and APCI can be applied independently.
During ionization by ESI (including simultaneous ionization), a high voltage is applied between the spray nozzle and the cylindrical electrode by the first power source. As a result, a space with a large potential difference can be formed around the spray port, and ionization by ESI becomes possible.
During ionization by APCI (including simultaneous ionization), a high voltage is applied to the corona discharge needle by the second power source. Thereby, the sample droplet heated inside the cylindrical heater is sprayed while being desolvated, and ionization (chemical ionization) is performed by a chemical reaction with buffer ions (solvent ions) generated by corona discharge. At this time, the sample droplets (including ions) that pass through the inside of the cylindrical heater can be efficiently heated to a high temperature in the cylindrical body, so even if the flow velocity of the supplied sample droplets is increased However, ionization by APCI can be performed without any problem.

In the above invention, it is preferable that the first power source applies a voltage to the spray nozzle and makes the cylindrical electrode a ground potential.
Since ionization is possible as long as a potential difference necessary for ionization is relatively applied between the spray nozzle and the cylindrical electrode, the first power source may be connected to the spray nozzle side, or to the cylindrical electrode side. You may connect. However, a stable high voltage can be applied by applying a voltage to the spray nozzle side and a ground potential on the cylindrical electrode side, and a high voltage can be applied independently from two power sources during simultaneous ionization. Control can be easily performed.

  In the above invention, the separation distance between the spray nozzle and the cylindrical electrode is preferably 2 mm to 30 mm. As a result, a potential difference necessary and sufficient for ionization can be formed in the front space of the spray nozzle (in the cylindrical heater).

In the said invention, it is preferable to make the internal diameter of the said cylindrical electrode larger than the internal diameter of the said spray nozzle outer tube | pipe.
As a result, the sample droplet sprayed from the spray nozzle can be surely passed through the cylindrical electrode and is not subjected to fluid resistance (pipe resistance) due to the cylindrical electrode. The sample droplet can be sprayed.

As described above, according to the LC / MS of the present invention, the sample droplet sprayed from the spray port of the spray nozzle can be locally and efficiently heated at a high temperature in the cylindrical heater. Since a large potential difference can be generated in the electrode, stable and reliable ionization can be achieved by any of ESI ionization, APCI ionization, and ESI / APCI simultaneous ionization methods. Also, in the case of APCI ionization (and ESI / APCI simultaneous ionization), insufficient heating is not a problem.
In addition, since the heating mechanism for heating the entire space of the ionization chamber such as an infrared heater is not provided in the ionization chamber, it is not necessary to heat the wide space of the ionization chamber, so that the entire ionization chamber can withstand high temperature heating. There is no need to

The schematic block diagram which shows the liquid chromatograph mass spectrometer (LC / MS) using an example of the ion source which concerns on this invention. The schematic block diagram of the ion source of FIG. The figure which looked at the ion source of FIG. 2 from the front of the cylindrical heater. The schematic block diagram which shows 2nd embodiment of an ion source. The figure which looked at the ion source of FIG. 4 from the front of the cylindrical heater. The schematic block diagram which shows 3rd embodiment of an ion source. The figure which looked at the ion source of FIG. 6 from the front of the cylindrical heater. The schematic block diagram which shows the prior art example of LC / MS using ESI. The expanded sectional view of the front-end | tip part in the spray nozzle for ESI. The schematic block diagram which shows the prior art example of LC / MS which added the improvement for ionizing by APCI with ESI.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram showing an LC / MS 103 using an example of an ion source according to the present invention, and FIG. 2 is a schematic configuration diagram of the ion source of FIG. 3 is a view of the ion source of FIG. 2 as viewed from the front (spray side) of a cylindrical heater 55 described later. Since the first intermediate chamber 12, the second intermediate chamber 13, and the mass spectrometer (MS unit) 14 in the LC / MS 103 have the same structure as the conventional example described in FIG. To do.

An ion source 50 is attached to the ionization chamber 11 of the LC / MS 103. The ion source 50 mainly includes a spray nozzle 51, a ceramic tube 54, a cylindrical heater 55, a cylindrical electrode 56, a corona discharge needle 57, a first power supply 61, and a second power supply 62.
The spray nozzle 51 is supplied with a liquid sample whose components have been separated in the LC section via a flow path 155 and also supplied with a dry nebulization gas (for example, dry nitrogen gas) via a flow path 156. The nebulization gas is supplied in a state heated to a high temperature by a heating mechanism (not shown).

  The spray nozzle 51 has a metal double circular tube structure composed of an inner tube 52 and an outer tube 53, and is supported by a flange 71 via an insulating material (not shown). The inner pipe 52 is connected to the flow path 155 so that the liquid sample flows, and the outer pipe 53 is connected to the flow path 156 so that the nebulization gas flows. The tip of the inner tube 52 protrudes from the tip of the outer tube 53 by about 2 mm to 10 mm, and the liquid sample ejected from the inner tube 52 collides with the nebulization gas ejected from the outer tube 53 (and It is sprayed in a mist state due to the thermal action of the heated dry gas).

  The inner tube 52 of the spray nozzle 51 is electrically connected to a first power supply 61 (HV1) for applying high voltage for ESI, and a high voltage of several kV (switchable between positive and negative polarity) is sprayed. It can be applied to the tip of the nozzle 51. As a result, the sample droplet is sprayed in a state where a large potential difference is generated between the tip of the spray nozzle 51 and the cylindrical electrode 56 separated by a distance of 5 mm to 30 mm, so that ionization by ESI is performed. Fine droplets containing (mainly ions of highly polar compounds) are sprayed.

  The ceramic tube 54 is supported at the base end by the flange 71 and surrounds the spray port (open end) J of the spray nozzle 51 and is attached so as to surround the front space K of the spray port J in a cylindrical shape. As a result, the sample droplet sprayed from the spray port J flows reliably toward the front space K without spreading in the lateral direction.

  A cylindrical heater (electric heater) 55 is wound around the outer circumference of the ceramic tube 54 corresponding to the area of the front space K. The heating temperature is monitored by a temperature sensor 58 in contact with the ceramic tube 54, and a temperature controller. The temperature of the front space K can be controlled to a desired temperature by performing the feedback control by the above. For example, the temperature is controlled between 400 ° C. and 500 ° C. during ionization by APCI, and between 250 ° C. and 400 ° C. during simultaneous ionization.

  The cylindrical electrode 56 is fixed to the inner wall of the ceramic tube 54 so as to surround the area of the front space K, and is grounded so as to have a ground potential. The cylindrical electrode 56 and the tip of the spray nozzle 51 (tip of the inner tube 52) are separated by about 2 mm to 30 mm, and when a high voltage is applied from the first power supply 61, a large potential difference is generated in this gap. Thus, ESI ionization can be performed.

  The inner diameter of the front space K (the inner diameter of the cylindrical electrode 56) is larger than the inner diameter of the outer tube 53 of the spray nozzle 51. Therefore, the sprayed sample droplet is not condensed in the front space K, and Since it is sprayed without receiving fluid resistance due to the piping when passing, the vaporization of sample droplets and the promotion of desolvation can be surely performed.

The corona discharge needle 57 is arranged in a space L near the opening end M of the cylindrical electrode 56 so that the tip of the needle is in contact with the sample droplet flowing out from the opening end M.
The corona discharge needle 57 is electrically connected to a second power supply 62 (HV2) for high voltage application for APCI, and can apply a high voltage of several kV (switchable between positive and negative polarity). . Thus, by generating corona discharge, buffer ions (solvent ions) are generated and chemically reacted with the sample droplets so that ionization (chemical ionization) by APCI can be performed. In this way, fine droplets containing ions (mainly ions of low polar compounds) are sprayed.

Next, the ionization operation by the ion source 50 will be described.
In the case of performing ionization by ESI (including the case of performing ESI / APCI simultaneous ionization), a liquid sample and a nebulization gas are supplied in a state where a high voltage of 2 to 3 kV is applied from the first power supply 61. The sample droplet is sprayed from the spray port J of the spray nozzle 51 and passes through a region where a large potential difference is generated with the cylindrical electrode 56, whereby the sample droplet is ionized by ESI and passes through the front space K. To pass. At this time, when ionization by APCI is not performed at the same time, the temperature of the front space K may be heated to about 250 ° C. When ionization by APCI is performed at the same time, it is heated to about 400 ° C.

  Moreover, when ionizing by APCI (including the case of performing ESI / APCI simultaneous ionization), a high voltage of 2 to 3 kV is applied from the second power source 62 and the front space K is heated to about 400 ° C., Supply liquid sample and nebulization gas. When the sample droplet is sprayed from the spray port J, vaporization and desolvation are promoted in the front space K heated at a high temperature, and the sample droplet and ESI ions flow out to the outside of the open end M. . A corona discharge is generated by a corona discharge needle 57 to which a high voltage is applied, thereby generating buffer ions (solvent ions), which are ionized (chemically reacted) with a chemical target component of the sample droplet that has flowed out. Ionization).

  As described above, in any of ESI ionization, APCI ionization, and ESI / APCI simultaneous ionization, the region where the sample droplets and ions are localized (front space K) is selectively concentrated to efficiently heat at a high temperature. Thus, even when the flow rate of the sample liquid eluted from the LC section is large, heating sufficient for ionization is performed.

(Embodiment 2)
FIG. 4 is a schematic configuration diagram of an ion source 50a according to the second embodiment of the present invention. FIG. 5 is a view of the ion source 50a of FIG. 4 as viewed from the front (spray side) of the cylindrical heater 55a. About the same structure as FIGS. 1-3, description is abbreviate | omitted by attaching | subjecting a same sign.
In this embodiment, the ceramic tube 54a surrounds the spray port J. However, the front space K is not a ceramic tube 54a but a cylindrical shape made of a conductor tube (metal tube) fixedly supported at the tip of the ceramic tube 54a. It is made to surround with the electrode 56a. A cylindrical heater 55a is wound around the outer periphery of the cylindrical electrode 56a.
In the second embodiment, the heat of the cylindrical heater 55a is directly transmitted to the cylindrical electrode 56a without passing through the ceramic tube, so that the thermal responsiveness of the front space K can be improved as compared with the first embodiment.

(Embodiment 3)
FIG. 6 is a schematic configuration diagram of an ion source 50b according to the third embodiment of the present invention. FIG. 7 is a view of the ion source 50b of FIG. 6 as viewed from the front (spray side) of the cylindrical heater 55b. About the same structure as FIGS. 1-3, description is abbreviate | omitted by attaching | subjecting a same sign.
In this embodiment, a conductor tube (metal tube) 54b surrounding the spray hole J and the front space K is used instead of the ceramic tubes 54 and 54a of FIGS. The conductor tube 54b is grounded and has the same function as the case where the tubular electrode 56 of FIG. 2 is grounded as a tubular ground electrode. A spacer (not shown) made of an insulating material is inserted into the gap between the conductor tube 54b and the spray nozzle 51 to prevent a short circuit. A cylindrical heater 55b is wound around the outer periphery of the conductor tube 54b.
Also in the third embodiment, since the heat of the cylindrical heater 55b is directly transmitted to the conductor tube 54b without passing through the ceramic tube, the thermal responsiveness of the front space K can be improved as compared with the first embodiment.

  The present invention can be used for an ion source of a liquid chromatograph mass spectrometer (LC / MS).

11: Ionization chamber 50, 50a, 50b: Ion source 51: Spray nozzle 52: Inner tube 53: Outer tube 54, 54a: Ceramic tube 54b: Conductor tube (also used as cylindrical electrode)
55, 55a, 55b: cylindrical heater 56, 56a: cylindrical electrode 57: corona discharge needle 61: first power supply (for ESI)
62: Second power supply (for APCI)
J: Spray port K: Front space M: Open end L: Space near open end

Claims (7)

An ion source for a liquid chromatograph mass spectrometer that ionizes a liquid sample sent from a liquid chromatograph and sends it to a mass spectrometer,
A conductive spray nozzle having a double tube structure of an inner tube to which a sample liquid is supplied and an outer tube to which a nebulization gas is supplied, and spraying the sample liquid from the spray port by the nebulization gas;
A cylindrical heater that surrounds the front space of the spray port in a cylindrical shape, and allows a sample droplet sprayed from the spray port to pass while heating;
A cylindrical electrode that surrounds the front space of the spray port in a cylindrical shape and is spaced apart from the spray nozzle, and forms a potential difference with the spray nozzle when ionized by ESI;
A first power source for applying a voltage for ionization by ESI between the spray nozzle and the cylindrical electrode;
A corona discharge needle disposed in front of the cylindrical electrode, to which a voltage for corona discharge is applied at the time of ionization by APCI;
An ion source comprising: a second power source that applies a voltage for ionization by APCI to the corona discharge needle. An ion source for a liquid chromatograph mass spectrometer that ionizes a liquid sample sent from a liquid chromatograph and sends it to a mass spectrometer,
A conductive spray nozzle having a double tube structure of an inner tube to which a sample liquid is supplied and an outer tube to which a nebulization gas is supplied, and spraying the sample liquid from the spray port by the nebulization gas;
A ceramic tube attached so as to surround the spray port and a front space of the spray port in a cylindrical shape;
A cylindrical heater that is attached to the outer peripheral surface of the ceramic tube so as to surround the front space of the spray port in a cylindrical shape, and allows the sprayed sample droplets to pass while heating,
A cylindrical electrode that surrounds the front space of the spray port in the ceramic tube in a cylindrical shape, is provided so as to be separated from the spray nozzle, and forms a potential difference with the spray nozzle at the time of ionization by ESI;
A first power source for applying a voltage for ionization by ESI between the spray nozzle and the cylindrical electrode;
A corona discharge needle disposed in front of the cylindrical electrode, to which a voltage for corona discharge is applied at the time of ionization by APCI;
An ion source comprising: a second power source that applies a voltage for ionization by APCI to the corona discharge needle. An ion source for a liquid chromatograph mass spectrometer that ionizes a liquid sample sent from a liquid chromatograph and sends it to a mass spectrometer,
A conductive spray nozzle having a double tube structure of an inner tube to which a sample liquid is supplied and an outer tube to which a nebulization gas is supplied, and spraying the sample liquid from the spray port by the nebulization gas;
A ceramic tube attached so as to surround the spray port of the spray nozzle in a cylindrical shape;
A cylindrical heater that is supported by the ceramic tube, is attached so as to surround a space in front of the spray port of the spray nozzle, and passes the sprayed sample droplet while heating;
A cylindrical electrode that surrounds the front space inside the cylindrical heater and is spaced apart from the spray nozzle, and forms a potential difference with the spray nozzle when ionized by ESI;
A first power source for applying a voltage for ionization by ESI between the spray nozzle and the cylindrical electrode;
A corona discharge needle disposed in front of the cylindrical electrode, to which a voltage for corona discharge is applied at the time of ionization by APCI;
An ion source comprising: a second power source that applies a voltage for ionization by APCI to the corona discharge needle. An ion source for a liquid chromatograph mass spectrometer that ionizes a liquid sample sent from a liquid chromatograph and sends it to a mass spectrometer,
A conductive spray nozzle having a double tube structure of an inner tube to which a sample liquid is supplied and an outer tube to which a nebulization gas is supplied, and spraying the sample liquid from the spray port by the nebulization gas;
A conductor tube which is attached so as to surround the spray port and a space in front of the spray port in a cylindrical shape, is provided so as to be separated from the spray nozzle, and is used as a cylindrical electrode when ionized by ESI by being grounded When,
A cylindrical heater attached to the outer peripheral surface of the conductor tube so as to surround the front space of the spray port in a cylindrical shape, and allowing the sprayed sample droplets to pass while heating;
A first power source for applying a voltage for ionization by ESI to the spray nozzle;
A corona discharge needle disposed in front of the cylindrical electrode, to which a voltage for corona discharge is applied at the time of ionization by APCI;
An ion source comprising: a second power source that applies a voltage for ionization by APCI to the corona discharge needle. The ion source according to any one of claims 1 to 3, wherein the first power source applies a voltage to the spray nozzle and sets the cylindrical electrode to a ground potential. The ion source according to any one of claims 1 to 5, wherein a separation distance between the spray nozzle and the cylindrical electrode is 2 mm to 30 mm. The ion source according to claim 1, wherein an inner diameter of the cylindrical electrode is larger than an inner diameter of the spray nozzle outer tube.

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