JP3912688B1 - Organic compound measuring apparatus and measuring method thereof - Google Patents

Abstract

An object of the present invention is to provide an organic compound measuring apparatus and an organic compound measuring method for measuring an organic compound, particularly a trace volatile organic compound in the atmosphere, simultaneously with multiple components with high sensitivity and in real time.
In order to solve the above problems, the present invention provides a proton transfer reaction time-of-flight mass spectrometer comprising a discharge ion source, a drift tube, a transport chamber, a beam shaping transport member, and a time-of-flight mass spectrometer. The ion source comprises an extrusion electrode, a first spacer, an extraction electrode, a second spacer, and a connection electrode having a perforation in the center. The extrusion electrode, the first spacer, and the extraction electrode The structure of the organic compound measuring apparatus characterized in that discharge is performed at the extrusion electrode and the extraction electrode in the ion generation space formed by the step of converting the water vapor into H ₃ O ⁺ and the measurement of the organic compound using the apparatus It was a method.
[Selection] Figure 1

Description

  The present invention relates to an organic compound measuring apparatus and an organic compound measuring method for measuring an organic compound, in particular, a minute amount of a volatile organic compound in the atmosphere at the same time with high sensitivity and in real time.

Volatile organic compounds and (V olatile O rganic C ompound) is sometimes referred to as VOC, paraffins, olefins, there are the aromatic hydrocarbons.

  As an apparatus for measuring volatile organic compounds in the atmosphere, (1) a gas chromatograph that uses a chromatograph to separate organic compounds and detect them with a flame ionization detector or an electron impact ionization quadrupole mass spectrometer ( GC-FID, GC-MS) are commercially available.

  However, (1) detection of organic compounds using gas chromatographs requires time for pretreatment and separation, so measurement in real time is difficult, and some organic compounds have high reactivity. There is a possibility that organic compounds may be altered during pretreatment (concentration, etc.).

(2) Using H ₃ O ⁺ generated by water discharge as a reagent ion, a proton is added to an organic compound by a proton transfer reaction, and the RH ⁺ generated in the drift tube is converted into a quadrupole mass spectrometer (QMS). A proton transfer reaction mass spectrometer (PTR-MS) that separates each mass by applying an electric field is also commercially available. The electric field fluctuates with time, and only an arbitrary mass component reaches the detector (SEM).

Here, the proton transfer reaction (Proton-Transfer-Reaction) is
This reaction is represented by the following formula 1.
R + H ₃ O ⁺ → RH ⁺ + H ₂ O Formula 1
R is the VOC to be measured.

  Since PTR-MS uses a soft proton transfer reaction, VOC can be detected without being broken in the drift tube, and VOC can be selectively quantified without using a gas chromatograph. . In addition, since measurement with a relatively high time resolution is possible, it is possible to observe near the source (urban area) where the concentration fluctuation is severe.

  However, although (2) a commercially available PTR-MS is a highly sensitive device capable of detecting an organic compound at a sub ppbv concentration level, it cannot detect multiple components simultaneously because it uses a quadrupole mass filter.

  (3) As shown in FIG. 23 (FIG. 1 of Non-Patent Document 1), a proton transfer reaction time-of-flight mass spectrometer using a time-of-flight mass spectrometer 39 as a mass spectrometer in PTR-MS ( PTR-TOFMS) is being developed.

The proton transfer reaction time-of-flight mass spectrometer 29 described in Non-Patent Document 1 is a time-of-flight mass spectrometer 33 in which an ion source that generates H ₃ O ⁺ using a radiation source 30 and a drift tube 31 are provided with a reflectron 33c. Is attached. The drift tube 31 includes an electrode 31a and a spacer 31b that is an insulator.

Volatile organic compounds in the sample are water vapor introduced from the water vapor introduction port 30a, hydronium ions (H ₃ O ⁺ ) generated by an ion source using the radiation source 30, and a sample introduced from the sample introduction port 31c. (Outside air) collides in the drift tube 31 and causes the proton transfer reaction of the above formula 1 to become RH ⁺ , enters the transport chamber 32, and is transported to the ion acceleration chamber 33a while being shaped by the ion lens 32a.

The RH ⁺ is applied with a high-voltage pulse from the pulse extraction electrode 33f in the ion acceleration chamber 33a, the direction is changed, and the beam flight trajectory is corrected again by the trajectory correcting unit 33g, so that the time-of-flight mass It flies in the flight chamber 33b of the analyzer 33 at a speed different from the mass of the organic compound, the trajectory is bent by the electric field of the reflectron 33c, and is detected by the MCP detector 33d (microchannel plate).

The method for measuring the concentration of an organic compound by the proton transfer reaction time-of-flight mass spectrometer 29 described in Non-Patent Document 1 starts from the moment when a high voltage is applied to the pulse extraction electrode 33f of the signal of the organic compound that has reached the MCP detector 33d. Is stored in the time converter 33e, and this is repeated to obtain a mass spectrum of the organic compound in the sample containing the multi-component organic compound. The radiation source 30 uses ²⁴¹ Am alpha rays (44 MBq).

However, since the proton transfer reaction time-of-flight mass spectrometer 29 described in Non-Patent Document 1 uses the radiation source 30 for generating H ₃ O ⁺ , the proton transfer reaction time-of-flight mass spectrometer 29 cannot be taken out outdoors, and can be measured in the field in real time. There is a disadvantage that it cannot be performed and the sensitivity is two orders of magnitude lower than that of a commercially available PTR-MS using discharge.
R. S. Blake, et al, Anal. Chem. 3841-3845 (2004) 76.

  Furthermore, as shown in FIG. 24 (FIG. 1 of Non-Patent Document 2), the ion source that irradiates the radiation source 30 of Non-Patent Document 1 is replaced with an ion source 35 that uses discharge, and can be easily carried around. A holocathode discharge proton transfer reaction time-of-flight mass spectrometer 34 in which a discharge type proton transfer reaction vessel is attached to a time-of-flight mass spectrometer 39 with a reflectron 39c is being developed.

  Further, the structure is such that an aluminum drift tube 37 is attached to an R500 time-of-flight mass spectrometer (KORE Technologies, Ely, UK). A holocathode discharge ion source 35, a source drift tube 36, a drift tube 37, It consists of a transport chamber 38 with an ion lens 38a inside and a time-of-flight mass spectrometer 39 with a reflectron 39c.

  The discharge-type proton transfer reaction time-of-flight mass spectrometer 34 can be placed in a 1 m × 2 m space, weighs ˜300 kg, and requires an average power of 3.4 kW. The main hydronium ions are generated by a holocathode 35a made of tungsten having a water vapor inlet 35b, and the generation of hydronium ions reaches the maximum by the ion-molecule reaction with water in the next source drift tube 36. . The holocathode 35a and the source drift tube 36 constitute an ion source 35.

  The ions are sent to the drift tube 37. The drift tube 37 is formed by stacking four aluminum ring electrodes 37a having an inner diameter of 50 mm, and thin ring lenses are attached to the upper and lower ends thereof. The total length of the drift tube 37 is about 75 mm. The drift tube 37 is sandwiched between an entrance orifice (small hole) of 1 mm and an exit orifice of 500 μm.

  In the drift tube 37, a proton transfer reaction occurs between the hydronium ion and the analyte fed from the sample introduction port 36a capable of proton transfer. The ions pass through the exit orifice and are transported to the pulse extraction electrode 39f by the transport chamber 38 in the differential exhaust region by the first pump 38b and the second pump 39h in the first stage. Ions are extracted vertically in a pulse manner by the pulse extraction electrode 39f.

The time-of-flight mass spectrometer 39 is provided with an ion mirror of a reflectron 39c, and a pressure of 10 ⁻⁷ mbar is maintained using a 100 L ⁻¹ turbo molecular pump 39h. Ion detection uses an MCP detector 39d. The pressure in the drift tube 37 is 0.6 to 1.0 mbar, and the voltage between the entrance and exit orifices is 240V.

  The pulsar box 39e is an introduction terminal including a pulse switch for applying a voltage applied to the pulse extraction electrode 39f in a pulsed manner. In addition, the ion acceleration chamber 39a, the flight chamber 39b, and the trajectory correction unit 39g are the same as in Non-Patent Document 1.

According to the above-described holocathode discharge type proton transfer reaction time-of-flight mass spectrometer 34, it is possible to detect a trace gas component having a low concentration of about lppbv on a time scale of about 10 to 60 seconds. ₃ O ⁺ intensities normalized by the 1 × ¹⁰ 6 cps) detection sensitivity, 3.7ncps ppbv ^-1 toluene was 28ncps ppbv ^-1 with acetone.

  In addition, it has high mass resolution and high mass number accuracy (up to 300 ppm), enables acquisition of multi-component mass spectra, and enables rapid and selective online analysis of trace components in complex gas mixtures. .

Therefore, since no radiation is used, air sampled from the environment can be measured at the sampling site without being measured at a special indoor facility.
C. J. et al. Ennis, et al, Int. J. et al. Mass. Spectrom. 72-80 (2005) 247.

However, the invention described in Non-Patent Document 2 has a sensitivity that is one order of magnitude lower than that of commercially available PTR-MS, and more NO ⁺ and O ₂ ⁺ are generated due to the sample gas. It is not possible to measure low concentrations of volatile organic compounds.

  First, there is a problem with the structure of the ion source 35. Second, the passing distance of the transport chamber 4 is long. Third, due to the structure, the pressure in the drift tube 37 cannot be increased.

  Accordingly, the present invention provides an organic compound measuring apparatus and an organic compound measuring method for solving the above-described problems and measuring organic compounds, particularly trace volatile organic compounds in the atmosphere, in a multi-component manner with high sensitivity and in real time. It is intended.

In order to solve the above-mentioned problems, the present invention firstly provides a proton transfer reaction flight comprising a discharge ion source 2, a drift tube 3, a transport chamber 4, a beam shaping transport member 6, and a time-of-flight mass spectrometer 5. In the time-type mass spectrometer, the ion source 2 includes an extruded electrode 9 having a water vapor inlet 2a, a first spacer 11 which is an insulator disposed next to the extruded electrode 9, and the first spacer 11 Next, an extraction electrode 10 in which a perforation 10a is formed at the center of a convex portion 10b that is arranged and protrudes in the direction of the extrusion electrode 9, and a second spacer 11d that is an insulator arranged next to the extraction electrode 10; The connecting electrode 12 is arranged next to the second spacer 11d and has a mortar-shaped cut portion 12e on the back surface, and a perforation 12a is formed in the center. The extruded electrode 9 and the first spacer Discharged over 11 and the pusher electrode 9 of the ion generating space 22 formed by the extraction electrode 10 by the convex portion 10b of the lead electrodes 10, the measurement of an organic compound, characterized in that the water vapor H ₃ O ⁺ The apparatus was configured.

  Second, the perforation 10a drilled in the extraction electrode 10 has a diameter of 0.5 mm to 2 mm, third, the inner angle of the apex of the cone 6a is 90 ° or less, and fourth, the drift tube from the apex of the cone 6a. The distance to the orifice 20a of the disk 20 set in the recess 19f of the flange 19 constituting 3 is 5 mm to 15 mm or less, and fifthly, an organic compound measuring device is configured to apply a voltage to the cone 6a.

Further, to discharge the injected steam, H ₃ and the ion source 2 which generates a O ^+, is connected to the ion source 2, the H ₃ O ⁺ and the sample gas are reacted, drift tube 3 for generating the RH ⁺ A transport chamber 4 connected to the drift tube 3, a time-of-flight mass spectrometer 5 connected to the transport chamber 4, and an ion acceleration chamber 5a of the transport chamber 4 and the time-of-flight mass spectrometer 5. The organic compound measuring method is characterized in that it is composed of a beam-shaped transporting member 6 for partitioning the gas and is not exhausted by the ion source 2.

Since this invention is the above structure, the following effects are acquired. According to the present invention, since the backflow of the sample gas is suppressed in the ion generation space 22 and the discharge is stabilized, H ₃ O ⁺ can be generated at a high concentration, the proton transfer reaction occurs frequently in the drift tube 3, and RH ⁺ Can be introduced into the time-of-flight mass spectrometer 5 with high efficiency.

  Further, by adopting a differential exhaust system using the cone 6a from the disc orifice 20a at the outlet of the drift tube 3, ions generated in the drift tube 3 are efficiently introduced into the time-of-flight mass spectrometer 5. I was able to do that.

In addition, the ion generation space 22 is made compact, a resistance (1 MΩ) having an appropriate high resistance is attached between the three electrodes constituting the ion source 2, and a voltage is applied to the ion source 2 and the drift tube 3 with one power source. because be supplied, stable discharge and high H ₃ O ⁺ generation efficiency.

  Therefore, it is possible to measure a small amount of organic compound components such as in the low-concentration atmosphere in real time with a high sensitivity, and to take them out for field observation.

Incidentally, the H ₃ O ⁺ ion intensity is 6 × 10 ⁵ counts (corresponding to 1.7 × 10 ⁶ cps) integrated for 1 minute, and is detected (standardized at H ₃ O ⁺ intensity 1 × 10 ⁶ cps). sensitivity, 30ncps ppbv ^-1 propylene, 150ncps ppbv ^-1 acetaldehyde, 210ncps ppbv ^-1 with acetone, 50ncps ppbv ^-1 isoprene, 60ncps ppbv ^-1 benzene, 60ncps ppbv ^-1 with toluene, para - 50Ncps in xylene ppbv- ¹ . One-digit sensitivity is better than the invention of Non-Patent Document 2, and the sensitivity is comparable to that of commercially available PTR-MS.

An object of the present invention is to provide an apparatus for measuring an organic compound, particularly a minute amount of a volatile organic compound in the atmosphere at the same time, with high sensitivity and in real time, an apparatus for measuring an organic compound, and a method for measuring the organic compound. In a proton transfer reaction time-of-flight mass spectrometer comprising a source 2, a drift tube 3, a transport chamber 4, a beam shaping transport member 6, and a time-of-flight mass spectrometer 5, the ion source 2 is an extrusion having a water vapor inlet 2a. An electrode 9, a first spacer 11, which is an insulator disposed next to the extrusion electrode 9, and a perforation 10 a at the center of a protrusion 10 b that is disposed next to the first spacer 11 and protrudes toward the extrusion electrode 9. , A second spacer 11d that is an insulator disposed next to the extraction electrode 10, and a second spacer 11d next to the second spacer 11d. Ion generation formed of the connection electrode 12 which is arranged and has a mortar-shaped cut portion 12e on the back surface and which has a perforation 12a in the center, and is formed by the extrusion electrode 9, the first spacer 11 and the extraction electrode 10. This was realized by the configuration of the organic compound measuring device characterized in that discharge was performed at the extruding electrode 9 in the space 22 and the convex portion 10b of the extraction electrode 10 to change the water vapor to H ₃ O ⁺ .

  Below, based on an accompanying drawing, the measuring device of an organic compound and the measuring device of an organic compound which are the present invention are explained in detail.

  FIG. 1 is a schematic longitudinal sectional view of an organic compound measuring apparatus according to the present invention. The organic compound measuring apparatus 1 according to the present invention includes an ion source 2, a drift tube 3, a transport chamber 4, a beam shaping transport member 6, and a time-of-flight mass spectrometer 5. In FIG. 1, V1 to V6 represent applied voltages, and HV represents a high voltage.

In the method for measuring an organic compound using the organic compound measuring apparatus 1 according to the present invention, first, water vapor is inserted into the ion source 2 from the water vapor inlet 2a, a voltage of V1 is applied, and the ion source 2 uses H ₃ O ^+. The H ₃ O ⁺ is fed into the drift tube 3 and collides with the sample gas introduced from the sample introduction port 3a in the drift tube 3 to generate RH ⁺ as shown in the above formula 1.

  At this time, the organic compound measuring apparatus 1 controls the introduction rate of the water vapor and the injection rate of the sample gas so as to obtain a predetermined pressure while monitoring the pressure in the drift tube 3 with the pressure gauge 3 d connected to the drift tube 3. At the same time, neutral molecules in the drift tube 3 are exhausted by the first pump 3c.

  In order to reduce water molecules fed into the transport chamber 4, nitrogen gas is injected from the nitrogen inlet 3 b to the junction between the drift chamber 3 and the transport chamber 4, and the nitrogen gas flowing into the drift tube 3 is the first. It is removed together with neutral molecules by the pump 3c. Thereby, since interference of the signal of water cluster ion is removed, more ions derived from an organic compound can be detected. Instead of nitrogen gas, a rare gas such as helium or argon having low reactivity may be used.

On the other hand, in the holocathode discharge type proton transfer reaction time-of-flight mass spectrometer 34 described in Non-Patent Document 2, in order to prevent water molecules from entering the transport chamber 38, it corresponds to the position of the backflow prevention space 23 of the present invention. Excess water vapor is exhausted from the source drift tube 36 by a pump. As a result, the sample gas injected from the sample introduction port 36a flows backward to the source drift tube 36 and further flows backward to the ion source 35, and undesired NO ⁺ and O ₂ ⁺ are generated. FIG. As far as 6 is seen, O ₂ ⁺ is produced more than H ₃ O ⁺ , and NO ⁺ is also produced from 25% to 30% of H ₃ O ⁺ . Therefore, the H ₃ O ⁺ generation capability according to the present invention is remarkably high from here, and as a result, the measurement accuracy of the organic compound is also increased.

Next, the RH ⁺ passes through the transport chamber 4 for a short distance, passes through the beam shaping transport member 6, and is fed into the ion acceleration chamber 5a. Finally, the ion concentration is measured by the time-of-flight mass spectrometer 5.

  Here, the beam-shaping transport member 6 disposed in the transport chamber 4 cuts out ions that have passed through the transport chamber 4 by a perforation 6b drilled at the apex of the cone 6a, and is made up of three cylindrical electrodes. The ion beam is shaped by the lens 6z ′, the ion beam trajectory is corrected by the trajectory correcting unit 6o, and transported to the pulse extraction electrode 5g of the time-of-flight mass spectrometer 5. A voltage V4 (−60 V) is applied to the cone, a voltage V5 (+30 V) is applied to the central ion lens, and the other two ion lenses are grounded. It was not necessary to apply a voltage to the trajectory correction unit to correct the trajectory.

The time-of-flight mass spectrometer 5 applies a high voltage pulse to the RH ⁺ generated in the drift chamber 3, and corrects the trajectory of the pulse extraction electrode 5g and the RH ⁺ that causes the RH ⁺ to fly at a flight speed depending on its mass. An ion acceleration chamber 5a having a trajectory correcting unit 5e inside, a trajectory adjusting unit 5b having an ion lens 5h for converging the trajectory, a flight chamber 5c separated by the mass of RH ⁺ , and an MCP detector 5i It consists of the ion detection part 5d in. The flight resolution was about 50 cm, and the mass resolution (m / Δm) was about 100.

  In the organic compound measuring method using the organic compound measuring apparatus 1 according to the present invention, the differential exhaust system is driven. The differential evacuation system is a system in which the vacuum level of the time-of-flight mass spectrometer 5 cannot be rapidly increased in order to increase the vacuum level of the ion detector 5d, and thus the pressure is gradually reduced in the previous stage.

After the generation of RH ^{+, the} higher the degree of vacuum, the higher the residual rate of RH ^+. Therefore, the degree of vacuum is increased by the second pump 4 a and the third pump 4 b connected to the transport chamber 4. Therefore, two pumps were used here. This is because when gas molecules exist, they collide with RH ⁺ and RH ⁺ is lost. As a result, the measurement accuracy is lowered.

  For the same reason, it is necessary to increase the degree of vacuum stepwise by the fourth pump 5j connected to the ion acceleration chamber 5a and the fifth pump 5k connected to the flight chamber 5c.

In addition, the time-of-flight mass spectrometer 5 may be generally commercially available, and a reflectron may be attached. By attaching the reflectron, the flight speed of RH ⁺ can be corrected, and the flight distance of RH ⁺ is increased, so that the mass resolution (m / Δm) is improved.

  Hereinafter, the operating conditions in the present invention will be described. Ions that have passed through the transport chamber 4 are transported between the first and second of the pulse extraction electrodes 5g composed of three electrodes. A high voltage (HV) is applied in a pulse manner to the first and second electrodes, and ions are extracted toward the MCP detector 5i in a direction perpendicular to the traveling direction of the ion beam.

  Since it is necessary to apply a high voltage to the first and second electrodes at high speed, a transistor switch in the pulsar box 5f is used. A voltage of 5 kV and 4.5 kV is raised to the first and second electrodes, respectively, and a high voltage is applied for about 70 nsec for 1 μsec. The third electrode is always grounded.

  The ions extracted in the direction of the MCP detector 5i are subjected to ion beam trajectory correction by the trajectory correction unit 5e, and a voltage V6 (1.3 kV) is applied to the ion lens 5h in the trajectory adjustment unit 5b. Ions are detected by suppressing diffusion and colliding with the MCP detector 5i of the ion detector 5d. The MCP detector 5i is operated by applying a high voltage of -2 kV. It was not necessary to correct the ion beam trajectory by applying a voltage to the trajectory correcting plate of the trajectory correcting unit 5e.

  Since the ion flight distance is 50 cm and the ion velocity varies depending on the mass number of the ions, the lighter the mass number, the faster the pulse voltage is applied, and the heavier mass number of the ions travels in the flight chamber 5c. Then, it reaches the MCP detector 5i. Since it is necessary to detect ions at a high speed, the MCP detector 5i that rises and falls for 1 ns is used. The full width at half maximum of the mass spectrum of the organic compound measuring apparatus 1 according to the present invention was 19, 59, and 107, and was 0.35, 0.56, and 0.60, respectively.

  The timing at which a high voltage is applied to the pulse extraction electrode 5g is controlled by the first pulse generator 8a, and the high voltage switch is turned on / off at 10 kHz. The ion signal detected by the MCP detector 5i is stored by the time converter 7 synchronized with the first pulse generator 8a, and the time when the signal is detected from the on-time of the high voltage switch is stored. A histogram of the time and the vertical axis of the ion count is created. Since the arrival time of ions on the horizontal axis can be converted into the mass number of ions, this histogram corresponds to the mass spectrum.

  Such detection is integrated by repetition at 10 kHz. The second pulse generator 8b controls the start and end of this integration, and controls so as to perform integration for 60 seconds. The first pulse generator 8a and the second pulse generator 8b are controlled by the computer 8, and data obtained by the time converter 7 is input to the computer 8 and stored as a mass spectrum every 60 seconds.

FIG. 2 is a schematic cross-sectional view of an ion source, a drift tube, and a transport chamber. The discharge type ion source 2 is disposed after the extruded electrode 9 having the water vapor inlet 2a, the first spacer 11 which is an insulator disposed next to the extruded electrode 9, and the first spacer 11. It comprises an extraction electrode 10, a second spacer 11d which is an insulator disposed next to the extraction electrode 10, and a connection electrode 12 disposed next to the second spacer 11d. These three types of electrodes are involved in the discharge that generates H ₃ O ⁺ .

Electric discharge is generated in the ion generation space 22 formed by the extrusion electrode 9, the first spacer 11, and the extraction electrode 10, and the water vapor is changed to H ₃ O ⁺ . Water vapor is introduced from the water vapor introduction port 2a attached to the extrusion electrode 9 so as to be as symmetric as possible. The discharge mainly occurs in a narrow region of the extrusion electrode 9 and the extraction electrode 10, and H ₃ O ⁺ passes through the elongated perforation at the center of the extraction electrode 10, is formed into an ion beam, passes through the perforation of the connection electrode 12, and drift tube The proton transfer reaction space 24, which is within 3, is introduced.

The backflow prevention space 23 surrounded by the extraction electrode 10, the second spacer 11d, and the connection electrode prevents the sample gas from flowing back into the ion generation space 22, shapes the H ₃ O ⁺ beam, and adjusts the pressure. Have

  The pressure in the backflow prevention space 23 is kept slightly higher (about 5.1 Torr) than the pressure in the proton transfer reaction space 24 (about 5.0 Torr) in the drift tube 3, and the pressure in the ion generation space 22 is backflow. It is desirable to maintain a pressure (about 5.2) that is slightly higher than the pressure in the prevention space 23. As a result, the backflow of the sample gas into the ion generation space 22 can be extremely reduced.

When the sample gas flows back into the ion generation space 22, NO ⁺ , O ₂ ^{+ and the} like are generated, hindering generation of H ₃ O ⁺ , and antagonizing the proton transfer reaction with R in the drift tube 3, The production efficiency of RH ⁺ decreases. As a result, the measurement accuracy of the organic compound is lowered.

The drift tube 3 includes a sampler 13 for introducing a sample, a drift tube electrode 14 disposed next to the sampler 13, an insulating ring 15 disposed next to the drift tube electrode 14, and the insulating ring 15. Drift tube electrode 14e disposed next, insulating ring 15d disposed next to drift tube electrode 14e, drift tube electrode 14f disposed next to insulating ring 15d, and disposed next to drift tube electrode 14f The insulation ring 15e, the drift tube electrode 14g disposed in the insulation ring 15e, the first pump 3c for exhausting neutral molecules disposed next to the drift tube electrode 14g, and the pressure in the drift tube 3 are monitored. Insulation with tube connected to pressure gauge 3d 16, an inlet lens 17 for guiding an ion beam disposed next to the insulator with tube 16 to an orifice (small hole), a flange 19 connected to the transport chamber 4, the inlet lens 17 and the flange A spacer 18 with a conduit for passing nitrogen gas sandwiched between 19 and a disk 20 set in the flange 19 and having an orifice (small hole) through which RH ⁺ passes are formed.

  The ion beam emitted into the drift tube 3 collides with a sample gas containing an organic compound introduced from the sampler 13 and causes a proton transfer reaction in the proton transfer reaction space 24. The neutral gas is exhausted by the first pump 3 c downstream of the drift tube 3, and the ions pass through the inlet lens 17 and are transported to the high vacuum transport chamber 4.

  The pressure in the drift tube 3 was monitored with a pressure gauge 3d, and was maintained at 5 Torr. The breakdown is about 0.5 Torr of water vapor and about 4.5 oTorr of sample gas.

  Nitrogen gas can be introduced into the perforations 17a of the inlet lens 17, and is introduced as necessary to suppress the generation of cluster ions by water vapor. In addition, about 0.1 Torr is sufficient for the amount of nitrogen gas introduced.

The extrusion electrode 9, the extraction electrode 10, the connection electrode 12, and the drift tube electrodes 14, 14e, 14f, and 14g are provided with resistances R1 (1 MΩ), R2 (1 MΩ), and R3 (390 kΩ) between the electrodes. Is connected to V1 (5 kV direct current) having a resistance R4 (390Ω), and H ₃ O ⁺ or RH ⁺ is transported to the transport chamber 4 by an electric field.

The inlet lens 17 is connected to V2 (150 V) independently of the above system, and the flange 19 is connected to V3 (25 V). Moreover, since the loss of RH ⁺ ions can be further reduced by connecting V4 (−60 V) to the cone 6a, a voltage may be applied.

  The extrusion electrode 9, the extraction electrode 10, the connection electrode 11, the drift tube electrodes 14, 14e, 14f, and 14g, the inlet lens 17, the flange 19, and the cone 6a are conductors, and a voltage is applied thereto. Examples of the conductor include stainless steel and aluminum that are resistant to corrosion, but any material that is normally used as an electrode may be used. The disk 20 is made of stainless steel.

  The first spacer 11, the second spacer 11d, the sampler 13, the insulating rings 15, 15d, 15e, the insulator 16 with a tube, and the spacer 18 with a conduit are made of an insulating material having high antistatic properties, and are adjacent to each other. Insulate. For example, Nippon Polypenco Co., Ltd./Semitron (registered trademark), which is based on an insulating material reinforced poly Teflon (registered trademark) with high antistatic properties, is available.

  Each electrode and each insulator are sealed with an O-ring, and are fixed to the flange 19 by a column 3e and a column 3f. In addition, the support | pillar 3e and the support | pillar 3f coat | cover an insulating material to the insulator or the metal stick | rod.

  The column 3e is in the form of a single rod, penetrates through holes provided in each electrode, and is screwed at the lower end to the upper surface of the flange 19, and the upper portion at the other end is fixed by another screw. The column 3f is a rod that fixes between adjacent electrodes, and has a screw hole at one end and a screw that is screwed into the screw hole at the other end. The lower end of the column 3f is screwed to the upper surface of the flange 19, and the upper part, which is the other end, is fixed with another screw.

  Further, the number of drift tube electrodes is not limited to four as long as a uniform electric field can be created in the drift tube 3, and is appropriately changed depending on the length of the drift tube 3.

It has been found that the distance L1 between the bore 6b through which the RH ⁺ beam drilled at the apex of the cone 6a passes and the orifice drilled in the disk 20 improves the attenuation of the proton transfer reaction product. It was. The results are shown in FIG. When the distance was 10 mm, the attenuation of the proton transfer reactant could be remarkably improved.

  FIG. 3 is a diagram for explaining the extruded electrode. FIG. 3A is a plan view of the extruded electrode 9. FIG. 3B is a cross-sectional view taken along the A′-A ′ position in FIG. 3A. FIG. 3C is a rear view of the extruded electrode 9.

  The extrusion electrode 9 is a circular electrode in which a water vapor introduction tube 9a having a water vapor introduction port 2a for introducing water vapor is attached to the upper surface. The holes 9b and 9c are connected and fixed to the flange 19 by the columns 3e and 3f made of an insulating material with other electrodes. There is a recessed portion 9e that is recessed on the back surface, and is fitted to the next first spacer 11. Further, a connector for applying V1 is inserted into the wiring connection hole 9d and energized.

In addition, it is desirable to provide a plurality of water vapor introduction pipes 9a on a cylindrical object. This is because the introduced water vapor does not have a high concentration locally and exists uniformly in the ion generation space 22, and H ₃ O ⁺ can be generated more efficiently by discharge.

  FIG. 4 is a diagram illustrating the extraction electrode. FIG. 4A is a plan view of the extraction electrode 10. 4B is a cross-sectional view taken along the A'-A 'position in FIG. 4A. FIG. 4C is a rear view of the extraction electrode 10.

  The extraction electrode 10 is a circular electrode having a perforation 10a in the center, which is composed of a convex portion 10b protruding in the direction of the extrusion electrode 9 and a concave portion 10f having a recessed back surface. The holes 10c and 10d are connected and fixed to the flange 19 by the pillars 3e and 3f made of an insulating material with other electrodes. The recessed portion 10f having a recessed back surface is fitted with the next second spacer 11d. Further, a connector for applying V1 is inserted into the wiring connection hole 10e and energized.

Providing the convex portion 10b ensures that a certain volume of the ion generation space 22 is ensured, and occurs reliably on the back surface of the extrusion electrode 9 and discharge (shown by a dotted line in FIG. 2), and H ₃ O ⁺ is removed from water vapor. Produced in high concentration. Furthermore, by providing the convex part 10b, the length L2 of the perforation 10a can be secured longer, and the backflow of the sample gas can be further reduced.

The diameter D1 of the perforations 10a was tested at 5 mm, 2 mm, and 1 mm. From the results shown in FIG. 6, the generation efficiency of H ₃ O ⁺ is remarkably improved. 1 mm was the best (results are shown in FIGS. 19 and 20).

  In addition, the recess 10f on the back surface prevents the connection electrode 12 from being discharged, and has an effect of reliably preventing the backflow of the sample gas by increasing the volume of the backflow prevention space 23.

  FIG. 5 is a diagram illustrating the first spacer. FIG. 5A is a plan view of the first spacer 11. FIG. 5B is a cross-sectional view taken along the A'-A 'position in FIG. 5A. The back surface is the same as the plane. The first spacer 11 and the second spacer 11d have the same shape.

  The first spacer 11 has a ring shape with a hole 10a in the center. A groove 11b and a groove 11c are provided on the flat surface and the back surface, respectively, and an O-ring is fitted to seal the upper and lower electrodes.

  FIG. 6 is a diagram illustrating connection electrodes. FIG. 6A is a plan view of the connection electrode 12. 6B is a cross-sectional view taken along the A'-A 'position in FIG. 6A. FIG. 6C is a rear view of the connection electrode 12.

  The connection electrode 12 is an electrode in which a perforation 12a is formed in the center of a recess having a recess 12g that is recessed in the direction of the extraction electrode 10 and a notch 12e that is recessed in the back and in the shape of a mortar. The holes 12b and 12c are connected and fixed to the other electrodes and the columns 3e and 3f made of an insulating material. The recessed portion 12 f that is recessed on the back is fitted with the next sampler 13. Further, a connector for applying V1 is inserted into the wiring connection hole 12d and energized.

  In addition, by providing the mortar-shaped cut portion 12e on the back surface, there is an advantage that the distance through which ions pass through the perforations 12a is shortened, and the loss of ions in the perforations 12a is reduced.

  FIG. 7 is a diagram illustrating the sampler. FIG. 7A is a plan view of the sampler 13. FIG. 7B is a cross-sectional view taken along the A'-A 'position in FIG. 7A. The back surface is the same as the plane.

  The sampler 13 has a hole 13a at the center of a ring-shaped main body, two sample introduction tubes 13d having a sample introduction port 3a on the side surface, and a sample introduction tube 13f, and a sample gas is contained in the sample introduction tubes 13d and 13f. Is provided with a pipe line 13e and a pipe line 13g. Further, a groove 13b and a groove 13c are provided on the flat surface and the back surface, respectively, and O-rings are fitted and sealed to the upper and lower electrodes.

Here, two sample introduction tubes 13d and 13f are provided, but it is desirable to provide a plurality of sample introduction tubes 13d at equal intervals on the side surface. This is because the sample gas can be uniformly introduced into the drift tube 3 and the sample gas can efficiently undergo proton transfer reaction with H ₃ O ⁺ at a high frequency.

  FIG. 8 is a diagram for explaining the drift tube electrode. FIG. 8A is a plan view of the drift tube electrode 14. FIG. 8B is a cross-sectional view at the position A′-A ′ in FIG. 8A. The back surface is the same as the plane. The drift tube electrodes 14, 14e, 14f, and 14g have the same shape. Therefore, description will be made with reference to the drift tube electrode 14.

  The drift tube electrode 14 is a circular electrode having a perforation 14a in the center and a thin ring portion 14h that is recessed in the direction of the sampler 13 and the back surface. The holes 14b and 14c are connected and fixed to the other electrodes and the columns 3e and 3f made of an insulating material. At the bonding portion 14i, the upper and lower insulating materials are contacted. Further, a connector for applying V1 is inserted into the wiring connection hole 14d and energized. The ring portion 14h is preferably as thin as possible in order to make the electric field in the drift tube 3 uniform. In the present invention, it is 1.5 mm.

  FIG. 9 is a diagram illustrating the insulating ring. FIG. 9A is a plan view of the insulating ring 15. FIG. 9B is a cross-sectional view at the position A′-A ′ in FIG. 9A. The back surface is the same as the plane. The insulating rings 15, 15d, 15e have the same shape. Therefore, description will be made with reference to the insulating ring 15.

  The insulating ring 15 has a ring shape with a hole 15a in the center. A groove 15b and a groove 15c are provided on the plane and the back, respectively, and an O-ring 21 is fitted and hermetically fixed to the upper and lower electrodes.

  FIG. 10 is a diagram illustrating an insulator with a tube. FIG. 10A is a plan view of the insulator 16 with a tube. FIG. 10B is a cross-sectional view taken along the A'-A 'position in FIG. 10A. The back surface is the same as the plane.

  The insulator 16 with a tube has a hole 16a in the center of the ring-shaped body, and an exhaust pipe 16d connected to the first pump 3c that adjusts the pressure of the proton transfer reaction space 24 on the side surface and exhausts unnecessary neutral molecules. And a gauge mounting tube 16e for connecting a pressure gauge 3d for monitoring the pressure in the proton transfer reaction space 24 is attached. Further, a groove 16b and a groove 16c are provided on the flat surface and the back surface, respectively, and the O-ring is fitted and the drift tube electrode 14g and the next inlet lens 17 are hermetically fixed.

  FIG. 11 is a diagram illustrating the inlet lens. FIG. 11A is a plan view of the inlet lens 17. FIG. 11B is a cross-sectional view taken along position A′-A ′ in FIG. 11A. FIG. 11C is a rear view of the inlet lens 17.

  The inlet lens 17 is a circular electrode in which a perforation 17a is formed at the center of a concave portion 17d and a concave portion 17e whose interiors are flat and back. An O-ring is fitted in the groove 17c on the back surface and bonded to the next spacer 18 with a conduit. Further, a connector for applying V2 is inserted into the hole 17b and energized.

  FIG. 12 is a diagram for explaining a spacer with a conduit. FIG. 12A is a partially transparent plan view of the spacer 18 with a conduit. FIG. 12B is a cross-sectional view taken along the A′-A ′ position in FIG. 12A. FIG. 12C is a rear view of the conduit spacer 18.

  The spacer 18 with a conduit is a circular insulator having a convex portion 18d whose center projects upward, and a conduit 18b through which nitrogen gas is inserted is opened from the side surface of the convex portion 18d and connected to the groove 18c on the back surface. To do. The conduit 18b penetrates radially from the central perforation 18a to the side surface of the convex portion 18d. Thereby, nitrogen gas of uniform pressure can be injected into the perforations 18a. The injected nitrogen gas functions as an air curtain and blocks the passage of water molecules.

  FIG. 13 is a diagram illustrating a flange. FIG. 13A is a plan view of the flange 19. FIG. 13B is a cross-sectional view at the position A′-A ′ in FIG. 13A. FIG. 13C is a rear view of the flange 19.

  The flange 19 includes a circular plate 19n, a gas inlet pipe 19b, and a connecting pipe 19h. The plate 19n has a recess 19l into which a spacer 18 with a conduit is fitted in a plane, a groove 19g into which an O-ring is fitted, a support 3e for fixing each electrode, a fixing hole 19e for fixing the support 3f, and a wiring for applying a voltage V3. There is a screw hole 19d to be attached. Further, the concave portion 19l has a concave portion 19f into which the disk 20 in which the orifice is drilled is fitted.

In addition, there is a mortar-shaped inclined portion 19k on the back surface. Due to the inclined portion 19k, neutral molecules can be efficiently exhausted by the second pump 4a and the third pump 4b. In the center, a hole 19a through which RH ⁺ passes is formed. Further, a lateral hole 19c through which nitrogen gas is passed is provided inside the plate 19n.

  The gas inlet pipe 19b is a pipe connected to a supply source such as nitrogen gas injected into the perforations 18a of the conduit spacer 18. The connection pipe 19h is a ring provided with a groove 19j into which the O-ring 21a is fitted. The connection pipe 19h is connected to the upper part of the transport chamber 4 and is fixed by a fastener such as a clamp.

  FIG. 14 is a partially enlarged view of FIG. FIG. 14A is a partially enlarged view of FIG. 13B ′. FIG. 14B is a partially enlarged view of FIG. 13C ′.

  The concave portion 19f into which the circular disc 20 wider than the perforations 19a is fitted has a flat shape, and the depth L3 of the concave portion is 0.1 mm or less. Inside, there is a vertical hole 19m which is connected to the horizontal hole 19c and is a passage for nitrogen gas connected to the groove 18c of the spacer 18 with conduit.

  FIG. 15 is a diagram illustrating a disk set in the concave portion of the flange. FIG. 15A is a plan view. FIG. 15B is a cross-sectional view taken along position A′-A ′ in FIG. 15A. The back surface is the same as the plane.

  The disk 20 is made of a conductor such as stainless steel that fits into the recess 19f on the plane of the flange 19. In the center of the disk 20, an orifice 20a having a diameter of about 0.4 mm is formed.

FIG. 16 is a longitudinal sectional view of the beam forming and transporting member. FIG. 17 is a cross-sectional view of the beam forming and transporting portion. Beam shaping transport member 6 comprises a cone 6a, a ring 6c, a cylinder 6d, and the ring 6e, becomes a disk 6f, the trajectory correction portion 6o and ion lens 6z ', dotted arrow RH ⁺ a shown in FIG. 17 Passing position and direction.

The cone 6a is an ion guide having a hollow inside with a distal end narrowing toward the transport chamber 4 and a perforation 6b through which an RH ⁺ beam passes at the apex. It was found that the diameter D2 of the perforation 6b and the inner angle ∠A of the apex of the cone 6a are related to the loss amount of RH ⁺ generated in the drift tube 3. The confirmation test is shown in FIGS. An ion guide such as hexapole may be used instead of the cone 6a.

The ring 6 c is a cylindrical insulator that adjusts the distance between the hole 6 b and the orifice 20 a of the disk 20. The cone 6a and the cylinder 6d are connected. Moreover, since the cone 6a is made of a conductor (SUS), a voltage can be applied. When the voltage is V4 (−60 V), the residual rate of RH ⁺ is increased. Therefore, since the voltage V4 may be applied to the cone 6a, an insulator material is used for the ring 6c.

The cylinder 6d has an ion lens 6z 'through which RH ⁺ passes, and is made of a conductor by dividing the transport chamber 4 and the ion acceleration chamber 5a. The ion lens 6z ′ is composed of three first ion lenses 6x, second ion lenses 6y, and third ion lenses 6z having the same shape, and the first ion lens 6x and the second ion lens 6y are fixed by a fastener 6w. Has been.

  The third ion lens 6z is fixed to the attachment plate 6h with a fastener 6s', and is connected to the attachment plate 6h and the first and second lenses close to the transport chamber 4 via support posts 6q and 6r and the fastener 6w.

  The disk 6 f is a member that is sandwiched between the transport chamber 4 and the ion acceleration chamber 5 a and partitions the transport space 26 and the ion acceleration space 27. A ring 6e is sandwiched between the cylinder 6d and the disk 6f. In order to make it possible to apply a voltage to the cylinder 6d, the ring 6e is made of an insulating material. A groove 6g and a groove 6p are provided on the flat surface and the back surface of the disk 6f, respectively, and the flat surface side is hermetically connected to the transport chamber 4 and the flat surface side to the ion acceleration chamber 5a by an O-ring.

  It is fixed to the disk 6f via the ion lens 6z 'mounting plate 6h, the column 6i, and the column 6j as described above, and is arranged at a predetermined position on the cylinder 6d.

  The ring 6c, the fastener 6c ′, the fastener 6w, the ring 6e, the support 6q, the support 6r, etc. are acetal resins having characteristics similar to metal and rich in flexibility in addition to the above-described Semitron (registered trademark). DuPont / Dellin (registered trademark) may be used.

  The trajectory correcting unit 6o fixes two pairs of parallel electrodes 6k and 6l to the fixing plate 6u with a fastener 6s, is fixed to the mounting plate 6h via a support 6n ', and is positioned at the lower end of the ion lens 6z'. . There is a plate 6m having a perforation 6t at its tip. A member generally used as a conductor may be used.

  FIG. 18 is a diagram for explaining the pressure in the organic compound measuring apparatus according to the present invention. The differential exhaust system according to the present invention is a three-stage exhaust system including a transport space 26 in the transport chamber 4, an ion acceleration space 27 in the ion acceleration chamber 5a, and a flight detection space 28 in the flight chamber 5c.

It is assumed that the flow rate of H ₂ O is about 0.02 l / min, the pressure of the ion generation space 22 is about 5.2 Torr, the pressure of the backflow prevention space 23 is 5.1 Torr, and the flow rate of the sample gas is about 0.18 l / min. At this time, the pressure of the proton transfer reaction space 24 of the drift tube 3 is adjusted to 5.0 Torr by the first pump 3c.

The degree of vacuum in the transport space 26 of the first-stage transport chamber 4 is evacuated by the second pump 4a and the third pump 4b at a flow rate of 10 ⁻⁴ Torr and 320 l / sec.

The degree of vacuum in the ion acceleration space 27 of the ion acceleration chamber 5a is exhausted by the fourth pump 5j at a flow rate of 10 ⁻⁵ to 10 ⁻⁶ Torr and 750 l / sec.

The degree of vacuum in the flight detection space 28 of the flight chamber 5c is 10 ⁻⁶ to 10 ⁻⁷ Torr, and is exhausted by the fifth pump 5k at a flow rate of 250 l / sec. Exhaust by pumps that are driven separately, and the degree of vacuum (Torr) is raised stepwise.

FIG. 19 is a diagram showing a test result when the amount of H ₃ O ⁺ produced due to the difference in the diameter of the extraction electrode perforation is compared. 19A shows a diameter D1 of the perforation 10a of 5 mm, FIG. 19B shows a discharge electrode having a diameter D1 of the perforation 10a of 2 mm, and FIG. 19B discharges water vapor (5.2 Torr) using an extraction electrode having a diameter D1 of 1 mm. It is the result of the mass spectrum which counted the signal of the reagent ion obtained by the MCP detector 5i when pure air was introduced as sample gas (10 kHz, integrated value for 60 seconds). In both cases, the horizontal axis represents the mass number (m / z), and the vertical axis represents the number of signals received by the MCP detector 5i.

  The ridge A of the cone 6a was 50 °, and the voltage conditions were the same as those described with reference to FIGS.

FIG. 19A, FIG. 19B, in either FIG. _19C, and H 3 ^{O +} (mass number ^{_{19), H 3 O + ·}} H 2 O ( mass number 37) that water molecules are added to the H 3 ^{O +} is confirmed strong . Furthermore, signals of NO ⁺ (mass number 30) and O ₂ ⁺ (mass number 32) that are considered to be derived from the backflow of pure air can also be confirmed.

NO ⁺ and O ₂ ⁺ are known to react with an organic compound to generate ions different from the proton transfer reaction, and are considered to be desirably less than 1% with respect to reagent ions. In particular, it can be seen that the condition is sufficiently satisfied when the diameter D1 of the perforation 10a = 1 mm.

From this, the formation of NO ⁺ and O ₂ ⁺ , which are the most undesired when the diameter D1 = 1 mm of the perforations 10a, is suppressed to a low level. Note that even if D1 = 2 and 5, in FIG. From the results shown in FIG. 6, the generation efficiency of H ₃ O ⁺ is remarkably improved.

  This is because there is an annular convex portion 10b having a diameter of 20 mm on the plane side of the extraction electrode 10 constituting the ion source 2, a concave portion 10f on the back side, and the length L2 of the perforation 10a is about 12 mm. Along with this, the sample gas is not mixed. Therefore, it can be said that the holo cathode 35a of Non-Patent Document 2 and the extraction electrode 10 of the present invention are completely different in structure and configuration.

  In addition, in the holocathode discharge type proton transfer reaction time-of-flight mass spectrometer 34 described in Non-Patent Document 2, since the exhaust is performed from the source drift tube 36 as described above, reaction generation due to a discharge other than the intended purpose is generated. Many things will be seen.

FIG. 20 is a diagram showing the results when the amount of H ₃ O ⁺ produced is measured when the diameter of the perforation of the extraction electrode is 1 mm. Under the conditions of FIG. 19C, the influence of interference of ions other than the reagent ions generated by the discharge was confirmed. The horizontal axis is the mass number (m / z), and the vertical axis is the signal intensity.

Since H ₃ O ⁺ (mass number 19) peak count is about 65000, NO ⁺ is about 370 and O ₂ ⁺ is also about 370, both of which are relative to the amount of H ₃ O ⁺ produced. It can be seen that the production ratio is about 0.5%. ^Further, NO _+, an ion by untargeted discharge other than _O ^{2 +} is generated, any ^NO _+, was produced a ratio of _O ^{2 +} or less. Therefore, it can be said that the production concentration of H ₃ O ⁺ by the ion source 2 of the present invention can actually measure a trace component in the atmosphere with sufficient accuracy.

FIG. 21 is a diagram showing a result of comparing the distance L1 between the disk set on the flange and the apex of the cone, and the diameter D2 of the perforation drilled in the cone and the amount of H ₃ O ⁺ generated. FIG. 21A shows the detection result when the diameter D2 of the perforation 6b is 2 mm, and FIG. 21B is the detection result when the diameter D2 of the perforation 6b is 3 mm. The horizontal axis represents the length (mm) of L1, and the vertical axis represents the number of signals received by the MCP detector 5i.

Incidentally, Symbols ○ is _H 3 ^{O +} (mass number 19) in the figure, the symbol □ represents a detection result of the ^{_{H 3 O + · H 2 O}} ( mass number 37). In addition, ∠A = 50 ° was used, and other conditions were the same as those in FIG. 19C.

  In both FIGS. 21A and 21B, the maximum detection amount was obtained when L = 1 mm. Further, the diameter D2 of the perforations 6b was not significantly different between 2 mm and 3 mm. However, at 1 mm or less and 5 mm or more, when the test was performed under the same conditions as this time, the detected value was extremely lowered. It is considered that the diameter D2 of the perforations 6b affects the pressure in the transport space 26 and the ion acceleration space 27.

FIG. 22 is a diagram showing a result of comparing the remaining amount of H ₃ O ⁺ due to the difference in the angle ∠A of the apex of the cone. 22A shows the detection result when ∠A is 100 °, and FIG. 22B shows the detection result when ∠A is 135 °. The horizontal axis represents the length (mm) of L1, and the vertical axis represents the number of signals received by the MCP detector 5i.

Symbols ○ is _H 3 ^{O +} (mass number 19) in the figure, the symbol □ represents a detection result of the ^{_{H 3 O + · H 2 O}} ( mass number 37). Further, D2 = 2 mm, and other conditions were the same as in FIG. 19C.

In both FIG. 22A and FIG. 22B, the detection sensitivity as a whole is lower than that in FIG. This is because ∠A has an obtuse angle compared to FIG. 21, and the electric field obtained by applying the voltage V4 is affected by the shape of the cone 6a, so that H ₃ O ⁺ generated in the ion generation space 22 is a proton. It is considered that the frequency with which the product obtained in the movement reaction space 24 is incident on the perforations 6b is lowered. Although overall ion loss can be confirmed, as in FIG. 20, when L1 = 10 mm, the loss rate of H ₃ O ⁺ was the lowest and a good result was obtained.

  Therefore, according to the present invention, since it is small and does not use a radiation source, it is possible to measure organic compounds brought into the observation site, particularly trace volatile organic compounds in the atmosphere, at high sensitivity and in real time at the same time. Became.

It is a cross-sectional schematic diagram of the measuring apparatus of the organic compound which is this invention. It is a cross-sectional schematic diagram of an ion source, a drift tube, and a transport chamber. It is a figure explaining an extrusion electrode. It is a figure explaining an extraction electrode. It is a figure explaining a 1st spacer. It is a figure explaining a connection electrode. It is a figure explaining a sampler. It is a figure explaining a drift tube electrode. It is a figure explaining an insulating ring. It is a figure explaining an insulator with a tube. It is a figure explaining an inlet lens. It is a figure explaining the spacer with a conduit | pipe. It is a figure explaining a flange. FIG. 14 is a partially enlarged view of FIG. 13. It is a figure explaining the disk set to the recessed part of a flange. It is a perspective view of a beam shaping transport member. It is sectional drawing of a beam forming transport member. It is a figure explaining the pressure in the measuring apparatus of the organic compound which is this invention. Is a diagram showing test results when comparing the amount of H ₃ O ⁺ due to the difference in diameter of the perforations of the extraction electrode. Shows the results measured for H ₃ O ⁺ the amount of time that the diameter of the perforations of the extraction electrode and 1 mm. Is a diagram showing a result of comparing the diameter D2 and H ₃ O ⁺ yield of perforations bored in the distance L1 and the cone with the vertex of the disk and cone are set to the flange. It is a diagram showing the results of a comparison of the H ₃ O ⁺ of the remaining amount due to the difference in angle ∠A vertex of the cone. It is a schematic diagram of the proton movement reaction time-of-flight mass spectrometer (FIG. 1 of nonpatent literature 1) which consists of an ion source using radiation. It is a schematic diagram of the proton movement reaction time-of-flight mass spectrometer (FIG. 1 of a nonpatent literature 2) which consists of an ion source using electric discharge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic compound measuring device 2 Ion source 2a Water vapor inlet 3 Drift tube 3a Sample inlet 3b Nitrogen inlet 3c First pump 3d Pressure gauge 3e Strut 3f Strut 4 Transport chamber 4a Second pump 4b Third pump 5 Flight time type Mass spectrometer 5a Ion acceleration chamber 5b Orbit adjustment unit 5c Flight chamber 5d Ion detection unit 5e Orbit correction unit 5f Pulser box 5g Pulse extraction electrode 5h Ion lens 5i MCP detector 5j 4th pump 5k 5th pump 6 Beam shaping transport member 6a Cone 6b Drilling 6c Ring 6c 'Retaining tool 6d Tube 6e Ring 6f Disk 6g Groove 6h Mounting plate 6i Strut 6j Strut 6k Parallel electrode 6l Parallel electrode 6m Plate 6n Strut 6n' Strut 6o Track correcting part 6p Groove 6p Groove 6p Ingredient 6 'Fastening tool 6t Perforation 6u Fixed plate 6w Fastening tool 6x First ion lens 6y Second ion lens 6z Third ion lens 6z' Ion lens 7 Time converter 8 Calculator 8a First pulse generator 8b Second pulse generator 9 Extrusion Electrode 9a Water vapor introduction tube 9b Hole 9c Hole 9d Wiring connection hole 9e Recess 10 Extraction electrode 10a Drill 10b Protrusion 10c Hole 10d Hole 10e Wiring connection hole 10f Recess 11 First spacer 11a Hole 11b Groove 11c Groove 11d Second spacer 12d 12a hole 12b hole 12c hole 12d wiring connection hole 12e notch 12f recess 12g recess 13 sampler 13a hole 13b groove 13c groove 13d sample introduction tube 13e tube 13f sample introduction tube 13g tube 14 drift tube electrode 14a hole 14b hole 14b hole 14b 14 Wiring connection hole 14e Drift tube electrode 14f Drift tube electrode 14g Drift tube electrode 14h Ring part 14i Adhesion part 15 Insulation ring 15a Hole 15b Groove 15c Groove 15d Insulation ring 15e Insulation ring 16 Insulator with tube 16a Hole 16b Groove 16c Groove 16d Exhaust pipe 16d 16e Gauge mounting tube 17 Inlet lens 17a Perforated 17b Hole 17c Groove 17d Recessed portion 17e Recessed portion 18 Spacer with conduit 18a Perforated 18b Conduit 18c Groove 18d Convex portion 19 Flange 19a Perforated 19b Gas inlet tube 19c Side hole 19d Recessed hole 19e Recessed hole 19e Groove 19h Connecting pipe 19j Groove 19k Inclined portion 19l Recessed portion 19m Vertical hole 19n Plate 20 Disc 20a Orifice 21 O-ring 21a O-ring 22 Ion generation 23 Propagation reaction space 26 Transport space 27 Ion acceleration space 28 Flight detection space 29 Proton transfer reaction time-of-flight mass spectrometer 30 Radiation source 30a Water vapor inlet 31 Drift tube 31a Electrode 31b Spacer 31c Sample inlet 32 Transport Chamber 32a Ion Lens 33 Time-of-Flight Mass Spectrometer 33a Ion Acceleration Chamber 33b Flight Chamber 33c Reflectron 33d MCP Detector 33e Time Converter 33f Pulse Extraction Electrode 33g Orbit Correction Unit 34 HoroCathode Discharge Proton Transfer Reaction Time-of-Flight Mass Spectrometry Total 35 Ion source 35a Holo cathode 35b Water vapor inlet 36 Source drift tube 36a Sample inlet 37 Drift tube 37a Electrode 38 Transport chamber 38a Ion lens 3 8b First pump 39 Time-of-flight mass spectrometer 39a Ion acceleration chamber 39b Flight chamber 39c Reflectron 39d MCP detector 39e Pulsar box 39f Pulse extraction electrode 39g Orbit correction part 39h Second pump

Claims (10)

In a proton transfer reaction time-of-flight mass spectrometer comprising a discharge ion source, a drift tube, a transport chamber, a beam shaping transport member, and a time-of-flight mass spectrometer,
The ion source is an extruded electrode having a water vapor inlet, a first spacer that is an insulator disposed next to the extruded electrode, and a protrusion that is disposed next to the first spacer and protrudes toward the extruded electrode. An extraction electrode having a perforation in the center of the electrode, a second spacer, which is an insulator disposed next to the extraction electrode, and a mortar-shaped notch on the back surface disposed next to the second spacer. It consists of a connecting electrode with a perforation in the center,
An organic compound characterized in that discharge is caused at the convex portions of the extrusion electrode and the extraction electrode in the ion generation space formed by the extrusion electrode, the first spacer, and the extraction electrode, and water vapor is changed to H ₃ O ⁺ . measuring device.   An apparatus for measuring an organic compound, which is a proton transfer reaction time-of-flight mass spectrometer using the ion source according to claim 1.   3. The organic compound measuring apparatus according to claim 1, wherein the perforations formed in the extraction electrode have a diameter of 0.5 mm to 2 mm. A perforation through which ions pass is drilled in the center, and a spacer with a conduit having a plurality of conduits and vertical holes inside partitions the proton transfer reaction space in the drift tube and the ion transport space in the transport chamber, and at the center of the perforation. The organic compound measuring device according to any one of claims 1 to 3, wherein a gas is jetted inward to prevent a neutral gas in the drift tube from passing therethrough. A beam shaping transport member disposed in the transport chamber allows ions that have passed through the transport chamber to pass through perforations drilled at the apex of a cone whose inner angle is 90 ° or less, and is a time-of-flight mass spectrometer The organic compound measuring apparatus according to claim 1, wherein the organic compound measuring apparatus is transported to a pulse extraction electrode . 6. The organic compound measuring apparatus according to claim 5, wherein a diameter of a perforation formed at the apex of the cone is 2 to 3 mm. Measurements of the organic compound according to claim 5 or claim 6, the distance to the orifice of the disk that is set in the recess of the flange, characterized in that it is 15mm or less from 5mm constituting the drift tube from the apex of the cone apparatus. 8. The organic compound measuring apparatus according to claim 5, wherein a voltage is applied to the cone. An ion source that discharges the injected water vapor to generate H ₃ O ^+, and is connected to the ion source, reacts the H ₃ O ⁺ and the sample gas, and reacts with R to RH ⁺ , which are volatile organic compounds to be measured. A drift tube, a transport chamber connected to the drift tube, a time-of-flight mass spectrometer connected to the transport chamber, and an ion acceleration chamber of the transport chamber and the time-of-flight mass spectrometer A method for measuring an organic compound comprising a beam-shaping transport member and not exhausted by the ion source. 10. The method for measuring an organic compound according to claim 9, wherein a voltage is applied to the extrusion tube, the extraction electrode and the connection electrode of the ion source, and the drift tube electrode constituting the drift tube with the same power source.

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