WO2008153199A1

WO2008153199A1 - Ionization analysis method and device

Info

Publication number: WO2008153199A1
Application number: PCT/JP2008/061169
Authority: WO
Inventors: Kenzo Hiraoka
Original assignee: University Of Yamanashi
Priority date: 2007-06-15
Filing date: 2008-06-12
Publication date: 2008-12-18

Abstract

It is possible to easily perform analysis with a high sensitivity. An ion sample tube (11) and a discharge gas supply tube (12) constitute a double tube unit (10) to serve as one electrode. The other electrode is a flat electrode (21), on which a dielectric plate (9) is arranged. A sample (S) is placed on the dielectric plate (9). When AC voltage is applied between the two electrodes (10, 21), barrier discharge occurs and ionizes molecules of the sample (S). The ions are introduced through the sample tube (11) to an analysis device (60).

Description

Ionization analysis method

Technical field

The present invention relates to a method and apparatus for ionization analysis under atmospheric pressure of a sample.

To do.

Background art

An ionization analysis method and apparatus for direct analysis in real time (DART) under atmospheric pressure has already been proposed. Robert B. Cody, James A. Laramee, and H. Dupont Durst "Versatile New Ion Source for the Analysis of Materials in Open Air under Ambient Conditions" Analytical Chemistry, Vol. 77, No. 8, April 15, 2005 2297. '

In this method, heated rare gas such as helium gas is excited by DC corona discharge, and the generated ions and excited species are ejected from a nozzle and sprayed onto the sample. As a result, the molecular ions derived from the sample ionized are blown away by the sprayed gas. Only a part of the blown ions are introduced into the mass spectrometer through the orifice. Therefore, it comes at the expense of great detection sensitivity. In addition, a large amount of helium gas is consumed, so it is not economical.

Disclosure of the invention

The present invention provides an ionization analysis method and apparatus capable of analyzing even a very small amount of sample with high sensitivity. The ionization method according to the present invention applies an alternating voltage between at least two electrodes to generate a barrier discharge in a space including the surface of the dielectric disposed across the discharge current path, and the generated variability. This includes supplying the target sample to the position exposed to the discharge.

In the ionization analysis method according to the present invention, an AC voltage is applied between at least two electrodes, and a barrier discharge is generated in the space including the surface of the dielectric disposed across the discharge current path. This includes supplying the sample to be analyzed to a position where it is exposed to the barrier discharge, and guiding ions of the sample generated by exposure to the barrier discharge to the analyzer.

The ionization apparatus according to the present invention comprises a dielectric and at least two electrodes to which an AC voltage is applied between them, and the surface of the dielectric faces in or near the space where the sample to be analyzed is supplied. The dielectric is disposed across the discharge current path of the barrier discharge so that a barrier discharge is generated in a space including the surface of the dielectric by applying an AC voltage between the electrodes. Is. In addition, an ion introduction path is provided that guides the sample ions generated when the sample to be analyzed is exposed to a barrier discharge to the analyzer. Furthermore, an ionization analyzer can be realized by providing a mass analyzer that can guide ions.

By supplying rare gas such as helium gas and other discharge gas, the barrier discharge becomes larger and more stable.

If the sample is solid or liquid, the sample may be placed on, or pasted on, or near the surface of the dielectric. If the sample is a gas, it can be supplied through the sample supply tube.

According to the present invention, only the portion of the sample exposed to the barrier discharge becomes a high-energy state and is desorbed and ionized without undergoing thermal decomposition. The ion production mechanism by the Parry discharge is not necessarily analyzed clearly, but ions are generated directly in the discharge plasma or by metastable excited species (such as He *) generated by rare gas discharge such as helium. It is thought to be ionized.

The barrier discharge is characterized by a low plasma gas temperature (estimated to be around 100 ° C), and the holding member such as the sample or the substrate holding the sample is not heated. The substrate does not thermally decompose to generate impurity ions.

Since the barrier discharge is an AC discharge, it generates not only positive ions but also negative ions that are difficult to observe normally. This is because a large amount of electrons are generated by the barrier discharge. In barrier discharge, a large amount of electrons are generated by plasma, so if an appropriate mass spectrometer is used, a compound with a high electron affinity (ie, a positive electron affinity) can be easily converted into a negative ion. Can be detected.

Sample molecules are ionized as described above by barrier discharge plasma. The barrier discharge occurs on the solid surface (creeping discharge) and the space above it, so the ion generation area is wide. For this reason, although the amount of current is small, the amount of ion generation is large and the detection sensitivity is high. When noble gas helium is used, it is also ionized (penning ionization) by metastable excited species (such as He *) of noble gas atoms generated in the discharge plasma, so it is extremely efficient and highly sensitive. Ionization method.

In this way, almost all or many of the generated ions can be directly aspirated and directed to a mass spectrometer (mass spectrometer) for analysis.

By using one of the two electrodes as an electrode with a sharp tip, ionization and analysis of a small region of the sample becomes possible. Two-dimensional imaging is also possible by scanning the electrode or sample. In this way, according to the present invention, it is possible to ionize and analyze samples very easily at atmospheric pressure. This invention can be applied to all solid, liquid, and gas samples. In other words, it can be applied to all specimens such as banknotes, cloth, soil, dry biological tissue samples, pigments, powders, plastics, wood, and inorganic materials.

There are various embodiments of this invention. For example, the sample tube that guides the sample ion to the analyzer and the gas supply tube that supplies the discharge gas have a double structure, and one end of each of them faces the space where barrier discharge occurs. Arrange them. Alternatively, the sample tube that guides the sample ions to the analyzer and the sample supply tube that supplies the sample gas have a double structure, and they are arranged so that one end of them faces the space where barrier discharge occurs. . In these cases, either the sample tube, the gas supply tube, or the sample supply tube, which is arranged so that one end faces the space where the Parry discharge occurs, is used as the first electrode, and the dielectric It is desirable to place a flat plate-like second electrode on the opposite side of the surface, and apply an AC voltage between these first and second electrodes.

When the above-described double tube structure is used, the apparatus configuration becomes very simple.

In addition, by surrounding the space where the barrier discharge occurs with a cylindrical body, wall, tube, cap, guide, etc., it is possible to sample the generated ions effectively and prevent discharge gas from divergence. Can be planned.

The two electrodes may be arranged so as to sandwich the dielectric, or the two electrodes may be arranged on the opposite side of the surface of the dielectric.

In the latter case, for example, the configuration of the ionizer is embedded in an electrode support made of an insulator provided with an ion introduction path, and the ion support is embedded with the ion introduction path in between. 2 electrodes and placed to cover the above electrodes And a dielectric with a hole leading to the ion introduction path. In this case, it is preferable to further include an encircling tubular body disposed on the dielectric so as to enclose the hole.

The present invention can also be applied to a material chemical processing method and apparatus using barrier discharge.

The chemical treatment method according to the present invention applies an alternating voltage between at least two electrodes to cause a barrier discharge in a space including the surface of the dielectric disposed across the discharge current path. Including supplying a material to be processed to a position exposed to the generated barrier discharge.

A chemical processing apparatus according to the present invention includes a dielectric on which a material to be processed is placed, at least two electrodes arranged with the dielectric interposed therebetween, and a power supply device that supplies an AC voltage to the two electrodes. Is. Brief Description of Drawings

Fig. 1 shows the configuration of the ionizer according to the first embodiment.

Figure 2 shows a variation of the ionizer.

Figure 3 shows a modification of the double pipe section.

Figure 4 shows an example of the detection target applied to the ionizer and its arrangement.

Figure 5 shows examples of other detection objects applied to the ionizer and their arrangement.

Figure 6 shows another variation of the ionizer.

Section 7 shows another variation of the ionizer.

Figure 8 shows another variation of the ionizer.

Figure 9 shows a modification of the tip of the double pipe.

Fig. 10 shows that the ionizer is a chemical treatment device (including a surface processing device). Shows how to apply.

Fig. 11 shows the configuration of the ionizer according to the second embodiment. .

Figure 12 shows how a gas sample is collected.

Figure 13 shows how a gas sample is collected.

Figure 14 shows how a gas sample is collected.

FIG. 15 is a plan view showing the configuration of the ionization apparatus according to the third embodiment. FIG. 16 is an assembled perspective view of the ionization apparatus shown in FIG.

FIGS. 17 to 19 show data demonstrating that various substances can be detected using the ionization analyzer according to the above-mentioned embodiment. FIG. 17 uses the apparatus shown in FIG. Fig. 18 shows the analysis result of hexane vapor using the apparatus shown in Fig. 11, and Fig. 19 shows the apparatus shown in Fig. 4. It is a graph which shows the analysis result of the ethyl acetate solution of metafidophos used. BEST MODE FOR CARRYING OUT THE INVENTION

Example 1

FIG. 1 shows an ionization apparatus (or ionization analysis apparatus) according to a first embodiment of the present invention.

The ion introduction part of mass spectrometer 60 (any mass spectrometer of the type that introduces ION such as time-of-flight mass spectrometer, ion trap mass spectrometer, quadrupole mass spectrometer, etc.) can be used in a conical shape. This skimmer (or sampling 'orifice) 61 is provided, and a thin sample tube connection 61A extends outward from the center of the skimmer 61 that protrudes outward. A sample tube (ion's sampling tube, ion introduction tube) (capillary) 11 is connected to the connection 61 A by a joint (force puller) 62 made of an insulator such as ceramic. . In this example, the sample tube 11 Extends straight from the skimmer 61 of the mass spectrometer 60 through the connection 61A and the fitting 62, but at least one of the connection 61A, the fitting 62 and the sample tube 11 has a flexible structure or can be expanded and contracted. As a simple structure, the tip of the sample tube 11 can be placed at an arbitrary position at an arbitrary angle. This also applies to the modified examples and other examples described later.

The sample tube 11 is inserted into the outer tube 12 from the tip to the middle. In comparison with the outer tube 12, the sample tube 11 may be called an inner tube. There is a gap (space) between the inner tube 11 and the outer tube 12. In this embodiment, since the discharge gas (or carrier gas) is supplied through the space between the inner tube 11 and the outer tube 12, the outer tube 12 may be called a discharge gas supply tube or a gas supply tube. .

The end of the sample tube 11 on the joint 62 side protrudes outward from the tube wall of the gas supply tube 12. The portion where the sample tube 11 and the gas supply tube 12 are doubled is called a double tube or double tube 10. In this embodiment, the sample tube 11 and the gas supply tube 12 are both made of metal, and at least one of them serves as an electrode for barrier discharge as described later. In addition, the tip of the sample tube 11 protrudes slightly outward (for example, several millimeters) from the gas supply tube 12. Depending on the implementation, the tip end of the sample tube 11 and the gas supply tube 12 may be substantially the same position, or the tip of the gas supply tube 12 may protrude beyond the tip of the sample tube 11. May be. More preferably, either one or both of the sample tube 11 and the gas supply tube 12 are configured to be extendable.

A dielectric (insulator) (glass, quartz, alumina, etc.) is provided to generate the barrier discharge. In this embodiment, a dielectric plate 9 (for example, a thickness of about 1 mm) is used. The dielectric plate 9 is also used as a table on which a sample to be analyzed (for example, cloth, banknote, mud, dried biological tissue sample or other specimen, solid sample, etc.) S is placed, applied or adhered. Sample solution with dielectric plate 9 It can be dropped onto the sample as it is, or it can be dried and used as a sample.

The tip of the double tube 10 is slightly spaced from the surface of the dielectric plate 9 on which the sample S is placed (for example, the tip of the sample tube 11 is separated from the sample S by several dragons or less). Position the double tube 10 and the dielectric plate 9 so that they face each other, and place a flat plate electrode 21 (metal or conductor such as copper) on the other side of the dielectric plate 9 in contact with the dielectric plate 9 Deploy. For example, the plate electrode 21 and the dielectric plate 9 are fixed on a support base, and the sample tube 11 extending from the mass spectrometer 60 is brought together with the gas supply tube 12 to one side of the dielectric plate 9. Preferably, the sample tube 11 is arranged perpendicular to one surface of the dielectric plate 9. The above support (or the plate electrode 21 and the dielectric plate 9) can be moved up and down (in the direction of approaching and moving away from the sample tube 11) or two-dimensionally by using an XY table. It may be movable in the direction (surface direction perpendicular to the sample tube 11). A support column having an arm can be erected on the support base, and the double pipe portion 10 can be supported by the arm.

The output terminal of the power supply device 30 is connected between the gas supply pipe 12 and the plate electrode 21 via a current limiting resistor 31 (for example, about 50 to 100 Ω). An AC voltage (for example, a voltage) is provided between the gas supply pipe (electrode) 12 and the sample pipe 11 (in this embodiment, both pipes 1 1 and 12 are in electrical contact) and the plate electrode 21 by the power supply 30. Hundreds of volts to several kilovolts and a frequency of several kilohertz to several tens of kilohertz). The AC (high frequency) voltage is preferably a rectangular wave, but may be a sine wave or other waveform. The end of the gas supply pipe 12 is connected to the gas output port of a discharge gas supply apparatus (eg, gas cylinder) 40. The gas supply pipe 12 is connected to a discharge gas (rare gas such as helium (He), nitrogen , Oxygen, etc.). The discharge gas is blown from the tip of the gas supply tube 12 to the sample S or the dielectric plate 9. By applying an AC voltage between the gas supply pipe 12 and the sample pipe 11 and the flat plate electrode 21, the tips of the gas supply pipe 12 and the sample pipe 11 function as electrodes. In this embodiment, the tip of the sample tube 1 is more protruding than the gas supply tube 12, so that the tip of the sample tube 11 and the dielectric plate 9 or the tip of the sample tube 11 and the sample S is In the meantime, a barrier discharge occurs. Part or all of sample S is exposed to local plasma by barrier discharge. Only the part of the sample that is exposed to the barrier discharge is in a high-energy state and is desorbed and ionized without thermal decomposition. Ions are considered to be ionized directly in the discharge plasma or by metastable excited species (such as He *) generated by rare gas discharges such as helium. On the other hand, the mass spectrometer 60 is kept in a high vacuum, and the tip of the sample tube 11 is in or near the space where the barrier discharge occurs, so that the local plasma generated by the barrier discharge is in the local plasma. Most of the ions are attracted directly to the mass spectrometer 60 through the sample tube 11 without being diffused into the outside air, and are subjected to mass analysis. This achieves ultra-sensitive ion detection.

A barrier discharge is characterized by a low plasma gas temperature (estimated to be around 100 ° C) while the electron temperature is as high as tens of thousands of degrees. Since the dielectric plate 9 is not heated, these materials do not thermally decompose to generate impurity ions. Since the barrier discharge is an AC discharge, it generates not only positive ions but also negative ions that are usually difficult to observe. This is because a large amount of electrons are generated by the barrier discharge. In barrier discharge, a large amount of electrons are generated by plasma, so if an appropriate mass spectrometer 60 is used, a compound with a high electron affinity (ie, a positive electron affinity) can be easily converted to a negative ion. Can be detected. When helium gas is used as the discharge gas or carrier gas, there is an advantage that the discharge occurs extremely stably. Also, using noble gas As a result, a large amount of long-lived metastable excited state rare gas atoms are generated, and ionization of the sample can be promoted. This process is called Penning ionization.

He * (metastable excited species) + M → He + M + + e (Penning ionization) However, a barrier discharge may be generated at atmospheric pressure without supplying a discharge gas. -In the above example, since the sample tube 11 and the gas supply tube 12 are electrically connected, a barrier discharge is generated between the tip of the sample tube 11 and the sample S or the dielectric plate 9. However, if the sample tube 11 and the gas supply tube 12 are electrically insulated, no barrier discharge will occur at the tip of the sample tube 11. The sample pipe 1 1 and the gas supply pipe 12 may be insulated, and the sample pipe 11 may be connected to the power supply 30 as indicated by the broken line. It is also possible to apply AC voltage only to sample tube 11 without applying AC voltage.

Preferably, a surrounding tube (cylindrical or other shaped tubular body) 16 is arranged outside the double tube portion 10 with a space therebetween to surround the double tube portion 10. The lower end of the enclosure 16 is in contact with the sample S or the surface of the dielectric plate 9 with a very small distance or contact. 'This prevents the discharge gas ejected from the lower end of the gas supply pipe 12 from being mixed with the atmosphere. If the flow rate of the discharge gas to be supplied is high, the enclosure 16 is not necessarily required. The surrounding cylinder 16 can be supported by a support arm provided on the above-mentioned support base or other appropriate support member, and can be fixed to the dielectric plate 9, or by the arm 16a. The gas supply pipe 12 may be fixed at a plurality of locations.

The current limiting resistor 31 is used to prevent an excessive current from flowing accidentally, thereby ensuring safety and preventing the power supply device 30 from being damaged. Current control The limiting resistor 31 is not necessarily provided.

The analysis device 60 (skimmer 61) and the sample tube 1 1 are connected by an insulating joint 62 in order to reduce the adverse effects on the analysis device 60 due to the high-frequency voltage applied to the electrodes 12, 21 and the high-frequency noise generated by the barrier discharge. However, in experiments, there was no negative effect of noise even when the sample tube 11 was connected directly to the analyzer 60 (skimmer SI) without the insulating joint 62 being provided. The insulating joint 62 is not necessarily provided.

Since these current limiting resistors 31 and insulating members (insulating joints 62) may be provided as necessary, the following modifications and other examples will not be shown or described. To do. Also, the illustration and explanation of the discharge gas supply device 40, the surrounding tube 16, and in some cases the power supply device 30 are omitted in the following modifications and other embodiments in order to avoid complexity. Furthermore, in the following modifications and other embodiments, the same components as those shown in FIG.

Any mass spectrometer can be used as the analyzer 60 as long as it is a mass spectrometer equipped with an atmospheric pressure ion source. Ions can be measured simply by bringing a barrier-discharge ion source close to the ion, sampling, and orifices on the atmosphere side of the mass spectrometer. Examples of mass spectrometers that can be used include time-of-flight mass spectrometers (orthogonal), ion trap mass spectrometers, and quadrupole mass spectrometers (also known as mass filters).

In particular, when a quadrupole mass spectrometer is used, there are the following advantages.

Since the barrier discharge is an AC discharge, positive ions and negative ions are generated alternately in the discharge section. In other words, depending on the electrode of the discharge, it is generated in a swarm form of positive ions and negative ions. Since ions become swarms (a gaseous mass), the phenomenon that positive ions and negative ions are lost by their recombination reaction is unlikely to occur. Barrier discharge Ion generation using is an excellent source of ions. Such positive ion swarms and negative ion swarms are continuously supplied to the quadrupole mass spectrometer. Since the quadrupole mass spectrometer has exactly the same mass spectrometry function for positive and negative ions, it is sufficient to reverse the polarity of the ion focusing electrode alternately (positive and negative potentials). A single quadrupole mass spectrometer can measure positive and negative ions.

Figure 2 shows the deformation. As the inner pipe (sample pipe) of the double pipe section 10, an insulating sample pipe 1 1 A is used. Sample tube 1 1 A is a quartz tube, for example, and is connected to connection 61 A of clearance 61 by joint 63. In this way, either the inner tube or the outer tube of the double pipe portion 10 can be formed of an insulator.

FIG. 3 shows still another modified example, and shows only the tip of the double tube 10. Fit an enclosure (cap) 17 made of an insulator (eg glass, ceramic, etc.) to the tip of the outer tube 12 of the double tube 10. If the tip of the surrounding cylinder 17 is brought into contact with the surface of the dielectric plate 9, the distance between the tip of the inner tube 11 and the outer tube 12 and the surface of the dielectric plate 9 is always kept constant (optimum value). be able to. In this example, it is preferable that the size of the sample S is within the enclosure 17.

4 and 5 show examples of detection objects and their arrangements.

In Fig. 4, the detection object S is the paper soaked with the sample, cloth, plastic, banknotes, etc. used for wiping inspection. These objects are the tip of the double tube 10 and the dielectric plate 9 In other words, it can be placed in a space where a barrier discharge occurs. This simplicity is a feature of ionization analyzers using barrier discharge.

In addition, as shown in Fig. 5, secretions from animal skin such as fingers can be detected. In this case, the finger or the like directly discharges the barrier. Just place it in the space. The current flowing by the Parrier discharge is extremely small and is harmless to humans. However, it is preferable to consider increasing the applied voltage gradually and carefully, making it as low as possible, and using the current limiting resistor described above.

FIG. 6 shows a modification in which an AC voltage is not applied to the inner tube and the outer tube of the double tube section 10. These inner tube 11 and outer tube 12 are preferably formed of an insulator. A small electrode 22 is placed (fixed) on the opposite side of the plate electrode 21 across the dielectric plate 9. The double tube portion 10 is located directly above the electrode 22. The shape of the electrode 22 may be circular, square, or other shapes.

When an AC voltage is applied between the two electrodes 21 and 22, a barrier discharge is generated around (near) the small electrode 22. Place an object S such as cloth soaked with the sample so that it is exposed to this barrier discharge. The sample ions generated by the barrier discharge are guided to the analyzer 60 through the inner tube 11. If discharge gas such as helium is supplied through the outer tube 12, the barrier discharge becomes larger and stable. This modification has a simple configuration because no AC voltage is applied to the double tube 10.

In the modified example shown in Fig. 7, discharge gas is supplied from the inner tube 11 B of the double tube section 10 and ions are sucked into the analyzer 60 by the outer tube 12 B. The upper end of the outer pipe (sample pipe) 12 B is formed thin, and is connected to the connection 61 A of the skimmer 61 by a joint 64. Inner pipe (gas supply pipe) 1 1 B is led to the outside from the middle of outer pipe 12 B, connected to a discharge gas supply device (not shown), and discharge gas such as helium gas is supplied. The In this configuration, since the discharge gas is ejected from the tip of the thin inner tube 11 B, the barrier discharge tends to occur near the tip of the inner tube 11 B, that is, within a fairly narrow range (local In particular, it has the feature that it can cause barrier discharge. A voltage is applied between the inner tube 11 B and the dielectric plate 9 so that the tip of the inner tube 11 B protrudes beyond the tip of the outer tube 12 B. However, the tip of the outer tube 12B may be made to protrude from the tip of the inner tube 11B (the outer tube 12B may be formed of an insulator), or as shown in FIG. The tube 17 may be attached to the tip of the outer tube 12B.

As shown in Fig. 8, the tip of the inner tube (sample tube) 11C of the double tube 10 may be cut diagonally to have a sharp tip. Since a barrier discharge occurs at the tip of the inner tube 11C (an AC voltage is applied to the inner tube 11C), ion analysis of a small region of the sample S can be performed. Therefore, by scanning the dielectric plate 9 and the plate electrode 21 on which the sample S is placed in a plane parallel to the plane (plane perpendicular to the inner tube 11C) (XY plane), a spatial resolution of less than mm is obtained. Can perform two-dimensional imaging of samples (for example, molecular imaging of biological tissues with cancer cells). In this case, it is preferable to intermittently scan the sample two-dimensionally and apply an alternating voltage in pulses at each position.

Fig. 9 shows a further modification. The tip of the inner tube 11D is cut shorter than the outer tube 12, and a needle-like electrode 13 extending on the extension of the inner tube 11D is provided at the tip of the inner tube 11D. In addition, a thin insulating capillary (capillary) li d is connected to the inner tube 11D. The tip of the thin tube lid is arranged so as to face the needle electrode 13. Since the needle electrode 13 is used, the range of barrier discharge can be further narrowed. The generated ions are sucked from the tip of the insulating tube lid.

Fig. 10 shows the configuration shown in Fig. 8, in which the material M to be processed is placed on the dielectric plate 9 instead of the sample S to be analyzed, and the surface processing of the material M is performed. .

For example, if a synthetic polymer sheet M is inserted between the inner tube (electrode 11C) and the dielectric plate 9, the surface of the synthetic polymer is etched by plasma. In etching using this barrier discharge, if polymer or paper is burnt, This phenomenon does not occur at all. In other words, the barrier discharge does not increase the temperature enough to melt or scorch the polymer film. When a polymer film or the like is exposed to a barrier discharge, the surface is plasma-treated and can be chemically etched. For example, when a water-repellent polymer film is exposed to a barrier discharge, the hydrophilicity of the exposed part of the plasma improves and only the plasma-treated part gets wet.

In this way, the Parrier discharge can be chemically modified only on its surface without destroying the material. By appropriately adjusting the shape of the electrode (inner tube) facing the dielectric plate 9, the area of the film to be chemically modified can be freely changed. If the tip is pointed as shown, only the local area of the organic molecular material can be selectively chemically modified. For example, if helium is mixed with hydrogen and discharged, the local area can be reduced. Helium / oxygen can be oxidized, and helium / nitrogen can be nitrided. By changing the gas mixed with this potassium, the chemical composition of the material surface can be freely treated. This method is extremely simple and efficient. According to this method, the etching process of polymer materials can be controlled while observing the generated ions with an analyzer.

Barrier discharge can be used for chemical processing without raising the temperature of the material. Therefore, a new functional material can be synthesized on the surface by placing various chemically reactive substances on the material surface and subjecting it to barrier discharge treatment. You can also For example, in the manufacture of fuel cell catalysts, it is possible to synthesize thin film catalysts with new functions by mixing various reactants on the surface to make them thin and then subjecting them to barrier discharge. Techniques such as applying a metal catalyst on the graph item are also possible.

In this way, local chemical modification of materials is possible (such as local etching and chemical modification of organic nanomaterials. Surface etching of organic nanomaterials by rare gas discharge) , Oxygen addition by oxygen plasma, local oxidation, surface nitridation by nitrogen plasma, etc.), and chemical reaction during plasma treatment can be traced directly with a mass spectrometer while observing ions.

However, the ion analyzer 60 is not necessary for the purpose of material processing, processing, synthesis, etc., and the inner tube 11 C does not need to be a tube. .

Second embodiment

The second embodiment is particularly suitable for ion analysis of a gaseous sample. The basic configuration is shown in Fig. 11. The difference from the first embodiment shown in Fig. 1 is that the outer tube 12E is basically used as the sample supply tube. The same cylinder 17 as shown in FIG. 3 is provided at the tip of the sample supply pipe 12E. You can make a hole in this cylinder 17 to escape the helium gas described later.

A sample suction tube (including a sample suction tube, which may be called a sample supply tube) 14 is connected to the proximal end side of the sample supply tube 12E. The sample suction tube 14 is provided with a suction pump 41, a dust removal filter 42, and a water vapor removal filter (which may be replaced with a desiccant) 43. The sample suction tube 14 is supplied with helium gas from the branch tube 14A as the discharge gas in order to enhance and promote the stability of the barrier discharge. Nitrogen and oxygen in the atmosphere sucked together with the sample gas can also become discharge gases, so it is not always necessary to supply helium gas.

The tip 14 a (14 b, 14 c) of the sample suction tube 14 (the suction nozzle part ahead of the suction pump 41) is inserted into the subject package 44, for example, as shown in FIG. . By making the tip 14a into an elongated tube (suction nozzle), the packed gas can be sucked and analyzed by inserting the tube into the interior without unpacking. In addition, the outflow gas from the gas chromatograph It can also be used as a highly sensitive ion detector for gas chromatography. As shown in Fig. 13, exhalation may be aspirated at the tip 14b, or air can be aspirated at the tip 14c as shown in Fig. 14 for atmospheric monitoring.

In any case, the sucked gas sample is guided to the tip of the sample supply tube 12 E, ionized by the Parrier discharge generated here, and guided to the analyzer 60 by the sample tube 11 to be ionized. Be analyzed.

As described above, the inside of the mass spectrometer 60 is kept in a vacuum, and the sample tube 11 also has a negative pressure. Therefore, using this negative pressure, the sample gas is supplied to the sample suction tube 14, the sample supply tube 12E. Can also be sucked through. In this case, the suction pump 41 is not necessary. Filters 42 and 43 can also be omitted in some cases. As shown in Fig. 7, the inner pipe of the double pipe section 10 may be the sample supply pipe and the outer pipe may be the sample pipe.

Example 3

In the third embodiment, two electrodes are arranged on one side of a dielectric plate. Referring to Figs. 15 and 16, the electrode support 8 is formed of a dielectric or insulator. Since this electrode support 8 is cylindrical (or may be prismatic), a thin (eg 0.5 rara) ion sampling pore 8 A penetrates the support 8 at the center of the circle. Is formed. The lower surface 8 B of the support 8 (the-side, the lower side in the figure) is formed into a conical concavity that matches the shape of the sampling orifice 65 of the mass spectrometer 60. Yes. When the support 8 is attached to the sampling orifice 65, the central pore 8A coincides with the ion introduction hole 65a of the orifice 65.

The upper surface (the other surface) of the electrode support 8 is flat, and two electrodes (metal) 23 are sandwiched between the pores 8 A on this surface (slightly spaced than the thickness of the dielectric plate 9 A described later). It is buried with a large gap). These electrodes 23 are supported by the support Connected to the power supply 30 by a conductor pattern or via 24 formed (provided) (or provided inside or provided) on the upper surface of 8 and AC voltage between the two electrodes 23 Is applied.

A circular dielectric plate (for example, 0.5πιηι) 9 A is placed (fixed, attached) on the upper surface of the electrode support 8. This dielectric plate 9 A also has pores

A pore 9 a corresponding to 8 A is opened.

Further, on the dielectric plate 9 A, a cylindrical sample mounting table (mounting cylinder or mounting wall) and surrounding cylinder (wall) (hereinafter referred to as mounting cylinder) 7 are pores centered on the pore 9 a.

9 Placed around (fixed, mounted). The sample mounting cylinder 7 is not limited to a cylindrical shape, but may be a rectangular tube shape or other shapes. On the peripheral wall of the sample tube 7, discharge gas inlets 7 a and 7 b are opened at positions facing each other. A discharge gas such as helium is introduced into the cylinder 7 from the inlet 7a and discharged from the outlet 7b.

When an AC voltage is applied between the two electrodes 23, a discharge current flows through the dielectric plate 9A in the thickness direction, and a Parrier discharge is generated in the mounting cylinder 7, that is, the dielectric plate 9A. Creeping discharge occurs on the surface of the surface. Placing or holding the sample or object over the top opening of the mounting cylinder 7 desorbs and ionizes the trace components from the sample or object. The generated ions are introduced into the analyzer 60 內 through the pores 9a and 8A and the ion introduction hole 65a and analyzed. In this way, it is possible to directly analyze biological tissues such as animal skin, other samples, and objects. This modified example is versatile because it does not matter what the sample is. By supplying the discharge gas into the mounting cylinder 7, a barrier discharge is generated efficiently and stably.

In the structure of this embodiment, the surface where the AC voltage is applied to the dielectric plate and the surface where the barrier one discharge is generated are separated on the opposite side, so that a space for generating ions (barrier one discharge space) is provided. Without being exposed to high voltage Safe operation is possible in the collection. In addition, if the distance between the two electrodes and the size of the electrodes are reduced, creeping discharge can be generated locally on the opposite side of the dielectric plate, so that it is possible to obtain an imaging image of the sample. .

Finally, demonstration data showing that various substances can be detected using the ionization analyzer and method of the above-described embodiment will be described with reference to FIGS.

Fig. 17 shows the result of analyzing the vapor component of a solution of 3, 4-dinitrotoluene 1 rag / ral dropped onto a cotton swab as an example of explosives using the apparatus shown in Fig. 1. Is shown. Helium (flow rate 1 L / rain) was used as the discharge gas.

Figure 18 shows the results of analysis of hexane vapor as an example of a nonpolar compound using the apparatus shown in Fig. 11. Argon was used as the discharge gas.

Fig. 19 shows the results of analysis using an apparatus shown in Fig. 4 as an example of agrochemicals by dropping a solution of methamidophos in ethyl acetate (lOngZpl) onto filter paper.

Thus, it can be seen that various substances can be analyzed with high sensitivity.

Claims

The scope of the claims

1. An AC voltage is applied between at least two electrodes, causing a barrier discharge to occur in the space including the surface of the dielectric placed across the discharge current path, and the position exposed to the generated barrier discharge. Supplying the sample to be analyzed to

Introducing the sample ion resulting from exposure to the barrier discharge to the analyzer,

An ionization analysis method comprising:

2. The ionization analysis method according to claim 1, wherein the sample ion is guided to the analyzer by a sample tube arranged so that one end faces the space where the barrier discharge occurs.

3. The ionization analysis method according to claim 1, wherein the gas for discharge is supplied by a gas supply pipe arranged so that one end faces the space where the barrier discharge occurs.

4. The ionization analysis method according to claim 1, wherein the sample gas is supplied by a sample supply pipe arranged so that one end faces the vicinity of the space where the barrier discharge occurs.

5. Either the sample tube, the discharge gas supply tube, or the sample supply tube arranged so that one end faces the space where the barrier discharge is generated, including the surface of the dielectric, is connected to the first electrode. And a flat plate-like second electrode is disposed on the opposite side of the surface of the dielectric, and an AC voltage is applied between the first electrode and the second electrode. The ionization analysis method described in item 1.

6. Arranging the two electrodes so as to sandwich the dielectric, or arranging the two electrodes on the opposite side of the surface of the dielectric. The ionization analysis method according to paragraph 1 of the above.

7. The two electrodes are arranged on the opposite side of the surface of the dielectric, and a sample mounting table or a surrounding cylindrical body is placed at a position facing the two electrodes on the surface of the dielectric. The ionization analysis method according to claim 1, which is arranged.

8. Apply an alternating voltage between at least two electrodes to generate a Parrier discharge in the space containing the surface of the dielectric placed across the discharge current path, and

Supplying the target sample to a position exposed to the generated barrier discharge.

9. Apply an alternating voltage between at least two electrodes to create a barrier discharge in the space containing the surface of the dielectric placed across the discharge current path, and

Supplying the material to be processed to the position exposed to the generated barrier discharge,

A chemical treatment method comprising:

10. A dielectric and at least two electrodes to which an AC voltage is applied are provided, and the surface of the dielectric faces in or near the space to which the sample to be analyzed is supplied. The dielectric is disposed across the discharge current path of the barrier discharge so that a barrier discharge is generated in a space including the surface of the dielectric by applying a voltage.

In addition, it has an ion introduction path that guides the sample ions generated when the sample to be analyzed is exposed to barrier discharge to the analyzer.

Ionizer.

11. The ion introduction path according to claim 10, wherein the ion introduction path is a sample tube disposed so that one end thereof faces a space where a barrier discharge occurs. Device.

12. The ionization apparatus according to claim 10, further comprising a gas supply pipe that is arranged so that one end faces a space where a barrier discharge occurs, and supplies a discharge gas.

13. The ionization apparatus according to claim 10, further comprising a sample supply pipe that is arranged so that one end faces the space where the barrier discharge occurs, and supplies a sample gas.

14. Equipped with a sample tube as the ion introduction path that guides the ions of the sample to the analyzer and a gas supply tube that supplies the discharge gas. These sample tube and gas supply tube are formed in a double structure. The ionization device according to claim 10, wherein one end of each of these tubes is arranged so as to face a space near where a barrier discharge occurs.

15. It has a sample tube as the above-mentioned ion introduction path that guides the sample ion to the analyzer and a sample supply tube that supplies the sample gas. These sample tube and sample supply tube are formed in a double structure, The ionization apparatus according to claim 10, wherein one end of each of the tubes is arranged so as to face the vicinity of a space where a barrier discharge occurs.

16. The ionization apparatus according to claim 10, wherein a cylinder, a wall, a pipe, or a guide is provided to surround a space where a barrier discharge occurs and its vicinity.

17. Sample tube in which the first electrode of the above two electrodes is arranged so that one end faces the vicinity of the space that generates the barrier discharge, including the surface of the dielectric, and the discharge gas supply Either a tube or a sample supply tube, and the second electrode is a flat electrode disposed on the opposite side of the surface of the dielectric, and between the first electrode and the second electrode The ionization device according to claim 10, wherein an AC voltage is applied.

18. The above two electrodes are placed so as to sandwich the dielectric. The ionization apparatus according to claim 10, wherein the two electrodes are arranged on a side opposite to the surface side of the dielectric.

19. The two electrodes are arranged on the side opposite to the surface side of the dielectric, and the sample mounting table or the surrounding cylindrical body is located at a position facing the two electrodes on the surface of the dielectric. The ionization device according to claim 10, wherein:

20. an electrode support made of an insulator provided with an ion introduction path;

Two electrodes embedded in the electrode support across the ion introduction path, a dielectric disposed so as to cover the electrode, and a hole leading to the ion introduction path;

An ionization device comprising:

21. An ionization analyzer comprising the ionizer according to claim 10 or 20 and a mass spectrometer to which ions are introduced.