JPS5878359A - Ion generator - Google Patents

Abstract

PURPOSE:To increase the produced amount of sample ions greatly, and improve the sensitivity of a mass spectrograph or an ionization detector exceptionally from that of the conventional one by fixing a sample to a holding member having many projections, and applying a high voltage to said holding member. CONSTITUTION:Since a sample is fixed to and held by a member having a number of pin-line projections 21, to which a high voltage is applied, an exceptionally strong electric field exists around the projections 21, and the sample surface is exposed to the strong electric field. Therefore, molecules of the sample, after receiving the energy of Ar* (11.55eV or 11.72eV) by touching Ar*, are immediately ionized, and rapidly eliminated from the surface due to the strong electric field. As a result, a remarkably increased amount of sample ions can be eliminated by the application of the high voltage, compared to the amount of sample ions eliminated when the same amount of Ar* is applied without any application of high voltage. In addition, in this invention, since the sample is fixed to and held by the many pin-like projections 21, the surface area of the sample (the contact area between Ar* and the sample) is increased, and the produced amount of sample ions is increased in this connection too.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion generating device suitable for use in mass spectrometers, ionization detection devices, etc. We proposed a new ion generation method in which an excited species is applied to a sample and the sample is ionized. This proposed method is described in detail in Japanese Unexamined Patent Publication No. 55-9107 I, and can be implemented using the apparatus t configuration roughly illustrated in FIG. In FIG. 1, reference numeral 1 denotes a glass tube through which a carrier gas such as argon is introduced into the interior from an inlet 2. One end of the glass tube 1 is sealed by an insulator 6I, and the glass tube 1 is sealed by an insulator 6I. The needle pole 4 is inserted into the glass tube. At the other end of the glass tube, an opposing W1 pole 5 facing the upper needle brazing electrode 4 is housed, and the opposing I! lt pole 5 followed by net-pole 6. A ring 9゜10 between which the repeller electrodes 7 and 8 serve both as insulation and airtightness.
．． 11 and are arranged in this order.

12 is a sample.

Then, a corona discharge is caused between the needle electrode 4 and the counter electrode 5 to create argon ions Ar+, C- and excited argon atoms Ar (excited S), of which Ar and e- are generated by the electrode 6. The feature of this proposed method is to remove only the Ar and ionize the sample using the excitation (internal) energy of the Ar.
ta+ liquid sample can be directly ionized under atmospheric pressure, (b
) In particular, when argon is used, most organic compounds can be ionized, and water, air, etc. are hardly ionized, so samples can be handled freely in the air. (C) Since ionization is performed at atmospheric pressure, strict airtightness is required. The present invention aims to further improve the proposed method, which has such excellent points, and in particular, it By applying a high voltage to each holding member, the amount of sample ions produced is dramatically increased, and the sensitivity is improved by an order of magnitude higher than before. The purpose of this invention is to provide ion generation technology that can improve the difference. The present invention will be explained in detail below based on the drawings.

- Figure 2 shows an ion generator according to the present invention with a quadrupole m
A cross-sectional view showing an embodiment used as an ion source of a Teiden analyzer, FIG. 3 is a cross-sectional view taken along the line I-I, and the same densification Ij! as in FIG. 1 is shown. The search terms are marked with the same symbol. In this implementation, in order to ensure the removal of argon ions Ar and electrons e-, one more net polarization 16 was placed between the net ion 6 and the repeller ridge 7, and an appropriate potential was applied. In addition, a ring 141 has been added. Also, the ring 11 has an exhaust port 15.
When the sample holder 16 is provided, a sample holder 16 including a member having a large number of protrusions is pushed in. The holder 16 has a glass base 17. There are two supports that pass through the entire base.18
, 19 and tungsten 4I20 stretched between the sections.
The sample liquid is adhered and held on needle-like protrusions (whiskers: for example, needle-like crystals of silicon or carbon) 21 that have grown in large numbers on the surface of the tungsten wire 2u. A high voltage of AIV to 100 V is applied to the above tungsten 4I2U base by the power supply 22, and the solder #2 is applied as needed.
6, electrical heating can be performed.

A quadrupole mass spectrometer @ 29 equipped with lens magnetic poles 24 and 25, a quadrupole pole 26, an ion detector 27, and a vacuum pump 28 is connected to the rear stage 1 of the primary ring 11. -This is high vacuum '1! A pinhole 60 is provided with a pinhole 60 having a uniform conductance capable of maintaining a pressure difference with the analyzer. The electrode 61 is connected to the ring 32. This makes it insulated from the surroundings, and an appropriate voltage can be applied from VT #66.

With the above-mentioned configuration, the inner heat of the ion generator is connected from the inlet 2 to the glass f1. Ring 9, ILI.

A steady flow of argon gas at 1 atm@degrees is formed which escapes to the exhaust port 15 through the opening 14. When a high voltage of, for example, 3KV4!4tL is applied to the needle fIL4, a corona discharge occurs between it and the magnetic pole 5, and due to this discharge, the ions Ar, [ A child e- and an excited state argon atom Ar F are generated. The reaction is approximately shown by the following equation.

Release area Ar--→Ar++e-... (1) Ar LAr
*-, **** L2) A produced by the reaction of formula (2)
r1 indicates a metastable state (excitation energy 11-55 eV and 11.72 eV) 0 This state of person r has a long life (
(after 10 sec J:), even if it collides with an Ar atom, the total number of Ar remains unchanged as only the resonance energy transfer occurs according to the following equation.
r + Ar book ------131 Ar+ generated from one corona blast in this seedling.

e- and Ar are stationary tlLl (ride) and move toward the sample holder, but Ar and e- with am cannot pass through the sft poles 6 and 16 given an appropriate potential and are removed. , Ar* which has no charge in the ring 11
only will be reached. When this Arn comes into contact with the sample, the compound -1jl1M, which has an ion specific energy lower than the excitation energy (11.55 eV or 11.72 eV) of Ar', is completely ionized according to the following equation.

Ar + M-chi Ar 10M++ e @ 11@
141 In the present invention, at this time, the sample is attached and held by a member having a large number of needle-like protrusions, and a high voltage is applied to this. Therefore, the sample molecules that receive the energy of Ar' (11.55 eV or 11.72 eV) through contact with Ar* are immediately ionized and ionized by this strong electric field. Since it is quickly desorbed from the surface, the A of the same electric current is lower than when high voltage is not applied.
r'', the amount of sample ions desorbed can be dramatically increased60 In addition, in the present invention, since the sample is attached and held by a large number of needle-like protrusions, the surface M of the sample (i.e., Ar'
The area of contact with
~lO times the cloud increases by ζ6, thus the sensitivity increases by l゛02~10''
It was also confirmed that even difficult-to-volatile samples can be effectively ionized.
(7) Increase the amount @: It was confirmed that you can get about 1500
If it exceeds V, not only the sample molecules but also the surrounding argon excited species will be ionized by the strong electric field, giving a significantly larger background current than the sample ions, so C is preferable; in fact, clouding is ioo.

The range from V to tsoo y is the breakthrough voltage.

Conventionally, attempts have been made to increase the amount of sample ions generated by heating the sample, but heating is not necessarily necessary in the present invention, which can dramatically increase the amount of ions by applying A@ pressure. Therefore, even if the sample is thermally unstable, it is possible to ionize the sample without forming a wave layer. It goes without saying that it can be increased, and there is no need to make the JM & et al. The strong force and the argon gas flow flowing from near the sample toward the pinhole 60 - a powerful analysis! This example is an example of introducing positive ions into a mass spectrometer. However, if negative ions are to be analyzed, tungsten wire 20. Libera electric shock 7 and pin: The polarity of the voltage applied to the pinhole electrode 61 may be reversed.

The present invention can be applied to the above-mentioned embodiments (without limitation (many modifications are possible). For example, if the present invention is applied to an ionization detection system, the ion collector electrode is placed close to the sample, and the ion collector electrode is placed close to the sample, The collected sample ions can be detected by collector-parked tC collection.In the above-mentioned embodiment, one tungsten wire with many needle-like protrusions attached to it or one sample attached to it, or a large number of As long as the part l has a protrusion, the seal can be shaped into a plate or a coil.

In addition, if a pipe connected to a separation column of a liquid chromatograph is inserted into the ring 11 and the sample liquid flowing out is dripped or continuously attached to the needle-like protrusion, the liquid chromatograph and the liquid analysis can be performed. It is possible to connect the device online.Also, in the above-mentioned embodiment, the excited species Ar was generated using one-time, one-time operation, but it is also conceivable to use light or other radiation. The carrier gas is also limited to one argon fltl.
l of gas can be used.

In addition, in this example, the charged particles (Ar+, e) were removed from the 6th and 161st electrodes, but an electrode with a hole in the center could be used, and in order to remove the Tsubato particles. It is also possible to apply a magnetic field or a magnetic field in the direction of direct combustion to the gas flow.Additionally, there is a method of applying the excited species to the sample from a direction that is perpendicular to the plane of the paper.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a mounting structure for explaining the proposed method, Fig. 2 is a cross-sectional view showing the structure of an embodiment of the present invention, and Fig. 3 is a cross-sectional view taken along line I-I. 1 pole, 5: opposite pole, 6, 7: Toshi Aminawate, 16: sample holder, 20: tungsten wire, 21: needle-like projection, 22 Nikkegen, 29: @ Ro analysis device, 60: pinhole.

Claims (1)

[Claims] L: excitation means for exciting a carrier gas; charged particle removal means disposed in a passage through which charged particles and excited species generated by the excitation are guided; and excitation that has passed through the removal means. A member having a large number of protrusions arranged at positions through which the seeds pass, and means for applying a high voltage to the member, a sample is attached to the member that extends through the large number of protrusions, 2. The apparatus according to claim 1, wherein the ionized sample ions are introduced into the mass spectrometer through the ion generator O a excitation sI, which is characterized in that the excited species is applied to the ion generator for ionization. & The apparatus according to claim 1, wherein sample ions ionized from the excited species 1 are guided to the ion collector. The device according to claim 1, wherein the excitation means excites the carrier gas by a corona group.