JPH0545969Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nebulizer that is most suitable for use in a high frequency inductively coupled plasma ion source.

[Prior Art] Recently, a high frequency inductively coupled plasma mass spectrometer that combines a high frequency inductively coupled plasma ion source and a mass spectrometer has been developed and put into practical use.

Such a high frequency inductively coupled plasma mass spectrometer uses plasma to ionize a liquid sample,
The generated ions are introduced into a mass spectrometer via an interface and subjected to mass analysis. At this time, in order to ionize the sample with plasma, a third
It is necessary to use a nebulizer as shown in the figure to atomize the liquid sample and spray it into the plasma.

In the figure, reference numeral 1 denotes an outer pipe, one end of which is narrowed and has a spout hole 2 formed at the tip, and the other end is closed by a bottom 3. Reference numeral 4 denotes an inner pipe disposed approximately concentrically inside the outer pipe, one end of which is placed close to the spout hole 3, and the other end fixed to the bottom portion 3. Further, this inner pipe is configured to communicate with a sample supply pipe 5 fixed to the outside of the bottom portion 3. Reference numeral 6 denotes a gas introduction pipe for ejecting any gas from the ejection hole 2 through the gap S formed between the outer pipe 1 and the inner pipe 4. Further, each of these members is usually constructed by integrally molding quartz glass with excellent heat resistance.

Now, with the argon gas introduced from the gas introduction pipe 6 passing through the gap S and being ejected from the ejection hole 2 of the outer pipe 1, if the sample liquid is introduced from the sample supply pipe 5 into the inner pipe 4, the sample liquid will flow through the ejection hole. The argon gas is atomized by the argon gas ejected from 2 and ejected into a plasma torch (not shown), so that it is ionized.

On the other hand, nebulizers used in high-frequency inductively coupled plasma ion sources are designed to prevent the temperature of the plasma from decreasing when the sample liquid is atomized and introduced into the plasma. It is desired that the droplets be small. In order to reduce the size of these droplets, it is necessary to increase the flow rate of the gas ejected from the opening hole 2 of the outer pipe 1. Here, in order to increase the gas flow rate, it is necessary to take the following measures.

(1) Inner and outer pipes 1 and 4 at the gas jetting part
To minimize the gap G formed between the two.

(2) The position of the tip of the inner pipe can be adjusted back and forth with respect to the outlet hole of the outer pipe.

(3) Reduce the inner diameter and outer diameter of the inner pipe and the inner diameter of the jet hole in the outer pipe.

[Problem that the invention aims to solve] By the way, in conventional nebulizers, the outer and inner pipes are integrally molded, so it is extremely difficult to implement the above-mentioned measures to reduce the diameter of the droplets of the atomized sample liquid. There are limits to what you can do.

Therefore, the present invention has been made in view of this point, and it is an object of the present invention to provide a nebulizer that can reduce the size of droplets of atomized sample liquid.

[Means for Solving the Problems] In order to achieve the upper air purpose, the nebulizer for a high frequency inductively coupled plasma ion source of the present invention has a bottomed outer pipe having an ejection hole at the tip, and a nebulizer that is substantially concentric with the outer pipe. a guide cylinder arranged in a shape and attached to the bottom of the outer pipe so that its inside communicates with the outside; an inner pipe disposed close to the inner pipe, means for fixing the inner pipe to the outer pipe, and a gas supply means for ejecting gas from a nozzle hole through a gap between the outer pipe and the inner pipe. , the sample from the inner pipe is atomized by gas ejected from the nozzle hole and sprayed into the plasma.

Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

[Example] FIG. 1 is a sectional view showing an example of a nebulizer according to the present invention, and the same numbers as in FIG. 3 indicate the same components.

In this embodiment, the guide cylinder 7 is formed integrally with the outer pipe 1 along substantially the central axis of the outer pipe 1, and the inner pipe 4 is movably inserted into the guide cylinder 7. Features. As the inner pipe, a fused silica pipe coated with polyimide is used. The inner pipe 4 is taken out from the outer pipe 1 and connected directly or via an arbitrary connector to a bottle containing a sample liquid (not shown).
Further, this inner pipe is fixed to the protrusion 1a of the outer pipe 1 via a rubber stopper 8.

In this way, the three requirements mentioned above can be satisfied. That is, the outer and inner pipes 1,
4 and 4 can be formed separately instead of integrally as in the past, the gap G between both pipes at the 2 parts of the ejection hole can be easily reduced, and the inner diameter of the inner pipe and the outer diameter can be easily reduced. Both the diameter and the diameter of the ejection hole of the outer pipe can be made small with high accuracy. Further, since the inner pipe can be moved along its axial direction, the tip of the inner pipe can be set at an optimal position with respect to the ejection hole of the outer pipe. As a result, the flow rate of the gas ejected from the ejection hole 2 can be increased, so that a mist-like sample liquid with very small droplets can be introduced into the plasma, and an increase in the temperature of the plasma can be suppressed.

It should be noted that the above description is an example of the present invention, and many variations can be considered in its implementation. For example, in the above embodiment, the inner pipe 4 is
Although the rubber stopper 8 is used to directly fix the rubber stopper 8, the present invention is not limited to this, and the rubber stopper 8 may be fitted into a nut 9 screwed onto the protrusion 1a of the outer pipe as shown in FIG. By doing so, the position of the tip of the inner pipe relative to the outer pipe can be accurately and easily adjusted simply by operating the nut.

[Effects of the invention] As detailed above, according to the invention, the outer and inner pipes are not integrally molded as in the past, but are formed separately, which makes it possible to satisfy the above three requirements. You can get a nebulizer that can. As a result, the flow rate of the gas ejected from the ejection hole can be easily increased, so that a mist-like sample liquid with very small droplets can be introduced into the plasma, and an increase in the temperature of the plasma can be suppressed.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing an example of a nebulizer according to the present invention, and FIG. 3 is a diagram for explaining a conventional example of a nebulizer. 1...Outer pipe, 2...Ejection hole, 3...Bottom, 4...Inner pipe, 5...Sample supply pipe,
6...Gas introduction pipe, 7...Guide tube, G...Gap, S...Gap.

Claims (1)

[Scope of utility model registration request] a bottomed outer pipe with a spout hole at the tip;
a guide cylinder disposed approximately concentrically with the outer pipe and attached to the bottom of the outer pipe so that its interior communicates with the outside; a guide cylinder disposed movably inside the guide cylinder; an inner pipe disposed close to the nozzle hole of the inner pipe; a means for fixing the inner pipe to the outer pipe; and a means for ejecting gas from the nozzle hole through a gap between the outer pipe and the inner pipe. 1. A nebulizer for a high-frequency inductively coupled plasma ion source, comprising: a gas supply means, wherein the sample from the inner pipe is atomized and atomized into the plasma by the gas ejected from the nozzle hole.