JPH03165239A - Icp analyzing apparatus - Google Patents

Abstract

PURPOSE:To rapidly remove impurities during analysis without stopping the device by disposing an inducing means for inducing filamentary plasma from a plasma flame on the outer side of carrier gas flow passage pipe systems used for carrying of a sample into the plasma flame. CONSTITUTION:An electrode 9 connected to a high-voltage generator 11 is provided as the means for inducing the filamentary plasma from the plasma flame on the outer side of the inside pipe 2 near the sample introducing pipe 8a. Namely, this inducing means is disposed on the outer side of the carrier gas flow passage pipe systems 2, 8a used for carrying the sample into the plasma flame, by which the filamentary plasma induced by the inducing means from the plasma flame and made to exist within the carrier gas flow passage pipe systems 2, 8a is brought into reaction with th impurities sticking and remaining on the inner side of the carrier gas flow passage pipe systems 2, 8a by the high temp. and the reactivity thereof. The impurities are thus re moved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an ICP analyzer capable of performing ICP (high frequency inductively coupled plasma) emission spectrometry or ICP mass spectrometry. This invention relates to an ICP analyzer that improves the removal of contamination from a carrier gas flow pipe system used for carrying in samples.

(Prior Art) In recent years, ICP analyzers capable of performing ICP emission spectrometry or ICP mass spectrometry have been widely used as an extremely sensitive analysis method.

In this ICP analyzer, a sample is introduced into a plasma flame formed in a plasma torch 2 via a carrier gas flow pipe system connected to a sample introduction chamber.

In this type of ICP analyzer, during analysis.

Impurities tend to adhere and remain inside the carrier gas flow path pipe system, and these impurities increase the background,
Since it interferes with high-sensitivity analysis, it is necessary to remove it as appropriate.

Conventionally, when removing these impurities, the ICP analyzer was stopped, the plasma torch was taken out from the apparatus, and the inner wall of the carrier gas flow path pipe system of the torch was cleaned with an acid such as aqua regia or hydrofluoric acid.

(Problems to be Solved by the Invention) In other words, the work of removing obtuse substances in conventional ICP analyzers has problems such as the need to stop the equipment and the fact that one work is complicated and takes a long time. Ta.

The present invention has been made in consideration of the problems of the prior art, and is an ICP analysis method that can quickly remove impurities that adhere and remain inside the carrier gas flow R pipe system during analysis without stopping the apparatus. The purpose is to provide equipment.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for controlling plasma formed on a plasma torch through a carrier gas flow pipe system connected to a sample introduction chamber. ICP where the sample is introduced into the flame
The gist of the analyzer is to include an attracting means that is provided outside the carrier gas-aBg system used to carry the sample into the plasma flame and that attracts filamentary plasma from the plasma flame.

(Function) - According to the present invention which takes the means described in F, the following effects are achieved. That is, by arranging an attracting means for attracting filamentary plasma from the plasma flame outside the carrier gas flow path pipe system used for carrying the sample into the plasma flame, carriers are attracted from the plasma flame to the attracting means. A filamentary plasma exists within the gas flow pipe system.

Due to its high temperature (about 3000°C) and reactivity,
Since it is possible to react with and remove impurities that remain attached to the inside of the carrier gas flow path pipe system, the impurities can be quickly removed during analysis without stopping the apparatus.

(Embodiment) Hereinafter, an embodiment of the CP analyzer according to the present invention will be described with reference to FIG. 1, which shows a cross section of the main part of the ICP plasma torch section of this analyzer.

The plasma torch 1 includes an inner pipe 2 (part of a carrier gas flow path pipe system to be described later) used for carrying a sample into the plasma flame.
, an intermediate tube 3 and an outer tube 4 for supplying argon gas toward the plasma flame. A coil 5 to which high frequency waves are applied is disposed on the outer periphery of the outer tube 4 near the upper opening. Further, at the lower proximal end of the inner tube 2, there is attached a sample introduction tube (sample introduction chamber>8a) in which a nebulizer 8 for atomizing the sample solution 7 is installed, and together with the inner tube 2, a carrier gas flow RW - It constitutes a system.

Further, on the outside of the inner tube 2 next to the sample introduction tube 8a, an electrode 9 connected to a high pressure generator 11 is provided as a means for attracting filamentary plasma (described later) from the plasma flame. Note that the means for attracting this filamentary plasma is not limited to the electrode 9, but any means that generates an electric field or magnetic field of a required magnitude, such as a magnet that generates a magnetic field, may be used. Although the arrangement position of 9 is not limited to a specific position,
In order to remove impurities over the entire area, it is desirable that the position be as low as possible in the inner tube 2.

Further, it is preferable to RIIH the filamentary plasma by changing the voltage generated by the high voltage generator 11.

In an ICP analyzer having such a configuration, when performing an analysis, the intermediate tube 3. Argon gas is passed through the outer tube 4 and high frequency waves are applied to the coil 5 to induce a plasma flame 6.

Then, the sample solution 7 is atomized by a nebulizer 8 and introduced into the plasma flame 6 through the inner tube 2. In this process, the target element in the sample introduced into the plasma flame 6 is
Because it is excited and emitted or ionized, the emission intensity of the target element is measured using a monochromator (not shown) based on ICP emission spectrometry, or the ion intensity of the target element is measured based on ICP mass spectrometry. be.

As this type of analysis continues, the sample solution 7 will adhere to the inner wall of the inner tube 2. When it is confirmed that the background has increased due to this adhered sample solution 7, the inner tube 2
A high voltage generator 1 is connected to the electrode 9 provided at the bottom.
1. Apply high voltage.

Filamentary plasma 10 from plasma flame 6 to electrode 9
induce. Due to this induction, the filamentary plasma 10 existing in the inner tube 2 can react with and remove impurities that adhere to and remain on the inner wall of the inner tube 2 due to its high temperature and reactivity, so that the filamentary plasma 10 existing in the inner tube 2 can be removed while the apparatus is in operation (during analysis). However, impurities can be removed quickly. Also, the electrode 9 is connected to the inner tube 2.
Since the electrodes 9 are not provided inside the inner tube 2 but are provided outside the inner tube 2, the inside of the inner tube 2 is not contaminated by the electrodes 9.

As this removal effect, silicon (Si) and boron (
The background (hereinafter referred to as BG) measured after 50 analytical measurements using B), and the BG measured after removing impurities with filamentary plasma 10 after this measurement, were compared to the background after cleaning with acid from a plasma torch. Along with BG measurements.

As is clear from Table 1, the IC of this example
It can be seen that when impurities are removed by filamentary plasma 10 using a P analyzer, the background is reduced to 1/10 or less.

(The following is a blank space) Table 1 [Effects of the Invention] As explained above, in the ICP analyzer according to the present invention, the attracting means for attracting filamentary plasma from the plasma flame is used to carry the sample into the plasma flame. By disposing the carrier gas flow path outside the carrier gas flow path pipe system, the filamentary plasma that is attracted from the plasma flame by the attracting means and exists within the carrier gas flow path pipe system, due to its high temperature and reactivity, can Since impurities that adhere to and remain inside the tube system can be removed, the impurities can be quickly removed during analysis without stopping the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an ICP plasma torch section of an ICP analyzer according to the present invention. 1... Plasma torch 2... Inner pipe (part of carrier gas flow path pipe system) 6...
Plasma flame 7...Sample solution 8a...Sample introduction tube (sample introduction chamber)

Claims (1)

[Claims] Via a carrier gas flow path pipe system connected to the sample introduction chamber,
An ICP analyzer in which a sample is carried into a plasma flame formed on a plasma torch, comprising an attracting means provided outside the carrier gas flow pipe system to attract filamentary plasma from the plasma flame. An ICP analyzer characterized by: