JP3206216B2 - ICP emission spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ICP (high frequency inductively coupled plasma) emission spectrometer and, more particularly, to an improvement in a sample introduction system.

[0002]

2. Description of the Related Art Generally, a sample introduction system of an ICP emission spectrometer is shown in FIGS.

First, in the sample introduction system shown in FIG. 3, the liquid sample S in the sample container 18 is sprayed toward the inside of the spray chamber 27 by the nebulizer 25 of the spray type to be atomized. The sample is introduced into the plasma torch 30 having a triple tube structure via the vial, and the atomized sample is excited by the high frequency magnetic field generated by the high frequency coil 22 to emit light for analysis.

[0004] Further, the sample introduction system shown in FIG. 4 is capable of obtaining a sample aerosol having a smaller particle diameter than the nebulizer 25 of the above-mentioned spray type, and is capable of obtaining a sample aerosol.
This is an introduction system using. The ultrasonic nebulizer 3 is composed of a nebulizer main body 13 for atomizing the liquid sample S by ultrasonic vibration and a desolvating section 14, and a spray chamber 27
The liquid sample S supplied to the inside is atomized by the vibration of the ultrasonic vibrator 16 and sent out to the desolvation section 14 together with the carrier gas. Then, the solvent is removed by cooling the mixture into the plasma torch 30.

Further, the sample introduction system shown in FIG. 5 is an introduction system having a hydride generator 2 for reducing an element in a liquid sample S to convert it into a gaseous hydride and then introducing the gaseous hydride to a plasma torch 30. is there.

When the liquid sample S, the hydrogenating agent, and the carrier gas are introduced together into the joint 5 of the hydride generator 2, most of the liquid sample S and the hydrogenating agent react when passing through the reaction tube 6. As a result, a hydride is generated, and a part of the unreacted hydrogenating agent and the sample liquid S are directly introduced into the gas-liquid separation chamber 8. The gas-liquid separation chamber 8 separates the hydride M obtained in the reaction tube 6 from the reaction residual liquid L and stabilizes the analysis sensitivity. Is transmitted to the plasma torch 30. An S-shaped pipe 9 for adjusting the liquid level and one end of a quick discharge pipe 10 for discharging the residual reaction liquid at the time of exchanging the sample liquid are connected to the lower part of the gas-liquid separation chamber 8 respectively. The other ends of the and the rapid discharge pipe 10 are both open to the drain tank 11.

[0007]

However, in the sample introduction system using the nebulizer 25 of the spray type shown in FIG. 3 or the ultrasonic nebulizer 3 shown in FIG. 4, As,
Elements such as Se, Sb, and Bi cannot be analyzed due to insufficient sensitivity. Therefore, in the analysis of such elements, the elements are reduced by a sample introduction system using a hydride generator shown in FIG. Must be converted to hydrides for analysis,
Conversely, since elements such as Cd, Fe, Zn, and Cr cannot be converted into gaseous hydrides, they need to be analyzed using a nebulizer of a spraying method or a sample introduction system using an ultrasonic nebulizer.

Therefore, in the conventional ICP emission spectrometer, when analyzing a sample containing both the above-mentioned elements such as As, Se, Sb and Bi and the elements such as Cd, Fe, Zn, Cr, etc. It is necessary to perform the analysis twice by replacing the introduction system, which requires much time for the analysis, and in the meantime, there is a problem that a large amount of argon gas or the like is consumed and the analysis cost is high.

The present invention has been made in view of the above points, and has as its object to analyze many kinds of elements at the same time without replacing the sample introduction system.

[0010]

According to the present invention, in order to achieve the above object, a hydride generator for reducing an element in a liquid sample to convert it into a hydride, and a nebulizer for atomizing the liquid sample are provided. And the hydride and the carrier gas from the hydride generator are supplied to the nebulizer as a carrier gas, and the hydride and the atomized sample from the nebulizer are introduced into the plasma torch.

[0011]

According to the above construction, the hydride and the carrier gas from the hydride generator are supplied as a carrier gas to the nebulizer for atomizing the liquid sample, and the hydride and the atomized sample from the nebulizer are converted into a plasma torch. Therefore, it is possible to simultaneously analyze elements such as As, Se, Sb, and Bi, which are insufficient in sensitivity in a sample introduction system using a nebulizer, and elements such as Cd, Fe, Zn, and Cr that cannot be converted into gaseous hydrides. .

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing the entirety of an ICP emission spectrometer according to an embodiment of the present invention, and portions corresponding to the above-mentioned conventional example are denoted by the same reference numerals.

The ICP emission spectrometer 1 of this embodiment
Has two sample introduction systems, a hydride generator 2 and an ultrasonic nebulizer 3.

The hydride generator 2 has the same configuration as that of the conventional example shown in FIG.
A joint 5 into which a hydrogenating agent such as NaBH ₄ and a carrier gas such as Ar are introduced, a coil-shaped reaction tube 6 extending from the joint 5, and a communication tube 7 connected to the reaction tube 6. And a gas-liquid separation chamber 8 connected through the air-liquid separation chamber 8.

The gas-liquid separation chamber 8 separates the hydride M generated in the reaction tube 6 from the reaction residue L and stabilizes the analysis sensitivity. One end of a S-shaped pipe 9 for level adjustment and one end of a quick discharge pipe 10 for discharging a reaction residual liquid at the time of exchanging a sample liquid are connected to each other, and the other ends of the S-shaped pipe 9 and the quick discharge pipe 10 are both connected. Open to the drain tank 11. A peristaltic pump 12 for forcibly discharging the reaction residual liquid L is provided in the middle of the rapid discharge pipe 10.

On the other hand, the ultrasonic nebulizer 3 comprises a nebulizer main body 13 for atomizing a liquid sample by ultrasonic vibration, and a desolvating section 14, as in the conventional example.

The nebulizer body 13 is provided with an ultrasonic oscillator 16 in a spray chamber 15, and the surface of the ultrasonic oscillator 16 is driven by a pump 19 from a sample container 18 to supply hydride through a supply pipe 20. The same liquid sample S as the sample sent to the vessel 2 is sent and atomized by the vibration of the ultrasonic vibrator 16. The desolvation section 14 includes a heating stage 14a in the preceding stage.
In the heating stage 14a, the sample aerosol is heated and dried to form fine particles, and in the cooling stage 14b, the vaporized solvent is condensed by cooling and removed from the sample aerosol.

In the ICP emission spectrometer 1 of this embodiment, the hydride and the carrier gas from the gas-liquid separation chamber 8 of the hydride generator 2 are supplied to the spray chamber 15 of the nebulizer body 13.
Is supplied as a carrier gas through a carrier gas inlet pipe 17, whereby the atomized sample, hydride and carrier gas from the nebulizer main body 13 are supplied to the plasma torch 30 having a triple tube structure via the desolvation unit 14. It is being introduced. The plasma torch 30 is arranged coaxially with the high-frequency coil 22, and the atomized sample and the hydride from the ultrasonic nebulizer 3 are introduced together with the coolant gas and the plasma gas.

In the ICP emission spectrometer 1 having the above structure, when the liquid sample S, the hydrogenating agent, and the carrier gas are introduced together into the joint 5 of the hydride generator 2, Most of the liquid sample S and the hydrogenating agent react with each other to generate hydrides, and a part of the unreacted hydrogenating agent and the liquid sample S are directly transferred to the gas-liquid separation chamber 8.
Introduced within. In the gas-liquid separation chamber 8, the liquid sample S of the unreacted liquid and the hydrogenating agent completely react with each other to generate a hydride, and this hydride is transferred to the ultrasonic nebulizer 3 together with the carrier gas toward the ultrasonic nebulizer 3. Is sent as

On the other hand, in the ultrasonic nebulizer 3, the liquid sample S sent from the sample container 18 is sprayed on the ultrasonic vibrator 16 in the spray chamber 15 to be atomized, and the atomized sample is supplied to the hydride generator 2. The hydride and the carrier gas from the gas-liquid separation chamber 8 are combined, and the heating stage 1
It is heated and dried in 4a, and further cooled in the cooling stage 14b to remove the solvent and sent out to the plasma torch 30.

Thus, the hydride from the hydride generator 2 and the sample aerosol from the ultrasonic nebulizer 3 are mixed and introduced into the sample introduction tube of the plasma torch 30 at the same time, and are excited and emitted for analysis. .

As described above, the hydride from the hydride generator 2 and the sample aerosol from the ultrasonic nebulizer 3 are simultaneously introduced into the plasma torch 30 and analyzed.
As, where sensitivity is insufficient in a sample introduction system using a nebulizer,
Simultaneous analysis of elements such as Se, Sb, Bi and elements such as Cd, Fe, Zn, and Cr that cannot be converted to gaseous hydrides is possible. As in the conventional example, analysis is performed twice by replacing the sample introduction system. There is no need for this, and the analysis efficiency can be improved and the analysis cost can be reduced.

In addition, for the two sample introduction systems of the hydride generator 2 and the ultrasonic nebulizer 3, the carrier gas is only one system introduced into the hydride generator 2, so that the hydride generator 2 A pressure difference is hardly generated between the hydride and the ultrasonic nebulizer 3, and the hydride and the atomized sample are uniformly mixed.

As described above, simultaneous analysis of elements such as As, Se, Sb, and Bi and elements such as Cd, Fe, Zn, and Cr becomes possible. Suitable for test method of tap water.

Further, Y used as an internal standard substance,
Since Co, Sr, and the like are not reduced to gaseous hydrides, the internal standard analysis could not be performed in the conventional analysis using the hydride generator 2. However, in the present invention, the internal standard substance was converted by a nebulizer. It can be introduced at the same time, and internal standard analysis becomes possible.

[0027] FIG. 2 is a block diagram showing the overall ICP emission spectrophotometer 1 ₁ of another embodiment of the present invention, the parts corresponding to the embodiments described above, the same reference numerals.

In this embodiment, a nebulizer 25 of a spray type is provided in place of the ultrasonic nebulizer 3 of the above-described embodiment. The ICP emission spectrometer ₁₁ comprises a hydride generator 2 and a spray nozzle. System nebulizer 25-2
It has two sample introduction systems.

The nebulizer 25 of the spray type comprises a nebulizer main body 26 for atomizing the liquid sample S by jetting a carrier gas, and a spray chamber 27 for homogenizing the sample aerosol obtained by atomization by the nebulizer main body 26. Consists of

In this embodiment, the hydride and the carrier gas from the gas-liquid separation chamber 8 of the hydride generator 2 are supplied to the nebulizer 25 as a carrier gas, and the nebulizer 25 ejects the carrier gas. The liquid sample S is atomized, and the atomized sample and hydride are mixed and introduced into the plasma torch 30 together with the carrier gas.

Other configurations are the same as those of the above-described embodiment.

Also in this embodiment, the hydride generator 2
Is mixed with the sample aerosol of the nebulizer 25 of the spray type by the nebulizer 25, and is simultaneously introduced into the plasma torch 30 to be excited and emitted and analyzed.

[0033]

As described above, according to the present invention, the hydride and the carrier gas from the hydride generator are supplied as the carrier gas to the nebulizer for atomizing the liquid sample. And hydride are mixed and introduced into the plasma torch, and the sensitivity of the sample introduction system using the nebulizer is insufficient for As, Se, and As.
Elements such as Sb and Bi and elements such as Cd, Fe, Zn, and Cr that cannot be converted to gaseous hydride can be analyzed at the same time. Therefore, it is necessary to perform analysis twice by replacing the sample introduction system as in the conventional example. Therefore, the analysis efficiency can be improved and the analysis cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ICP emission spectrometer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an ICP emission spectrometer according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional example including a nebulizer of a spray type.

FIG. 4 is a configuration diagram of a conventional example including an ultrasonic nebulizer.

FIG. 5 is a configuration diagram of a conventional example including a hydride generator.

[Explanation of symbols]

1, 1 ₁ ICP emission spectrometer 2 hydride generator 3 ultrasonic nebulizer 25 nebulizer of spray type 30 plasma torch

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 21/62-21/74 G01N 1/28 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A hydride generator for reducing an element in a liquid sample to convert it into a hydride, and a nebulizer for atomizing the liquid sample, wherein the hydride and the carrier gas from the hydride generator are: An ICP emission spectrometer characterized by being supplied as a carrier gas to the nebulizer and introducing a hydride and an atomized sample from the nebulizer into a plasma torch.