JPH1144644A - Icp analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ICP(high-frequency inductively coupled plasma) analyzer capable of increasing an analysis precision suppressing pressure fluctuation in a spray chamber, even if a waste liquid is discharged in a lump. SOLUTION: A sample 7 is nebulized by a nebulizer 6 and sprayed into a spray chamber 1, and the nebulized sample is led to a plasma torch 8. As a matter of fact, only mist having fine grain diameters is led to the plasma torch 8. A great part of it such as large fog drops adheres the internal wall of the spray chamber 1, sinks by the own weight, and becomes a solution to collect at a drain outlet provided at the bottom of the spray chamber 1. A waster liquid is caused to flow out of a U-tube 4 by the increase of this new waste liquid by its amount, but the fluctuation of the liquid level of the spray chamber 1 is suppressed, and pressure fluctuation is reduced, since a buffer container 3 is provided between the U-tube 4 and the spray chamber 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ICP (High Frequency Inductively Coupled Plasma) emission spectrometer and an ICP analyzer used as an ICP-mass spectrometer (MS).

[0002]

2. Description of the Related Art ICP (High Frequency Inductively Coupled Plasma;
CP) is an excellent excitation light source for elemental analysis.
It is often used as an ion source.
As shown in FIG. That is, most of the sample is treated with a liquid. However, the sample 7 is atomized by the nebulizer 6 in the spray chamber 1 and is guided to the plasma torch 8 as an aerosol, and a high-frequency magnetic field generated by the high-frequency coil 9 is used. To generate plasma, and measure the emission intensity and the amount of ions to perform qualitative and quantitative analysis of the elements in the sample.

In such an ICP analysis, of the sample 7 atomized in the spray chamber 1, the aerosol introduced into the plasma torch 8 is only a small part, and most of the aerosol is again mixed with the solution in the spray chamber 1. Is discharged. This discharge is performed by connecting the waste liquid reservoir 2 to the drain of the spray chamber 1, connecting the U-shaped tube 4 to the other end of the waste liquid reservoir 2, and discharging to the drain tank 5 via the U-shaped tube 4. Has become. Since the U-shaped pipe 4 is installed at a predetermined height, the waste liquid is stored in the waste liquid storage pipe 2,
Even if the surplus liquid is discharged from the U-shaped tube 4, the waste liquid level of the spray chamber 1 can be kept constant, whereby the pressure in the spray chamber 1 is designed to be constant. Further, there is also a function of preventing the argon gas used for introducing the sample aerosol from passing through the discharge port by storing the waste liquid in the waste liquid storage tube 2.

[0004]

Although the conventional ICP analyzer is constructed as described above, it is necessary to stabilize the plasma in order to perform the ICP analysis with high accuracy. It is important to keep constant. Although there is no single factor that causes the pressure in the spray chamber 1 to fluctuate, the treatment of the waste liquid in the spray chamber 1 described above also poses a problem. That is, in FIG. 2, the materials of the spray chamber 1, the waste liquid storage tube 2, and the U-shaped tube 4 are made of a chemical resistant material such as glass or Teflon in consideration of the fact that the sample to be handled is an organic solvent or chemicals. Used and generally poor in hydrophilicity. Therefore, the waste liquid is not gradually discharged from the U-shaped tube 4, and when the storage amount in the waste liquid storage tube 2 exceeds a certain value, the waste liquid is suddenly lost as a lump. In this case, there is a problem that the liquid level in the spray chamber 1 fluctuates, the pressure fluctuates, and the plasma becomes unstable.

The present invention has been made in view of such circumstances, and in the ICP analysis, the liquid level in the spray chamber 1 is kept stable at the time of analysis, so that accurate analysis can always be performed. It is intended to provide a sample introduction device for ICP analysis.

[0006]

In order to achieve the above object, an ICP analyzer according to the present invention comprises a spray chamber 1 constituting a sample introduction device and a level of a liquid stored in the spray chamber 1 kept constant. U-shaped tube 4 provided to keep
And a buffer container 3 whose upper part is hermetically closed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ICP analyzer of the present invention will be described with reference to FIG. In the figure, 1 is a spray chamber, 2 is a waste liquid reservoir, 3 is a buffer container, 4 is a U-shaped tube, 5 is a drain tank, 6 is a nebulizer, 7 is a sample, 8 is a plasma torch, and 9 is a high frequency coil. .

[0008] The upper part of the buffer container 3 is sealed,
A connection port for the waste liquid storage pipe 2 is provided at a lower portion, and a connection port for the U-shaped pipe 4 is provided at an intermediate position of the height of the buffer container 3. The other end of the waste liquid storage pipe 2 connected to the lower part is connected to the drain port of the spray chamber 1, and the connection port to the U-shaped pipe 4 in the middle of the buffer vessel 3 is provided with an elbow type pipe. The U-shaped tube 4 is connected. The other end of the U-shaped tube 4 is connected to the drain tank 5, and the waste liquid is finally stored here. The upper part of the U-shaped tube 4 has an air vent opening.

Prior to the analysis, a solvent is stored in the waste liquid storage tube 2 and the buffer container 3 in advance. The relative positions of the heights of the spray chamber 1, the buffer container 3 and the U-shaped tube 4 are set as shown in FIG. When argon gas is being supplied from the nebulizer 6, the liquid level is at A in the spray chamber 1, B at the buffer vessel 3 and C at the U-tube 4. Here, since the U-tube 4 is released to the atmospheric pressure, a pressure corresponding to the water column height of the liquid surface height C of the U-tube 4 is applied to the liquid level B of the buffer container 3. become.

At the time of analysis, the sample 7 is atomized by the nebulizer 6 and sprayed into the spray chamber 1. The atomized sample is guided to the plasma torch 8 after the spray chamber 1 achieves uniform particles and stabilizes the air flow. Actually, only a mist with a fine particle diameter is introduced into the plasma torch 8, and most of large mist droplets adhere to the inner wall of the spray chamber 1 and settle down by their own weight to form a solution, and a drain at the bottom of the spray chamber 1 is formed. Collect in your mouth.

[0011] Due to the increase of this new waste liquid, U
The waste liquid flows out from the U-shaped pipe 4, but the waste liquid is not gradually discharged because the U-shaped pipe 4 has poor hydrophilicity, and becomes a lump when the amount of waste liquid exceeds a certain value. I'm flowing at a stretch. According to the conventional method, this immediately causes the liquid level of the spray chamber 1 to vibrate up and down to fluctuate the pressure in the spray chamber 1, but in the present invention, the buffer container 3 comprises the U-tube 4 and the spray chamber 1. Because the liquid level of the spray chamber 1 is not directly affected, the effect is also exerted on the liquid level of the buffer container 3. However, since the upper portion of the buffer container 3 is closed, this space functions as an air spring and functions to suppress the amplitude of the vertical vibration of the liquid surface. As a result, the liquid level in the spray chamber 1 can be suppressed from fluctuating up and down due to discharge of waste liquid from the U-shaped tube 4. The buffer container 3 only needs to have a closed upper surface, and may have any shape.

[0012]

According to the ICP analyzer of the present invention having the above-described structure, a buffer container whose upper part is hermetically sealed is provided between the spray chamber and the U-shaped tube, so that the upper space of the buffer container functions as an air spring. The pressure fluctuation in the spray chamber is reduced even if the waste liquid is discharged from the U-shaped pipe,
The stability of the plasma and thus the accuracy of the analysis is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of an ICP analyzer of the present invention.

FIG. 2 is a diagram showing a conventional ICP analyzer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Spray chamber 2 ... Waste liquid reservoir 3 ... Buffer container 4 ... U-shaped tube 5 ... Drain tank 6 ... Nebulizer 7 ... Sample 8 ... Plasma torch 9 ... High frequency coil

Claims (1)

[Claims] 1. An ICP analyzer for analyzing a sample atomized by a nebulizer by introducing a sample atomized by a nebulizer into a plasma torch via a spray chamber to excite and emit and ionize the sample, wherein the spray chamber and a liquid surface stored in the spray chamber An ICP analyzer characterized in that a buffer container serving as a waste liquid tank whose upper part is hermetically closed is provided between a U-shaped pipe provided for keeping the height of the wastewater constant.