JPH05180770A - Icp emission spectrophotometer - Google Patents

Abstract

PURPOSE:To eliminate the change of the particle density of an aerosol and to obtain a stable measuring signal from a plasma torch by providing a buffer chamber whose inner diameter is larger than that of an aerosol feed pipe on the midway part of the sample aerosol feed pipe reaching the plasma torch from a nebulizer part. CONSTITUTION:The feed pipe 9 feeding the sample aerosol S from a nebulizer part 1 to a plasma torch 2 is divided on the midway part thereof and a buffer chamber 10 is provided to the divided part. The chamber 10 has an inner diameter larger than that of the feed pipe 9. An inflow port 10a is opened at the upper end of the chamber 10 and one divided end of the pipe 9 is connected to the inflow port 10a. The outflow pipe 10b connected to the other divided end of the pipe 9 protrudes into the chamber 10 and a spherical suction part 11 having a large number of through-holes provided on the peripheral surface thereof is fitted to the outflow pipe 10b. By this constitution, the sample aerosol S generates a stirring stream by its inflow velocity in the chamber 10 to be mixed and the particle density thereof is equalized and emission intensity is not changed by density change to become stable.

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 spectroscopic analyzer, and more particularly to the structure of a sample aerosol carrying path from a nebulizer section to a plasma torch.

[0002]

2. Description of the Related Art In an ICP emission spectroscopic analyzer, a liquid sample is aerosolized by a nebulizer and introduced into a plasma torch together with a carrier gas.

FIG. 2 shows a schematic structure of a main part of a conventional ICP emission spectral analyzer. In the figure, reference numeral 1 is a nebulizer portion, and 2 is a plasma torch. Nebulizer part 1
Is a nebulizer body 3 that atomizes a liquid sample by ultrasonic waves.
And a desolvation unit 4. In the nebulizer main body 3, the liquid sample S sent from the sample container 5 by the pump 6
Is sprayed on the ultrasonic transducer 8 in the atomization chamber 7 and atomized. The desolvation section 4 is composed of a heating stage 4a in the front stage and a cooling stage 4b in the rear stage. In the heating stage 4a, the nebulizer body 3 is
The sample aerosol from (3) is heated and dried into fine particles, and in the cooling stage 4b, the vaporized solvent is condensed by the cooling and removed from the sample aerosol. Reference numeral 9 is a carrier pipe for carrying the sample aerosol from the nebulizer unit 1 to the plasma torch 2.

By the way, in the conventional apparatus, the carrier pipe 9 connected to the plasma torch 2 and the pipe passing through the desolvation section 4 are
The sample aerosol from the nebulizer body 4 is composed of tubes having substantially the same inner diameter so that the sample aerosol flows in a laminar flow state. This is because, if there is a step due to a difference in inner diameter in the middle of the transfer tube 9 or the desolvation section 4, the sample aerosol will stay at that point and the aerosol particles will adhere to the tube wall.

[0005]

However, in the structure in which the sample aerosol is conveyed through the tube having the constant inner diameter as described above, when the density of the particle of the sample aerosol fluctuates in the nebulizer main body 3, the fluctuation of the density fluctuates. Since it is sent to the plasma torch 2 in the form of a compressional wave, the density of the particle density appears as a change in the intensity of the photometric signal as it is, and a stable photometric signal cannot be obtained, which adversely affects measurement accuracy.

The present invention has been made in view of the above problems, and stabilizes a photometric signal by introducing a sample aerosol into a plasma torch in a state in which the density of particles does not vary in density. Is an issue.

[0007]

In order to achieve the above-mentioned object, the present invention provides an ICP emission spectroscopic analysis apparatus, which is provided in a midway part of a sample aerosol carrying pipe from a nebulizer part to a plasma torch rather than the carrying pipe. A buffer chamber having a large inner diameter is provided.

[0008]

According to the above-mentioned structure, the sample aerosol supplied from the nebulizer portion flows into the buffer chamber before the plasma torch and is mixed, and is introduced into the plasma torch in a state where the particle density is equalized. ..

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a schematic structure of a main part of an ICP emission spectral analyzer according to an embodiment of the present invention.

As shown in FIG. 1, the ICP emission spectroscopic analyzer of this embodiment comprises a nebulizer section 1 and a plasma torch 2, and the nebulizer section 1 nebulizer body 3 atomizes a liquid sample by ultrasonic waves. And the desolvation unit 4 are the same as in the conventional example described above. Further, the nebulizer body 3 sprays the liquid sample S sent from the sample container 5 by the pump 6 onto the ultrasonic vibrator 8 in the atomization chamber 7, and atomizes the liquid sample S. Similar to the conventional example, the sample aerosol from the nebulizer body 3 is composed of a former heating stage 4a for finely pulverizing the sample aerosol by heating and drying, and a latter cooling stage 4b for removing the vaporized solvent by dew condensation by cooling. is there.

The difference of the ICP emission spectroscopic analyzer of this embodiment from the conventional example is that the carrier pipe 9 for carrying the sample aerosol from the nebulizer unit 2 to the plasma torch 1 is divided at an intermediate portion, and between the divided portions, That is, the buffer chamber 10 is connected for communication. This buffer chamber 10
Is for equalizing the particle density of the sample aerosol by mixing, and has an inner diameter larger than the inner diameter of the carrier tube 9. In the illustrated example, an inflow port 10a is opened at the upper end of the buffer chamber 10, and one divided end of the carrier pipe 9 is connected to the inflow port 10a. Further, the outflow pipe 10b connected to the other divided end of the transfer pipe 9 projects into the buffer chamber 10, and a spherical suction portion 11 having a large number of through holes on its peripheral surface is provided at the projecting end. ing.

In the above structure, the sample aerosol generated in the nebulizer body 3 is made into fine particles and the solvent is removed in the desolvation section 4, and is sent to the plasma torch 1 side through the carrier pipe 9. It flows into the buffer chamber 10 at some midpoint of the transfer pipe 9. In this buffer chamber 10, the sample aerosol produces a stirred flow due to its own inflow velocity and is mixed to equalize its particle density.

In this case, the sample aerosol stays in the buffer chamber 10, but the sample aerosol from the nebulizer section 1 is sufficiently finely divided by the desolvation section 4 so that it may adhere to the inner wall of the buffer chamber 10. There is almost nothing.

Then, the sample aerosol in which the particle density is equalized is passed through the downstream transfer pipe 9 to the plasma torch 2.
By flowing into the plasma torch 2, the variation of the emission intensity due to the density of the particle density is eliminated, and the emission intensity is stabilized. Therefore, a stable photometric signal can be obtained.

In the illustrated example, the nebulizer main body 3 is of the type that atomizes by ultrasonic waves, but the present invention is also applicable to an apparatus having a nebulizer that atomizes a sample by jetting a carrier gas. Of course, it can be applied.

[0016]

According to the present invention, even if the sample aerosol from the nebulizer section has a variation in the density of the particle density, the density of the sample aerosol is equalized by the mixing in the buffer chamber, so that the plasma torch is As a result, a sample aerosol that does not fluctuate in light and shade is supplied, and a stable photometric signal can be obtained from the plasma torch, improving the measurement accuracy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an ICP emission spectroscopy analyzer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a main part of a conventional ICP emission spectroscopy analyzer.

[Explanation of symbols]

 1 Nebulizer part 2 Plasma torch 3 Nebulizer body 4 Desolvation part 9 Transfer pipe 10 Buffer chamber

Claims (1)

[Claims] 1. An ICP emission spectroscopic analyzer characterized in that a buffer chamber having an inner diameter larger than that of the carrier pipe is provided in the middle of the sample aerosol carrier pipe from the nebulizer part to the plasma torch.