JPH0650887A - Atomization furnace for atomic absorption analytical apparatus - Google Patents

Abstract

PURPOSE:To make the existence time inside a furnace of a vapor definite by a method wherein a detachable cover which closes and opens a sample injection port at the upper part of the circumferential wall of a tubular body whose cross section is circular is attached and an atomic-vapor discharge port is formed in a part facing the sample injection port in a closed position. CONSTITUTION:An atomization furnace 1 is composed of a graphite tubular furnace main body 2 whose cross section is wholly circular and of a graphite cover 4 which is attached to its outside so as to be detachable and whose cross section is semicircular. The cover 4 can be slid freely between the closed position and the open position of a sample injection port 3. An atomic-vapor discharge port 5 is formed in a position facing the injection port 3 in its closed position. A recessed part used to arrange the sample is formed in a part corresponding to the discharge port 5 at the lower part of the circumferential wall of the main body 2. In an absorption analysis, the cover 4 is opened, the sample is dropped from the injection port 3, and the sample is held in the recessed part. Then, the cover 4 is closed, the furnace 1 is arranged in an atomization part for an absorption analytical apparatus, an electric current is supplied, the furnace 1 is heated, and an absorption analysis is performed. By this structure, the existence time inside the furnace 1 of an atomic vapor becomes definite, and the analytical sensitivity of the analytical apparatus is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an atomization furnace used in an atomic absorption spectrometer for atomizing a solid or liquid sample by electric heating.

[0002]

2. Description of the Related Art Heretofore, as this type of atomization furnace, there has been used one in which a graphite tubular body having a circular cross section as a whole is formed, and a through hole for sample injection and atomic vapor discharge is formed in an upper portion of a peripheral wall thereof. It was In this atomization furnace, a solid or liquid sample is introduced into the furnace by dropping it into the furnace through a through hole.

[0003]

By the way, in the atomic absorption spectrometer, the sensitivity of the analysis is determined by the time during which the vapor generated from the sample remains in the atomization furnace before being discharged from the through hole. It is known that the atomic vapor discharge port may be made small in order to improve the analysis sensitivity.

However, in the conventional atomization furnace, the through hole formed in the peripheral wall serves both as the sample inlet and the atomic vapor discharge port. Therefore, if the through hole is made small in order to improve the analysis sensitivity, a large solid material is obtained. In the case of a sample, there is a problem that it cannot be put into the furnace, and conversely, there is a problem that the sensitivity decreases when the through hole is enlarged.

Further, in the case of a liquid sample, if the size of the atomic vapor discharge port is constant, the time during which the vapor generated from the sample remains in the reactor until being discharged from the through hole is constant. In order to achieve this, it is necessary to make the concentration of the sample to be charged into the atomization furnace constant, and there is a problem that the work is troublesome because the sample must be diluted or concentrated.

An object of the present invention is to provide an atomization furnace for an atomic absorption spectrometer which solves the above problems.

[0007]

The atomization furnace for an atomic absorption spectrometer according to the present invention comprises a tubular furnace body having a circular cross section and a sample charging port formed in an upper part of a peripheral wall, and a closed position for closing the sample charging port. And a cover detachably attached to the outside of the furnace main body so as to take an open position to open it, and an atomic vapor discharge port is formed in a portion of the cover facing the sample inlet at the closed position. It is a thing.

In the above, the furnace body and the cover are made of graphite. The inner peripheral surface of the furnace body and the inner surface of the cover may be subjected to pyrolysis treatment or metal carbide treatment. Also, as the cover, tantalum, molybdenum,
It may be formed of a refractory metal such as tungsten.

[0009]

[Function] Since the sample inlet is formed in the furnace body and the atomic vapor outlet is formed in the cover, the size of the sample inlet and the atomic vapor outlet should be set to the size suitable for the purpose. You can Therefore, the size of the atomic vapor discharge port can be reduced to increase the sensitivity of analysis, and the size of the sample input port can be increased to input a large solid sample.

Further, since the cover is detachably attached to the outside of the furnace body so as to have a closed position for closing the sample inlet and an open position for opening the sample inlet, the atomic vapor outlets of different sizes can be installed. Prepare multiple covers that you have,
By using a cover that has an atomic vapor outlet with a size corresponding to the concentration of the liquid sample, even if the concentration of the liquid sample is different, the vapor generated from the sample is It is possible to make the time that exists in the chemical conversion furnace constant.

[0011]

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

The atomization furnace (1) for an atomic absorption spectrometer according to the present invention has a circular cross section and a sample inlet at the upper part of the peripheral wall.
Graphite tubular furnace body (2) with (3) formed, and furnace body (2)
It consists of a graphite cover (4) with a semicircular cross section that is detachably attached to the outside of the. The curvature of the inner surface of the cover (4) is equal to the curvature of the outer peripheral surface of the furnace body (2). And
The cover (4) is slidable between a closed position (see the solid line in FIG. 1) that closes the sample inlet (3) and an open position (see the chain line in FIG. 1) that opens the cover. Atomic vapor discharge port (5) is formed in the closed position of cover (4) facing sample input port (3). The size of the sample inlet (3) is
Be large enough to pass the largest expected solid sample. The size of the atomic vapor discharge port (5) should be such that it can be analyzed with high sensitivity. When the cover (4) on the inner peripheral surface of the lower part of the peripheral wall of the reactor body (2) is in the closed position, the sample placement recess (6) is located at the portion corresponding to the atomic vapor discharge port (5).
Are formed.

In such an arrangement, when carrying out atomic absorption analysis using a solid sample (S), first slide the cover (4) to the open position, and then from the sample inlet (3) to the furnace body.
(2) Drop it inside. Then, the sample (S) enters the recess (6) and is held there. Then, after sliding the cover (4) to the closed position, place the atomization furnace (1) in the atomization section of the atomic absorption spectrometer and heat it by energizing the atomization furnace (1) to obtain a solid sample. (S) is vaporized. Then, atomic absorption analysis is performed.

In the above, a large solid sample (S) can be introduced from the sample inlet (3) even if the size of the atomic vapor outlet (5) is made small in order to increase the sensitivity of analysis. become.

A sample introduced into the atomization furnace (1)
Since the position of (S) with respect to the atomic vapor discharge port (5) is always constant, if this is vaporized, the atomic vapor will be in the reactor (1) by the time it is discharged from the atomic vapor discharge port (5). The time that is present is always constant, improving the sensitivity of the analysis.

When carrying out atomic absorption analysis using a liquid sample, a plurality of covers (4) having atomic vapor discharge ports (5) of different sizes are prepared in advance, and the size of the cover depends on the concentration of the liquid sample. By using the cover (4) with the atomic vapor outlet (5), even if the concentration of the liquid sample is different, the vapor generated from the sample will be atomized by the time it is emitted from the atomic vapor outlet (5). The time spent in the furnace (1) can be constant.

[0017]

As described above, according to the atomization furnace for an atomic absorption spectrometer of the present invention, a large solid sample can be obtained even if the size of the atomic vapor discharge port is made small in order to increase the sensitivity of the analysis. Can be charged from the sample charging port. Therefore, regardless of the size of the fixed sample, the analysis can always be performed with high sensitivity.

Further, by preparing a plurality of covers having atomic vapor discharge ports of different sizes and using a cover having atomic vapor discharge ports of a size corresponding to the concentration of the liquid sample, Even if the concentration is different, it is possible to make the time that the vapor generated from the sample stays in the nuclear reactor until it is discharged from the atomic vapor discharge port, so it is necessary to dilute or concentrate the liquid sample. Is unnecessary and workability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an atomization furnace for an atomic absorption spectrometer according to the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

[Explanation of symbols]

 1 Atomic absorption spectrometer atomic reactor 2 Furnace body 3 Sample inlet 4 Cover 5 Atomic vapor outlet

Claims (1)

[Claims] 1. A tubular furnace body having a circular cross section and having a sample introduction port formed in an upper portion of a peripheral wall, and a tubular furnace body outside the furnace body so as to have a closed position for closing the sample introduction port and an open position for opening the sample introduction port. An atomization furnace for an atomic absorption spectrometer, comprising a detachably attached cover, and an atomic vapor discharge port is formed at a portion of the cover facing the sample inlet at a closed position.