JPH02198358A - Specimen analyzing method by heating - Google Patents

Abstract

PURPOSE:To extract all components to be analyzed in an enclosure which are extracted at a specified temperature by observing the extraction curve of a specimen, and performing holding. CONSTITUTION:A specimen such as metal is contained in a graphite crucible 1. An upper electrode 2 and a lower electrode 3 hold the crucible 1. The specimen is heated by current conduction. One end of an AC power source 4 is connected to the electrode 2 through an ammeter 5. The other end is connected to the electrode 3. A voltage across the electrodes 2 and 3 is measured with a voltmeter 6. When a current is made to flow through the crucible 1 by way of the electrodes 2 and 3, the crucible 1 generates Joule's heat which is determined by the magnitude of the resistance of the crucible and the magnitude of the current. The temperature of the crucible 1 is increased by said Joule's heat. As shown in the figure A, a small peak (c), which is difficult to separate in an automatic holding method as shown in the figure B, can be completely separated by manual holding shown by MH1 and MH2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for analyzing elements contained in a sample by applying electricity to a crucible containing the sample to heat it and analyzing the extracted gas. This invention relates to a sample analysis method using heated heating.

[Conventional technology]

The sample analysis method using heating described above can be used to analyze, for example, the amount of oxygen or nitrogen contained in a sample. ! This type of analysis is used to investigate K (or content rate), but the gas extracted by heating the sample exhibits unique extraction characteristics (also called extraction curves) depending on the type of gas. When doing this, hold the heating power and temperature while watching the extraction curve (
It is important to do this (hereinafter simply referred to as "hold").

In other words, as shown in Figure 3 (A), when the sample is heated without being held, the extraction output at that time becomes as shown in Figure 3 (B), and due to the difference in inclusions inside the sample, It is not possible to completely separate the peaks that are considered to occur (portions a and b in FIG. 3(B)).

On the other hand, when the microcomputer built into the sample analyzer automatically holds and heats the sample as shown in Figure 4 (A), the extraction output at that time is
As shown in the same figure (B), two peaks a and b are obtained in a completely separated state.

In FIG. 3(A) and FIG. 4(A), the horizontal axis shows time and the vertical axis shows power for heating, respectively. Also, in FIG. 3(A), HON indicates hold start, H
OFF indicates the end of the hold, and this figure shows that the hold was held twice at an appropriate interval.

[Problem to be solved by the invention]

However, it is only possible to successfully perform a predetermined peak separation by automatically holding the microcomputer as described above when it is known in advance at which time axis the extracted gas generated from the sample will appear. When analyzing an unknown sample such as a new material, or when a known sample has a shape, amount, etc. that is different from the conventional one, it is difficult to perform the above-mentioned peak separation successfully.

When holding is automatically performed using a microcomputer, judgments are made based on a predetermined program while processing the extracted gas signal, but the timing of hold on and off is not perfect, and peaks may be overlooked. When there are multiple targets to be analyzed (for example, oxygen and nitrogen), it is difficult to flexibly decide which of them to hold.

Furthermore, when automatically holding as described above, the processing is uniformly performed inside the device, that is, by the microcomputer, which may result in the control not being performed as intended by the person conducting research or development.

That is, as shown in FIG. 5(A), when the sample is heated without holding, the extraction output appears as shown in FIG. 5(B). In this case, if you want to separate and extract part C between peaks a and b,
Even if it is automatically held by a microcomputer and heated as shown in FIG. 6(A), the portion C may not be completely separated as shown in FIG. 6(B).

The present invention has been made with the above-mentioned considerations in mind, and its purpose is to compensate for the shortcomings of the conventional automatic hold method, and to utilize a heating method that allows researchers and other operators to perform control as intended. The object of the present invention is to provide a sample analysis method.

[Means to solve the problem]

In order to achieve the above-mentioned object, the sample analysis method by heating according to the present invention manually controls the power or temperature based on the extraction peak of the component to be analyzed during power-raising or temperature-raising analysis. The feature is that it is made to hold.

[Effect]

According to the above configuration, since it can be held arbitrarily in accordance with the extraction curve extracted from the sample, even small peaks can be reliably separated, and the above objective is completely achieved.

〔Example〕

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

FIG. 1 schematically shows the configuration of the main parts of a sample analysis apparatus to which the method of the present invention is applied. In this figure, l is a crucible such as a graphite crucible, and a sample of metal or the like is housed inside the crucible. Reference numerals 2.3 denote an upper electrode and a lower electrode for holding the crucible 1 and heating it by applying electricity to it. 4 is an AC power supply,
One end thereof is connected to the upper electrode 2 via an ammeter 5, and the other end is connected to the lower electrode 3. 6 is the picture electrode 2
This is a voltmeter for measuring voltage between ゜3.

In the above configuration, when a current is passed through the crucible 1 through the picture electrode 2.3, the crucible 1 generates Joule heat determined by the magnitude of its resistance and the magnitude of the current, and this Joule heat causes the temperature of the crucible 1 to rise. will rise.

In the present invention, the power or temperature is held based on the extraction peak of the component to be analyzed in order to hold the currently applied power constant at any timing according to a preset sample heating pattern. That's what I do.

That is, in FIG. 2(A), MH,, MH.

By manually holding it as shown in the figure (
As shown in B), it is now possible to completely separate the small peak C, which was difficult to separate using the conventional automatic hold method.

In FIG. 2(B), MHON indicates the start of manual hold, and MHOFF indicates the end of manual hold.

〔Effect of the invention〕

As explained above, according to the present invention, by holding the sample while watching the extraction curve, all analytical components (e.g. oxygen and nitrogen) in the inclusions extracted at that temperature can be extracted. This can prevent the extraction peaks of other inclusions from overlapping. Since the hold can be turned on and off only manually, the device can be operated as intended by the researcher.

In addition, in the past, unknown samples were given a continuous electric power or temperature rise to uniquely determine the generated gas situation, but according to the method of the present invention, the electric power can be applied arbitrarily depending on the characteristics of the sample, etc. Or, it became possible to maintain the temperature.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention, Figure 1 is a schematic diagram of the main parts of sample analysis to which the method of the present invention is applied, and Figure 2 (A) is the applied power. FIG. 2(B) is a diagram showing the extraction curve. Figures 3 to 6 are diagrams for explaining the prior art.
Figure (A), Figure 4 (A), Figure 5 (A) and Figure 6 (
A) is a diagram showing the changes in applied power, Figure 3 (Japanese), Figure 4 (B), Figure 5 (B), and Figure 6 (F).
3) is a diagram showing each extraction curve. 1... Crucible.

Claims (1)

[Claims] In a sample analysis method using heating, in which the elements contained in the sample are analyzed by applying electricity to a crucible containing the sample to heat it and analyzing the extracted gas, the analysis target is 1. A method for analyzing a sample by heating, characterized in that the power or temperature is manually controlled based on the extraction peak of a component and the power or temperature is held.