JPH0740027B2 - Elemental analysis method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for analyzing an element in a sample by using a graphite crucible.

[Prior Art] Conventionally, when performing elemental analysis using the graphite crucible, a graphite crucible is inserted between upper and lower electrodes inside an elemental analyzer, and the graphite crucible is sandwiched between the upper and lower electrodes, and a metal Samples such as the above are supplied to a sample feeder, and in a state where the elemental analyzer is placed under a gas seal, the graphite crucible is electrically heated for degassing, and the sample is placed in the graphite crucible. Then, the sample is melted and the elements in the sample are analyzed based on the generated gas.

Then, when the above elemental analysis is completed, the used graphite crucible is taken out, and thereafter, the above-described means is repeated to perform elemental analysis on a plurality of samples.

[Problems to be Solved by the Invention]

However, since the graphite crucible is replaced every time elemental analysis is performed, the running cost is high, and since the graphite crucible is replaced and the sample is supplied to the sample feeder each time, elemental analysis of multiple samples is required. It took a lot of time.

When the elemental analysis target is ceramics, etc.,
Flux was added to the graphite crucible, and although the flux used for the analysis may still be functionally effective, it was discarded together with the graphite crucible, which was very wasteful.

The present invention has been devised in view of the above circumstances, and an object thereof is to provide an elemental analysis method that achieves a reduction in running cost and a reduction in analysis time.

[Means for Solving the Problems]

In order to achieve the above object, the elemental analysis method of the present invention has an upper electrode and a lower electrode that sandwich a graphite crucible from above and below, and a plurality of sample feeders for the graphite crucible are arranged in parallel vertically. In addition, while supplying each sample to the hopper provided in each sample feeder, using an elemental analyzer having a lid that opens and closes the sample supply hole to each hopper, electrically heat the graphite crucible. A method of melting a sample supplied to the graphite crucible and analyzing an element in the sample, wherein the lid is opened, and the graphite crucible is placed on the electrode surface of the lower electrode, and hand,
After supplying a sample to each of the plurality of sample feeders through each sample supply hole, degassing the graphite crucible while the lid is closed and the elemental analyzer is placed under a gas seal. , The lowest sample is slid to position the sample being supplied directly above the sample charging hole communicating with the graphite crucible, and the sample is charged into the graphite crucible for elemental analysis. It is characterized in that the samples supplied to the second and subsequent hoppers are sequentially charged for elemental analysis, and that the above-mentioned graphite crucible is repeatedly used for elemental analysis of each sample.

[Action]

It has an upper electrode and a lower electrode that sandwich the graphite crucible from above and below, and a plurality of sample feeders for the graphite crucible are arranged side by side vertically, and each sample is supplied to a hopper equipped in each sample feeder. In addition, since an elemental analyzer having a lid that opens and closes the sample supply hole to each of the hoppers was used, it is possible to supply the samples at once to a plurality of sample feeders and repeatedly use the graphite crucible. Thus, elemental analysis of a plurality of samples can be continuously performed.

Then, by supplying the flux to one of the hoppers provided in each sample feeder, the elemental analysis according to the present invention can be performed using the flux, and the flux can be reused as necessary. The elemental analysis of a plurality of samples can be continuously performed.

〔Example〕

First, an example of an elemental analysis device necessary for carrying out the method of the present invention will be described with reference to FIG.

In the figure, reference numeral 1 is a mounting member to the base 2, and a tubular member 3 is provided on the free end side. Reference numeral 4 denotes an upper electrode that is hung continuously on the free end side of the mounting member 1, and forms a sample inlet 5 that communicates with the tubular member 3 and a graphite crucible storage space P that communicates with the sample inlet 5. And the sample inlet 5
The lower surface of the peripheral portion is formed on the electrode surface 6. Reference numeral 7 denotes a lower electrode which can freely move in and out of the space P, and its upper surface is formed as an electrode surface 8. Reference numeral 9 is a graphite crucible sandwiched between the electrode surfaces 6 and 8 of the upper and lower electrodes 4 and 7, and is electrically heated by energizing the electrodes 4 and 7.

Reference numeral 10 denotes a first sample feeder installed on the free end side of the mounting member 1 and is configured as follows.

That is, a lower hole a communicating with the cylindrical member 3, an upper hole b concentric with the lower hole a, and a sample passage hole c are formed in the first cylinder 11 and the inside of the first cylinder 11 is formed. A second cylindrical body 12 is slidably provided on the upper and lower portions of the second cylindrical body 12, and the upper hole b and the sample passage hole c are communicated with each other as the slide moves. While forming the sample dropping holes d and e,
Further, inside the second cylindrical body 12, the upper and lower sample charging holes are provided.
A first hopper 13 for sample storage is provided for switching d and e between a communication state and a closed state.

The sample storage hopper 13 is composed of a fixed member 13a fixedly provided inside the second cylindrical body 12 and a movable member 13b which can be brought into contact with and separated from the fixed member 13a, and both the members 13a and 13b. Hopper surface portions are formed on the upper portions of the corresponding surface portions, and the second cylindrical body 12 and the movable member 13b are respectively connected to the first and second driving means 14 and 15 for slide operation. It is set up.

Next, 16 in the drawing is a second sample throwing machine, which is installed on the upper part of the first sample throwing machine 10 and is configured as follows.

That is, the third tubular body 17 is provided on the upper portion of the first tubular body 11, and upper and lower holes f and g which are concentric with each other and communicate with the upper hole b of the first tubular body 11, and the first tubular body 11. A sample supply hole h communicating with the sample passage hole c of the body 11 is formed in the third cylindrical body 17, and a hopper surface portion is formed above the relative surface portion. One is a fixed member 18a and the other is a movable member 18b. The second sample storage hopper 18 which is a third drive means 19 for incorporating the second sample storage hopper 18 into the third cylindrical body 17 and slidingly operating the movable member 18b.
And a lid 20 for opening and closing the sample supply hole h and the upper hole f, and a monitor window 21 for monitoring the inside of the graphite crucible. It is provided.

Gas seal packing is provided between the contact surfaces of the various components.

Next, a procedure of elemental analysis of a sample performed using the elemental analysis device having the above-described configuration will be described.

First, as shown in FIG. 2A, the lid 20 is opened, and the graphite crucible 9 is placed on the electrode surface 8 of the lower electrode 7.

Next, as shown in FIG. 2 (B), the lower electrode 7 is projected into the space P of the upper electrode 4 to sandwich the graphite crucible 9 between the lower electrode 7 and the upper electrode 4, and First
And the samples n ₁ and n in the hoppers 13 and 18 of the second sample feeders 10 and 16, respectively.
Supply ₂ .

Next, as shown in FIG. 2 (C), the lid 20 is closed, the elemental analysis apparatus is placed under a gas seal, the inside of the apparatus is purged with an inert gas, and the upper and lower electrodes 4, 7 are attached. An electric current is passed to electrically heat the graphite crucible 9 to degas the graphite crucible 9 and measure the blank value of the graphite crucible 9.

Next, as shown in FIG. 2 (D), the second cylinder 12 of the first sample inserter 10 is slid so that the sample dropping hole e of the second cylinder 12 is made into the pilot hole a of the first cylinder 11. 2E, the movable member 13b of the first hopper 13 is moved away from the first hopper 13, and the first sample n ₁ is charged into the graphite crucible 9.

Here, the first sample n ₁ is heated and melted in the graphite crucible 9 to melt and extract the elements in the sample, and the extracted gas is sent as a carrier gas to a gas analyzer (not shown) to make the first sample n ₁ A predetermined gas analysis for

Next, if necessary, the graphite crucible 9 is degassed again, and then the movable member 18b of the second sample feeder 16 is moved away from the first crucible as shown in FIG. 1 sample n ₁
The second sample n ₂ was placed in a graphite crucible 9 used in the analysis, the second sample n ₂ extracts melting element in the sample by heating and melting in the graphite crucible 9, the carrier and the extraction gas The gas is sent to a gas analyzer (not shown) to perform a predetermined gas analysis on the second sample n ₂ .

This completes the elemental analysis of one surface of the two samples. Thus, the above-mentioned elemental analysis can be performed continuously using the same graphite crucible 9 whose blank value is known, By repeatedly using the crucible 9, the running cost is reduced, and the replacement of the graphite crucible and the supply of the sample to the sample introduction machine are halved, so that the labor and time required for the operation can be shortened.

In consideration of the number of reusable times until the graphite crucible 9 is damaged, the elemental analysis is repeated by reusing the graphite crucible 9 itself until the graphite crucible 9 is damaged. Further reduction of
It is possible to further reduce the time and labor for replacing the graphite crucible.

If the graphite crucible 9 such as iron or nickel that corrodes the graphite crucible 9 as the sample to be analyzed, the graphite crucible 9
However, if the graphite crucible 9 does not corrode or is difficult to corrode into copper, tin, or ceramics, the graphite crucible 9 has a high durability and can be reused for a total of about 10 analyzes. Endure.

By the way, in the above-mentioned embodiment, the element analyzer is equipped with the two sample introduction machines 10 and 16, but by equipping three or more sample introduction machines, the element analysis can be performed in a shorter time. Needless to say, or by supplying the flux to one of the hoppers provided in each sample feeder, it is possible to perform elemental analysis using the flux as necessary,
If the used flux is still functionally effective, it can be reused for elemental analysis.

〔The invention's effect〕

As described above, according to the present invention, the graphite crucible has an upper electrode and a lower electrode that sandwich the graphite crucible from above and below, and a plurality of sample feeders for the graphite crucible are vertically arranged side by side. In addition to supplying the samples to the hoppers provided in each, and using the elemental analyzer having a lid that opens and closes the sample supply hole to each of the hoppers, using the same graphite crucible repeatedly for multiple samples Elemental analysis can be performed continuously, and not only the running cost of elemental analysis can be reduced, but also analysis time can be shortened and analysis labor can be simplified, and the same graphite crucible can be used repeatedly. That is, since the blank value of the graphite crucible to be used is constant, improvement in analysis accuracy can be achieved.

Furthermore, it is possible to use the graphite crucible as it is until the graphite crucible is broken, and repeat the above elemental analysis, thereby further reducing the running cost and the analysis time.

Then, according to the elemental analysis method of the present invention, by supplying the flux to any of the hoppers provided in each sample feeder, the elemental analysis according to the present invention can be performed using the flux, and if necessary. The flux can be reused accordingly.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional side view of an elemental analyzer, and FIG. 2 (A).
(F) is an explanatory view showing one procedure of elemental analysis. 4 ... upper electrode, 5 ... sample injection hole, 7 ... lower electrode,
9 ...... graphite crucible, 10, 16 ...... sample loading machines, 13, 18 ...... hopper, 20 ...... lid, n _1, n ₂ ...... _{Sample, n 1, n 2, a} , b, c, d , e
...... Sample supply hole.

Claims (2)

[Claims] 1. An upper electrode and a lower electrode that sandwich a graphite crucible from above and below, and a plurality of sample feeders for the graphite crucible are arranged side by side in a vertical direction. While supplying samples respectively,
Using an elemental analyzer having a lid that opens and closes sample supply holes to each hopper, the graphite crucible is electrically heated to melt the sample supplied to the graphite crucible, and the elements in the sample are analyzed. In the method, the lid is opened, and the graphite crucible is placed on the electrode surface of the lower electrode, and then the plurality of sample feeders are respectively fed with sample through the respective sample supply holes. After the above, the lid is closed and the elemental analyzer is placed under a gas seal, and the graphite crucible is degassed, and the sample is introduced by sliding the lowest hopper and communicating with the graphite crucible. The above-supplied sample is positioned immediately above the hole, the sample is put into the graphite crucible for elemental analysis, and subsequently, the samples supplied to the second and subsequent hoppers from the bottom are sequentially introduced. Elemental analysis, Elemental analysis method using repeat the graphite crucible and performing elemental analysis of each sample. 2. The elemental analysis according to claim 1, wherein the graphite crucible is degassed again prior to the second and subsequent introduction of the sample into the degassed graphite crucible. Method.