JPH09127028A - Fluorescent x-ray analytical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluorescent X-ray analytical apparatus which prevents a bad influence of the leak of a sample by fitting a base inside frame to a base outside frame in a measuring part, providing a sample cell base in which one end of the base inside frame is blocked up by an X-ray transmitting sheet which is sandwiched and bonded between them freely attachably and detachably to hold a sample cell. SOLUTION: An X-ray transmitting sheet 27 is placed on a face on the side of a rise part 30 at a base outer frame 25, and a base inside frame 26 is fitted onto it. The sheet 27 is pulled by the base inside frame 26 so as to be spread and stretched, and it is stretched and installed between the base outside frame 25 and the base inside frame 26 so as to partition a space 28 and a space 29. A sample cell base 24 which is assembled in this manner is placed on a measuring part 2 on a bench 1, and a sample cell 3 which houses a sample 23 inside, is set. In this state, the sample 23 is irradiated via the sheet 27 with X-ray from an X-ray tube 4, fluorescent X-rays which are excited by an element to be analyzed in the sample are detected by an X-ray detector 6, and their energy intensity is measured. Since the sheet 27 is stretched and installed on the cell base 24 in this manner, the cell base 24 acts as a saucer even when the sample 23 inside the cell 3 is leaked, and a bed influence is prevented.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an X-ray fluorescence analyzer.

[0002]

2. Description of the Related Art When performing a fluorescent X-ray analysis on a flowing sample such as a liquid or a powder, an X-ray having a bottom surface that transmits X-rays is used.
A sample cell made of a thin sheet having a low X-ray transmittance is set at a measurement site of a fluorescent X-ray analyzer, and the sample cell is irradiated with primary X-rays from below the measurement site. It is detected by a line detector.

FIG. 5 schematically shows the structure of a conventional X-ray fluorescence spectrometer. In FIG.
A turntable 4 on which the sample cell 3 is placed is provided at the measurement site 2 above the sample cell 3. Reference numeral 5 denotes an X-ray tube for irradiating the sample cell 3 with primary X-rays from below the measurement site 2, reference numeral 6 denotes an X-ray detector for detecting fluorescent X-rays generated by primary X-ray irradiation, and reference numeral 7 denotes fluorescent X-rays. Is the incident surface.

By the way, as the sample cell 3, a cell as shown in FIG. 4 has been conventionally used because it needs to accommodate a flowable sample and transmit primary X-rays. That is, in this figure, 8 is a cylindrical cell inner frame made of plastic such as polyethylene or metal, and annular protrusions 9, 10, 11 are provided on the outside thereof.
Are formed.

An inner frame cover 12 is formed by bending a soft plastic film, and has a circular bottom portion 13.
An annular rising portion 14 rising around the bottom portion 13, a folded portion 15 continuously provided from the upper end of the rising portion 14, and a flange portion 16 connected to the folded portion 15, the rising portion 14 and the folded portion 15. A space 17 into which the cell inner frame 8 can be completely inserted is formed between the two. A backing sheet 18 for reinforcement is attached to the back surface of the bottom portion 13 and the back surface of the flange portion 16.

Reference numeral 19 denotes an X-ray transparent sheet such as Mylar (trade name). Further, 20 is a cylindrical cell outer frame made of plastic such as polyethylene or metal, and a flange portion 21 is formed on the outside thereof, and a protruding portion 22 is formed on the inside thereof.

In order to fill a sample into the sample cell 3 made of such a member, first, the cell inner frame 8 is fitted into the space 17 of the inner frame cover 12, and the rising portion 14 and the folded portion of the inner frame cover 12 are folded. 15 is completely covered with the cell inner frame 8. Next, the sample is put into the space formed by the bottom portion 13 and the rising portion 14 of the inner frame cover 12, the X-ray permeable sheet 19 is covered from above, and the cell outer frame 20 is removed from above. It fits. by this,
The X-ray transparent sheet 19 is pulled by the cell outer frame 20 and spreads without wrinkling, and closes one end side of the cell inner frame 8.

Then, the analysis is performed as follows.
That is, as shown in FIG. 5, the sample cell 3 is set on the measurement site 2 with its upside down, and in that state, the primary X-rays from the X-ray tube 4 are transmitted through the X-rays of the sample cell 3. Irradiate the sample 23 in the sample cell 3 through the permeable sheet 19,
The fluorescent X-ray excited by the analytical element contained in the sample 23 is detected by the X-ray detector 6 and the energy intensity thereof is measured.

[0009]

By the way, in the above-mentioned conventional X-ray fluorescence analyzer, the sample cell 3 is incompletely assembled, or the sample cell 3 is placed in the measuring portion 2 while the sample 23 is placed inside. When the X-ray transmissive sheet 19 is damaged by hitting the other part of the measurement site 2 when it is set to the position, the sample 23 in the sample cell 3 leaks out, and thereby the sample 23 below the measurement site 2 is leaked. Located X-ray detector 6 or X
There were cases where the function of the wire tube 4 was hindered and these were contaminated.

Incidentally, such a problem is not limited to the case of using the sample cell 3 shown in FIG.
And a cell inner frame 8 mounted inside the cell outer frame 20.
The sample cell 3 composed of the X-ray permeable sheet 19 sandwiched between the outer cell frame 20 and the inner cell frame 8 and closing one end of the inner cell frame 8 was measured as shown in FIG. It also occurs when it is set on site 2.

The present invention has been made in consideration of the above-mentioned matters, and an object thereof is that the X-ray transmissive sheet of the sample cell is damaged due to incomplete assembly of the sample cell or an unexpected accident. Thus, even if the sample in the sample cell leaks out, it is possible to provide an X-ray fluorescence analyzer that does not have an adverse effect on the X-ray detector or the X-ray tube located below the measurement site. is there.

[0012]

In order to achieve the above object, according to the present invention, there are provided a cell outer frame, a cell inner frame mounted inside the cell outer frame, and a cell outer frame and a cell inner frame. An X-ray transmissive sheet that is sandwiched between the cell inner frame and one end side of the cell inner frame and is configured to store a sample in the cell inner frame is set to the measurement site, and the measurement site In a fluorescent X-ray analysis device configured to irradiate primary X-rays from below toward the sample cell, an outer frame of the stand, an inner frame mounted inside the outer frame of the stand, and A sample cell base made up of an X-ray transparent sheet sandwiched between an outer frame and an inner frame and closing one end of the inner frame is detachably provided, and the sample cell is held on the sample cell base. I am trying to let you.

According to the X-ray fluorescence analyzer having the above structure, even if the sample leaks from the sample cell, the leaked sample causes the X located below the measurement site.
It is possible to prevent the radiation detector, the X-ray tube, and the like from being harmed or contaminated, and to reliably perform the analysis.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings.

First, FIG. 1 schematically shows a main part of an example of an X-ray fluorescence analyzer according to the present invention. In this figure, the same parts as those shown in FIG. 4 and FIG. The same thing is shown. In FIG. 1, reference numeral 24 denotes a sample cell table detachably provided to the measurement site 2 on the bench 1, and an example of the configuration is shown in FIG.

As shown in FIG. 2, the sample cell base 24 includes a base outer frame 25, a base inner frame 26 mounted inside the base outer frame 25, and the base outer frame 25 and the base inner frame 26. And an X-ray transmissive sheet 27 which is sandwiched between and and closes one end side of the base inner frame 26. The outboard frame 25 and the inboard frame 26 are formed in an annular body (circular shape) having spaces 28 and 29 having the same diameter, and are made of, for example, aluminum.

An annular rising portion 30 having an appropriate height is provided upright on the outer edge portion of the stand outer frame 25. Further, the inner frame 26 has a slightly smaller diameter than the outer frame 25, and when the X-ray transparent sheet 27 is attached to the outer edge of the inner frame 26, the inner frame 26 is in close contact with the inner surface of the rising portion 30 and the sample cell 3 An annular guide portion 32 having a tapered inner peripheral surface 31 (see FIG. 1) which is formed so as to widen toward the upper side so that it can be guided, is formed inside the guide portion 32. , On the inner edge,
The annular protruding portion 33 is formed concentrically with the guide portion 32.

As shown in FIG. 1, the dimensions of the outer frame 25 and the inner frame 26 are such that the upper end of the annular protrusion 33 corresponds to the bottom surface of the sample cell 3, particularly the lower end of the cell inner frame 8. As described above, the sample cell 3 can be set, and in this set state, the cell outer frame 20 of the sample cell 3 is set so as to be positioned between the rising portion 31 and the annular protruding portion 33. The outer diameter of the annular protrusion 33 is slightly smaller than the inner diameter of the cell outer frame 20, and more preferably,
With the sample cell 3 placed on the upper end of the annular protrusion 33, the lower end of the cell inner frame 8 can be regulated so as not to come off the upper end of the annular protrusion 33 even if the sample cell 3 is horizontally displaced. I wish I had it. Further, it is preferable that the guide portion 32 is higher than the annular protruding portion 33.

The X-ray transmissive sheet 27 is made of the same material as the X-ray transmissive sheet 19 used in the sample cell 3, and the X-ray transmissive sheet 27 is placed on the rising portion 30 side of the stand outer frame 25. On the surface of the table, and by fitting the inner frame 26 into the outer frame 25 of the table from above and mounting it, X
The line permeable sheet 27 is stretched without being wrinkled by being stretched by the base inner frame 26 and is stretched between the base inner frame 26 and the base outer frame 25 so as to partition the spaces 28 and 29. .

Next, the operation of the X-ray fluorescence analyzer having the above-mentioned structure will be described. At the time of analysis, the sample cell base 24 assembled as described above is placed on the measurement site 2 on the bench 1. Then, the sample cell 3 separately assembled so as to accommodate the sample 23 therein is set on the measurement site 2 such that the lower end of the cell inner frame 8 corresponds to the upper end of the annular projection 33, and in this state. The sample 23 in the sample cell 3 is irradiated with primary X-rays from the X-ray tube 4 via the X-ray permeable sheet 27 of the sample cell table 24 and the X-ray permeable sheet 19 of the sample cell 3. Is detected by the X-ray detector 6 and the energy intensity thereof is measured.

In the embodiment described above, the sample cell stand 24
Since the X-ray transmissive sheet 27 is stretched over, the assembly of the sample cell 3 is incomplete, or the X-ray transmissive sheet 1
Even if the sample 23 in the sample cell 3 leaks out due to damage to the sample cell 9, the sample cell base 24 serves as a tray, and the leaked sample causes the X-ray detector 6 and the X-ray detector 6 located below. It is possible to prevent the wire tube 4 and the like from being harmed or polluted, so that the analysis can be reliably performed.

Since the sample cell base 24 is detachable from the measurement site 2 of the bench 1 and is easy to assemble and disassemble, the X-ray transmissive sheet 27 can be replaced and the outer frame of the base can be removed. 25, maintenance such as cleaning of the base inner frame 26 can be easily performed.

Further, since the guide portion 32 is provided upright on the sample cell base 24, the sample cell 3 in which the cell outer frame 20 projects downward as compared with the cell inner frame 8 is set in a predetermined state. In such a case, the lower portion of the cell outer frame 20 may come into contact with the guide portion 32 so that the inclination of the sample cell 3 can be regulated. Damage due to contact can be effectively prevented, and the sample cell 3 can be easily and reliably set at a predetermined position.

Furthermore, since the sample cell 3 is set so that the lower end of the cell inner frame 8 corresponds to the upper end of the annular protrusion 33 of the sample cell base 24, unlike the conventional case, the sample measurement surface A and the X-ray are different. The distance from the detector 6 is always constant, and therefore the degree of contact of the fluorescent X-rays with air does not fluctuate each time the sample cell 3 is set, so that no analysis error occurs.

FIG. 3 shows another embodiment of the present invention. In this figure, 34 is a sample cell base detachably provided on the measurement site 2 above the bench 1, and the sample cell base 34 is mounted on the sample cell base 34. Is different from the sample cell base 24 in the above-mentioned embodiment, there is no annular protrusion 33, and the sample cell 3 is in a state where the cell inner frame 8 is in direct contact with the plane of the base inner frame 26 of the sample cell base 34. Placed. The other configurations are the same as those of the sample cell base 24.

Also in this embodiment, the sample cell base 34
Since the X-ray transmissive sheet 27 is stretched over, the assembly of the sample cell 3 is incomplete, or the X-ray transmissive sheet 19 is attached.
Even if the sample 23 in the sample cell 3 leaks out due to damage to the sample cell, the sample cell base 34 serves as a saucer,
The leaked sample is prevented from damaging or contaminating the X-ray detector 6 and the X-ray tube 4 located below, and reliable analysis can be performed.

The sample cell base 34 is the bench 1
The X-ray transparent sheet 2 is detachable from the measurement site 2 of the X-ray, and is easy to assemble and disassemble by itself.
Maintenance such as replacement of 7 and cleaning of the outer frame 25 and the inner frame 26 can be easily performed.

Although the sample cell base 34 does not have a function of guiding the sample cell 3, the inner frame 8 of the sample cell 3 defining the sample measurement surface A is the inner frame 26 of the sample cell base 34.
The sample measurement surface and the X-ray detector 6
Since the distance between and is always constant, the degree of contact of the fluorescent X-rays with air does not fluctuate with each setting of the sample cell 3, so that no analysis error occurs.

In this embodiment, the cell outer frame 2
The lower end of 0 does not project downward from the lower end of the cell inner frame 8, but the lower ends of both 8 and 20 are at the same time the sample cell base 3
It may be configured so as to come into contact with the plane of the in-stand frame 26 of No. 4.

The present invention is not limited to the above-mentioned respective embodiments, and, for example, as the sample cell 3, the cell outer frame 2 is used.
0 and the cell inner frame 8 mounted inside the cell outer frame 20
And an X-ray transmissive sheet 19 that is sandwiched between the cell outer frame 20 and the cell inner frame 8 and closes one end side of the cell inner frame 8. Then, the sample cell base 2
4, 34 may be incorporated in a turntable or the like. Further, in the embodiment shown in FIG. 1, the lower end of the cell inner frame 8 may be made to project downward from the lower end of the outer frame 20, and the lower ends of both 8 and 20 are simultaneously formed in the annular shape of the base inner frame 26. It may be configured to abut the protrusion 33.

[0031]

As described above, according to the present invention, even if a sample leaks from the sample cell, the leaked sample detects X-rays located below the measurement site. It is possible to prevent the damage of the vessel and the X-ray tube, and the damage of the tube. And according to this invention, an analysis can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a main part of an X-ray fluorescence analyzer according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an example of a sample cell table used in the apparatus.

FIG. 3 is a diagram schematically showing a main part of an X-ray fluorescence analyzer according to another embodiment of the present invention.

FIG. 4 is an exploded perspective view showing an example of a sample cell used for X-ray fluorescence analysis.

FIG. 5 is a view schematically showing a main part of a conventional X-ray fluorescence spectrometer.

[Explanation of symbols]

2: Measurement site, 3: Sample cell, 8: Cell inner frame, 19: X
Line permeable sheet, 20: cell outer frame, 24: sample cell table,
25 ... Outer frame, 26 ... Inner frame, 27 ... X-ray transparent sheet, 34 ... Sample cell stand.

Claims (1)

[Claims] 1. A cell outer frame, a cell inner frame to be mounted inside the cell outer frame, and an X which is sandwiched between the cell outer frame and the cell inner frame and closes one end side of the cell inner frame. A sample cell composed of a line-transparent sheet and configured to accommodate a sample in a cell inner frame is set at a measurement site, and primary X-rays are irradiated from below the measurement site toward the sample cell. In the X-ray fluorescence analyzer described above, a stand outer frame, a stand inner frame mounted inside the stand outer frame, a stand outer frame and a stand inner frame are sandwiched between the stand outer frame and the stand outer frame at the measurement site. An X-ray fluorescence analyzer, characterized in that a sample cell base made of an X-ray transmissive sheet for closing one end side of an inner frame is detachably provided, and the sample cell is held on the sample cell base.