JP4838821B2 - Sample holder for fluorescent X-ray analysis and fluorescent X-ray analysis method and apparatus using the same - Google Patents

Description

  The present invention relates to a sample holder for fluorescent X-ray analysis used for pre-processing a liquid sample and analyzing a contained component by fluorescent X-ray analysis, and an X-ray fluorescence analysis method and apparatus using the same.

  2. Description of the Related Art Conventionally, as a technique for preprocessing a liquid sample and subjecting the contained component to X-ray fluorescence analysis, there is a filter paper drip method in which the contained component is concentrated and retained by dropping the liquid sample onto a filter paper and drying it. However, since the thickness of the filter paper is several hundred μm, a lot of primary X-ray scattered rays are generated and the background becomes high. In order to suppress the background caused by the scattered X-ray, a vapor deposition film such as carbon is formed on a polymer film having a thickness of about 0.5 μm, and a liquid sample is dropped on the portion where the vapor deposition film is formed and dried. There is a technique for retaining the contained components by (Patent Document 1). However, since the vapor deposition film is extremely thin and the diameter of the vapor deposition film is about 2 mm in order to uniformly condense the liquid sample, the amount that can be dripped at a time is equal to or less than the dripping amount in the case of filter paper. Therefore, although the background is lowered by using a polymer film and a vapor deposition film thinner than the filter paper, the intensity of fluorescent X-rays to be obtained does not increase, so that the detection limit is not sufficiently improved.

  Therefore, as a liquid sample holder that can sufficiently improve the detection limit by suppressing the background and uniformly generating fluorescent X-rays with higher intensity, a ring-shaped pedestal and a peripheral portion held by the pedestal And a hydrophobic film having a transmission part for transmitting X-rays, and a sheet-like liquid absorbent material affixed to the transmission part of the hydrophobic film, and the liquid sample is dropped onto the liquid absorbent material There is a liquid sample holder that holds the above-mentioned components by being dried (Patent Document 2). In this liquid sample holder, since the components contained in the liquid sample are held in the liquid absorbent material, a large amount of liquid sample of about 500 μl can be instilled at one time, and the liquid sample is repeatedly instilled and dried. Therefore, a sample of several ml can be drip-dried, which is suitable for measurement of a sample with a small amount of the element to be measured.

The liquid sample holder described in Patent Document 1 forms a vapor deposition film such as carbon on a polymer film, and the liquid sample holder described in Patent Document 2 uses a sheet-like liquid absorbent material affixed to a hydrophobic film. Therefore, when primary X-rays are irradiated, impure lines of light elements such as Mg, Al, P, and S contained in the carbon vapor deposition film and the liquid absorbent material are generated. Accordingly, a sample holder which does not have a carbon vapor deposition film or a liquid absorbent and is formed by forming a recess having a diameter of 2 mm in an extremely thin polymer film is sold by MOTTEK.
JP 2003-90810 A JP 2005-012889 gazette

  However, since the sample holder of MOXTEK is manufactured by molding a polymer film, the cross-sectional view 10A showing the state of the sample holder 50 before drying the instilled liquid sample S and the infused liquid sample S. As shown in the cross-sectional view 10B showing the state of the sample holder 50 after drying, the recess 54 into which the liquid sample S is instilled is recessed even after the liquid sample S is dried, as before drying. In the drying stage of the liquid sample S, the polymer film 53 is slightly deformed, and the height of the component S1 of the liquid sample held in the depression 54 by the individual sample holder 50 varies, and the detected fluorescent X-rays. The intensity of fluctuates. Therefore, it cannot be analyzed with high accuracy.

  The present invention has been made in view of the above-mentioned conventional problems. A sample holder for fluorescent X-ray analysis used for pre-processing a liquid sample and analyzing the contained components by fluorescent X-ray analysis, and fluorescent X-ray analysis using the same An object of the method and apparatus is to eliminate impurity lines from the sample holder for fluorescent X-ray analysis, suppress the background, improve the detection limit, and improve the analysis accuracy.

    In order to achieve the above object, the sample holder for fluorescent X-ray analysis of the present invention is a sample holder for fluorescent X-ray analysis used for pre-processing a liquid sample and analyzing the contained components by fluorescent X-ray analysis. And a heat-shrinkable film having a thickness of 12 μm or less having a peripheral part held by the base with a predetermined tension and a transmission part for transmitting X-rays, and a depression is formed in the transmission part. It is formed, and the liquid sample is dropped into the depression of the transmission part and dried, so that the transmission part becomes flat and the contained component is held.

  According to the sample holder for fluorescent X-ray analysis of the present invention, the permeation portion of the heat-shrinkable film irradiated with primary X-rays has a liquid sample holder such as a conventional carbon vapor deposition film or a liquid absorbent material. In addition, since the liquid sample is held in the depression formed in the transmission part of the heat-shrinkable film, no impure line is generated even when the primary X-ray is irradiated. In addition, since the liquid sample holding material is not provided, there is almost no generation of scattered radiation due to the irradiated primary X-rays, and the background can be significantly suppressed. These can sufficiently improve the detection limit. In addition, since the liquid sample is dried, the transmission portion becomes flat, and the sample height at the time of measurement is always a constant height, so that an accurate analysis can be performed.

  In the sample holder for fluorescent X-ray analysis of the present invention, the heat-shrinkable film is preferably made of one selected from the group consisting of polyester, polypropylene and polyimide.

  The fluorescent X-ray analysis method of the present invention is a fluorescent X-ray analysis method using the sample holder for fluorescent X-ray analysis of the present invention, wherein the liquid sample is dropped into the depression of the transmission part and dried, 2 is generated by flattening the transmissive part, holding a component contained in the liquid sample in a part of the transmissive part, and irradiating the part of the transmissive part with primary X-rays. The intensity of the next X-ray is measured.

  The X-ray fluorescence analyzer of the present invention is an X-ray fluorescence analyzer using the sample holder for X-ray fluorescence analysis of the present invention, and the components contained in the liquid sample are removed by dripping and drying the liquid sample. An X-ray source that irradiates a primary X-ray to a portion that was a depression of the held transmission portion, and a detection unit that measures the intensity of secondary X-rays generated from the portion that was a depression of the transmission portion. .

  According to the fluorescent X-ray analysis method and apparatus of the present invention, since the fluorescent X-ray analysis sample holder of the present invention is used, the same effects as the fluorescent X-ray analysis sample holder of the present invention can be obtained.

  Hereinafter, the sample holder for fluorescent X-ray analysis which is 1st Embodiment of this invention is demonstrated. As shown in FIG. 1, this sample holder 1 is used for pre-processing a liquid sample and analyzing the contained components by fluorescent X-ray analysis, and stably holds the heat-shrinkable film 3. A ring-shaped pedestal 2 and a heat shrinkable film 3 having a peripheral part 3a held by the pedestal 2 with a predetermined tension and a transmission part 3b for transmitting X-rays are provided. When the liquid sample S is dropped into the depression 3c, which is a depression in the transmission part 3b, and dried, the transmission part 3b is flattened, and the components contained in the liquid sample S are concentrated in the depression 3c. And hold. For example, the base 2 has a ring shape with an outer diameter of 50 mm, an inner diameter of 30 mm, and a thickness of 1 mm, and is made of a resin material such as polyethylene or polystyrene. For example, the heat-shrinkable film 3 is made of polyester, polypropylene, polyimide or the like having a thickness of 12 μm or less, preferably 2 to 6 μm, and the material is more preferably polypropylene.

  FIG. 2 shows a longitudinal cross-sectional view. Here, the heat-shrinkable film 3 is a circle having the same diameter as the outer diameter of the pedestal 2, and the peripheral portion 3 a is held on the pedestal 2 with a predetermined tension. A method of holding at a predetermined tension will be described later. The part excluding the peripheral part 3a is a transmission part 3b for transmitting X-rays, and a recess 3c is formed in the transmission part 3b. The depression 3c is, for example, a circle having a depth of about 1 mm and a diameter of about 10 mm in plan view. The shape of the dent 3c is not limited to the above, but may be any shape that can hold an instilled liquid sample such as an ellipse or a rectangle in plan view, and can be flattened by heat contraction when heated. In addition, the dimensions are not limited to the above, and a depth of 0.5 to 2 mm and a maximum length in a plan view of 5 to 20 mm are preferable, and a ratio of the depth to the maximum length is preferably 1: 3 to 1:20. 1: 8-1: 15 are more preferable. In FIG. 1 and FIG. 2, since the inner periphery of the base 2 is hidden under the heat-shrinkable film 3, it is shown with a broken line, but it actually shows through.

  A method for holding the heat-shrinkable film 3 on the base 2 with a predetermined tension will be described. As shown in FIG. 4A, which is a first manufacturing procedure of the sample holder 1, the heat-shrinkable film 3 is placed on the upper surface 21 a of the cylinder 21 having the same inner and outer diameter as the base 2. Next, as shown in FIG. 4B, which is a second manufacturing procedure of the sample holder 1, the extension ring 22 is fitted into the cylinder 21 from above the covered heat-shrinkable film 3, and downward along the side surface of the cylinder 21. The heat-shrinkable film 3 is stretched so as to be tightly stretched on the upper surface 21a of the cylinder 21. The extension ring 22 has an inner diameter that is slightly smaller than the outer diameter of the cylinder 21 and is made of, for example, elastic rubber or a resin material, and is in close contact with the heat-shrinkable film 3 due to its elasticity. Because it slides while pulling, it can be stretched in a taut state.

  Next, as shown in FIG. 4C, which is the third manufacturing procedure of the sample holder 1, for example, spray glue (components are acrylic rubber (10%), organic solvent (54%) and isohexane gas (36%), The high-pressure gas for injection is sprayed with dimethyl ether on one surface of the pedestal 2, and the outer periphery of the pedestal 2 is pasted in accordance with the outer periphery of the upper surface 21 a of the cylinder with the heat-shrinkable film 3 extended. Next, when the expansion ring 22 is removed from the cylinder 21 and the heat-shrinkable film 3 protruding from the outer periphery of the pedestal 2 is cut out, as shown in FIG. The thin film ring 5 in which the conductive film 3 is held on the base 2 with a predetermined tension is formed.

  The method for stretching the heat-shrinkable film 3 in a tensioned state is not limited to the above method, and other methods may be used. For example, one heat-shrinkable film 3 is covered and fixed from above the cylinder of an extension plate having a plurality of cylinders with a reduced cylinder length of the cylinder 21 on the plate. Thereafter, in the same manner as described above, the base 2 is attached to the heat-shrinkable film 3 on the upper surface of each of the plurality of cylinders, and the heat-shrinkable film 3 protruding from the outer periphery of the base 2 is cut off.

  Next, a method for forming the recess 3c in the thin film ring 5 will be described. As shown in FIG. 4E, for example, a ring-shaped depression forming jig 23 having a thickness of 1 mm, an outer diameter of 29 mm, and an inner diameter of 10 mm is prepared. The recess forming jig 23 is preferably made of a resin material such as polyethylene or polystyrene which is the same material as the base 2. Next, for example, a pressing jig 24 made of a synthetic resin such as polyethylene or Teflon (registered trademark) is prepared with a cylinder having a diameter of 10 mm, a length of 100 mm, and one end surface being a hemispherical surface. Using the prepared annular recess forming jig 23 and pressing jig 24, the recess 3c is formed as follows.

  As shown in FIG. 4E, which is a longitudinal sectional view of the fifth manufacturing procedure of the sample holder 1, the recess forming jig 23 is placed on a flat table 30, and the heat-shrinkable film 3 is placed thereon from above. The thin-film ring 5 is placed so that the hollow forming jig 23 enters the inner periphery of the base 2 of the thin film ring 5. As shown in FIG. 4F, which is a plan view of the fifth manufacturing procedure of the sample holder 1, the depression forming tool 23 can be seen through the transmission part 3 b. As shown in FIG. 4G, which is the sixth manufacturing procedure of the sample holder 1, the end surface 24a of the hemispherical surface of the pressing jig 24 is set downward and the outer periphery thereof is aligned with the inner periphery of the depression forming jig 23 so that the upper side of the thin film ring 5 Then, the transmission part 3b of the heat-shrinkable film 3 is pressed, and the pressing jig 24 is lifted. When the transmission part 3b is pressed, a recess 3c is formed in the transmission part 3b as shown in FIG. The method for forming the depression 3c is not limited to the above method, and other methods such as blowing clean air or nitrogen gas to the transmission part 3b may be used.

  In the fluorescent X-ray analysis using the sample holder 1, the liquid sample S is dropped into the recess 3c as shown in FIG. Here, since the recess 3c is recessed from the surrounding transmission part 3b, the liquid sample S does not roll from the recess 3c to the periphery, and is stably held in the recess 3c. Then, when the dropped liquid sample S is heated and dried to 40 to 60 ° C. with an appropriate heating and drying device, the heat shrinkage of the heat-shrinkable film 3 of the transmission part 3 b generates the same level of tension as the original and transmits. The part 3b becomes flat. As a result, as shown in the longitudinal sectional view of FIG. 3, the portion 3d that was the depression 3c has the same height as the surrounding transmission part 3b, and the component 3d contained in the liquid sample S is added to the portion 3d that was the depression 3c. S1 is held.

  As the heating and drying apparatus for drying the liquid sample S that has been instilled on the sample holder 1, a heating lamp and a heating dryer that are commercially available as physics and chemistry equipment are preferable. It is more preferable to use a sample drying apparatus (trade name: Ultra Dry) described in Japanese Patent Application No. 2007-220016 because the liquid sample can be dried without being contaminated. The sample holder 1 is placed on the sample stage of the fluorescent X-ray analyzer, and the portion 3d that is the depression 3c of the transmission part 3b that holds the component S1 of the liquid sample S is irradiated with primary X-rays to fluoresce. Perform X-ray analysis. A method for placing the sample holder 1 on the sample stage of the X-ray fluorescence analyzer will be described later.

  The measurement data measured using the sample holder 1 of the present embodiment with the measurement solution dropped to 500 μl are shown in FIGS. 6 and 7. FIG. 6 shows measurement data for each light element, and FIG. 7 is a qualitative analysis chart for heavy elements. The measurement solution is a commercially available mixed standard solution containing Na, Mg, Al, Si, P, Cl, K, Ca, Ba, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Tl, and Pb. Diluted with distilled water, the concentrations of K and P were adjusted to 5 ppm (weight ppm, hereinafter the same), Si was adjusted to 5 ppm as SiO2, and the concentrations of other elements were adjusted to 1 ppm. According to the measurement data (FIGS. 6 and 7), it can be seen that the impure line from the sample holder 1 is eliminated, the generation of scattered radiation hardly occurs, and the background can be greatly suppressed.

  As described above, according to the sample holder 1 for fluorescent X-ray analysis of the present embodiment, a liquid such as a carbon vapor deposition film or a liquid absorbent is provided in the transmission part 3b of the heat-shrinkable film irradiated with the primary X-rays. It does not have a sample holding material, and impure lines due to light elements such as Mg, Al, P, and S contained in the filter paper of a conventional sample holder do not occur. In addition, since the liquid sample holding material is not provided, there is almost no generation of scattered radiation due to the irradiated primary X-rays, and the background can be significantly suppressed. By these, the detection limit can be sufficiently improved, and the effect is particularly remarkable in light elements.

  When the dropped liquid sample S is dried, the heat shrinkage of the heat-shrinkable film 3 of the transmission part 3b generates a tension of the same level as the original and the transmission part 3b becomes flat. As a result, as shown in the longitudinal sectional view of FIG. 3, the portion 3d that was the depression 3c has the same height as the surrounding transmission part 3b, and the component 3d contained in the liquid sample S is added to the portion 3d that was the depression 3c. S1 is held. As described above, since the sample height at the time of measurement is always a constant height, an accurate analysis can be performed. Moreover, since the carbon vapor deposition film and the liquid absorbing material are not provided, the cost of the fluorescent X-ray analysis sample holder 1 and the fluorescent X-ray analysis method and apparatus using the same can be reduced.

  Next, a fluorescent X-ray analysis method according to the second embodiment of the present invention will be described. An X-ray fluorescence analyzer 10 used in this analysis method is the third embodiment of the present invention, and as shown in FIG. 8, is an apparatus using the sample holder 1 for X-ray fluorescence analysis of the first embodiment. The sample holder 17 is a sample stage on which the sample holder 1 is mounted directly or via the sample holder 18, and the liquid sample S is dropped and dried, so that the component S1 of the liquid sample S is removed. An X-ray source 11 such as an X-ray tube that irradiates the primary X-ray 12 to the portion 3d that was the held depression 3c, and a secondary X-ray 15 such as a fluorescent X-ray generated from the portion 3d that was the depression 3c. And a detecting means 16 such as an X-ray detector for measuring the intensity.

  The fluorescent X-ray analysis method of the second embodiment using this apparatus is a method using the fluorescent X-ray analysis sample holder 1 of the first embodiment, and as described above, a liquid sample is placed in the dent 3c of the transmission part. By dripping and drying S, the transmission part 3b is flattened and the component S1 of the liquid sample S is held in the portion 3d that was the depression 3c. After this pretreatment, the entire sample holder 1 is removed. The sample holder 18 is placed on the sample stage 17 by placing it on the opening of a cylindrical sample holder (hollow cup) 18 made of aluminum or titanium. Such a sample holder 18 is used in order to reduce the background so that objects do not come near the back side of the transmission part 3b, and on the inner surface of the apparatus of the primary X-ray 12 that has passed through the back side of the transmission part 3b. This is to reduce the influence of scattered radiation. The sample holder 18 may have a simple cylindrical shape without a bottom.

  As shown in FIG. 9, when the sample stage 17 is provided with a through hole 17 a having the same size as the hole of the pedestal 2, the sample holder 1 is directly attached to the sample holder 18 without using the sample holder 18. It may be placed on the stage 17.

  As described above, the secondary X-rays generated by irradiating the primary X-ray 12 to the portion 3d that was the depression 3c holding the component S1 of the liquid sample S of the sample holder 1 placed on the sample stage 17 are irradiated. An intensity of 15 is measured.

  The above is the case of so-called upper surface irradiation in which the primary X-ray 12 is irradiated from above the component S1 of the sample S, but the case of so-called lower surface irradiation in which the primary X-ray is irradiated from below the component S1 of the sample S. Can also be used.

  According to the method and apparatus of the second and third embodiments, since the fluorescent X-ray analysis sample holder 1 of the first embodiment is used, the same operational effects as those of the first embodiment can be obtained.

It is a perspective view of the sample holder for fluorescent X-ray analysis which is a 1st embodiment of the present invention. It is a longitudinal cross-sectional view of the sample holder. It is a longitudinal cross-sectional view which shows the holding state of the content component of the sample by the sample holder. It is a perspective view which shows the 1st manufacture procedure of the sample holder. It is a perspective view which shows the 2nd manufacture procedure of the sample holder. It is a perspective view which shows the 3rd manufacture procedure of the sample holder. It is a perspective view which shows the 4th manufacturing procedure of the sample holder. It is a longitudinal cross-sectional view which shows the 5th manufacture procedure of the sample holder. It is a top view which shows the 5th manufacture procedure of the sample holder. It is a longitudinal cross-sectional view which shows the 6th manufacturing procedure of the sample holder. It is a longitudinal cross-sectional view which shows the 7th manufacturing procedure of the sample holder. It is a longitudinal cross-sectional view which shows the holding state of the liquid sample by the sample holder. Measurement data for light elements. It is a qualitative analysis chart of heavy elements. It is the schematic of the fluorescent X ray analyzer which is 3rd Embodiment of this invention. It is the longitudinal cross-sectional view which mounted the sample holder of 1st Embodiment directly on the sample stage of the apparatus. It is sectional drawing which shows the state before drying of the liquid sample of the conventional sample holder. It is sectional drawing which shows the state after the drying of the liquid sample of the sample holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluorescent X-ray analysis sample holder 2 Base 3 Heat-shrinkable film 3a Peripheral portion 3b Permeation portion 3c Depression 3d Recessed portion 10 Fluorescent X-ray analyzer 11 X-ray source 12 Primary X-ray 15 Secondary X-ray 16 Detection means S Liquid sample S1 Components contained in the liquid sample

Claims (4)

A sample holder for fluorescent X-ray analysis used for pre-processing a liquid sample and analyzing the contained components by fluorescent X-ray analysis,
A ring-shaped pedestal;
It has a transmitting portion for transmitting the peripheral portion and the X-ray which is held at a predetermined tension on the seat, the thickness of 12μm or less of the heat that is extended taut by being held at the predetermined tension With shrinkable film,
Said predetermined tension about the same tension caused by heat shrinkage of the heat shrinkable film by heating, and a recess having a shape becomes flat is formed on the transmissive portion, the liquid sample in a recess of the transmission part A sample holder for fluorescent X-ray analysis that retains the above-mentioned components while flattening the transmission part by dropping and heat drying. In claim 1,
A sample holder for fluorescent X-ray analysis, wherein the heat-shrinkable film is one selected from the group consisting of polyester, polypropylene and polyimide. A fluorescent X-ray analysis method using the fluorescent X-ray analysis sample holder according to claim 1 or 2,
By dropping the liquid sample into the depression of the transmission portion and drying by heating , the transmission portion is flattened, and the components contained in the liquid sample are held in the portion that was the depression of the transmission portion,
A fluorescent X-ray analysis method for measuring the intensity of secondary X-rays generated by irradiating primary X-rays to a portion that is a depression of the transmission part. A fluorescent X-ray analysis apparatus using the fluorescent X-ray analysis sample holder according to claim 1 or 2,
An X-ray source that irradiates primary X-rays to a portion that was a depression of the transmission part that holds the components contained in the liquid sample by being dropped and heated and dried;
A fluorescent X-ray analyzer comprising: detection means for measuring the intensity of secondary X-rays generated from a portion that was a depression of the transmission part.

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