JP2006078386A - Powder sample molding method for x-ray fluorescence analysis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pretreatment method which enables measurement of light elements on a trace amount of powder samples of approximately a few tens of milligrams by X-ray fluorescence analyses, and easily recovering the samples after the analyses. <P>SOLUTION: For X-ray fluorescence analyses, a small amount of powder samples 1A is pressed and molded with a single sheet of polymeric film 2, in the direction of the thickness of the high molecular film 2 and is adhered to the high molecular film 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for pressure-molding a minute amount of a powder sample to be subjected to fluorescent X-ray analysis.

  Since a small amount of a powder sample of about several tens mg is subjected to fluorescent X-ray analysis, even if only the powder sample is pressure-molded, it is broken only by lifting and cannot be handled. In order to cope with this, there are conventionally two preprocessing methods. The first method is a method in which a powder sample is placed in a recess provided in a pellet of boric acid or cellulose and the whole is pressure-molded and integrated, and the second method is a method of combining two polymer films. In this method, a powder sample is sandwiched between and held.

  However, in the first conventional method, since the sample is not covered with a film or the like, the fluorescent X-ray from the light element can be detected and measured without being attenuated, but the sample that has been a powder is formed by pressure molding. Since it is integrated with the pellet, it is difficult to recover the sample after analysis. On the other hand, in the second conventional method, the powder sample can be taken out from between the polymer films after the analysis and can be easily recovered. However, since the fluorescent X-rays from the light elements are attenuated by the polymer film, Measurement is difficult. In other words, for powder samples that can be collected only in a few tens of mg, pre-processing that meets demands for measuring light elements by fluorescent X-ray analysis and then collecting the samples for further chemical analysis There is no way.

  The present invention has been made in view of the above-described conventional problems, and a pretreatment method capable of measuring a light element by fluorescent X-ray analysis on a small amount of powder sample of about several tens of mg and easily recovering the sample after the analysis. The purpose is to provide.

  In order to achieve the above-mentioned object, the present invention is to form a small amount of powder sample by pressure molding in the thickness direction of the polymer film together with one polymer film in order to use for fluorescent X-ray analysis. This is a powder sample forming method to be adhered.

  According to the present invention, since the powder sample is pressure-molded into a plate shape and one surface is attached to the polymer film, it is easy to hold the sample facing up so that it does not come off from the polymer film due to its own weight. It can be handled easily, and it won't collapse just by lifting. And since the sample is exposed on the side not attached to the polymer film, measurement is possible without attenuating fluorescent X-rays from light elements. Furthermore, after the analysis, the sample can be easily recovered simply by peeling it from the polymer film.

  In this invention, it is preferable that the said polymer film consists of polyester, a polypropylene, or a polyimide, and thickness is 10 micrometers or less.

  Hereinafter, a powder sample forming method according to an embodiment of the present invention will be described with reference to the drawings. In this method, first, as shown in FIG. 1, a single polymer film 2 is placed on the lower pressurizing jig 4a, and a trace amount, for example, 40 mg of a powder sample 1A is placed thereon. As the polymer film 2, a film made of polyester, polypropylene or polyimide having a high X-ray permeability, for example, a thickness of 5 μm can be used. The polymer film 2 is, for example, circular and has a diameter slightly larger than that of a sample 1B (FIG. 2) that assumes a disk shape after pressure molding. In all the drawings, the thicknesses of the films 2 and 5c and the molded sample 1B are exaggerated for easy illustration and understanding, and the dimensional relationship is not accurate.

  Next, as shown in FIG. 2, the upper pressurizing jig 4b is lowered, and the powder sample 1A (FIG. 1) is put together with the polymer film 2 in the thickness direction of the polymer film 2 (vertical direction in FIG. 2). For example, it is pressure-molded at 150 kN to be solidified into a disk shape and attached to the polymer film 2. At this time, the diameter of the molded sample 1B is, for example, 13 mm.

  Next, the upper pressurizing jig 4b is raised and held with the sample 1B facing upward so that the molded sample 1B does not peel off from the polymer film 2 due to its own weight, as shown in FIG. Then, it is taken out from the lower pressurizing jig 4a. Since one side of the molded sample 1B is attached to the polymer film 2, if the entire sample 1B is held as the molded sample 3 with the sample 1B facing up, the sample 1B can be easily handled and simply lifted up. Will not collapse.

  In FIG. 1, the powder sample 1A is placed on the lower pressure jig 4a, and the polymer film 2 is placed over the powder sample 1A. As shown in FIG. 4b may be lowered, and the powder sample 1A (FIG. 1) may be pressed together with the polymer film 2 in the thickness direction of the polymer film 2 (vertical direction in FIG. 2) to adhere to the polymer film 2. . In this case, since the molded sample 1B is under the polymer film 2, the entire pressurizing jigs 4a and 4b are turned upside down with the sample 1B and the polymer film 2 sandwiched therebetween, as described above. Then, the molded sample 3 is taken out from the pressure jigs 4a and 4b.

  When the molded sample 3 thus pretreated is subjected to fluorescent X-ray analysis, it is preferably placed on the sample holder 5 as shown in FIG. The sample holder 5 includes a main body 5a that is a hollow cup, a ring-shaped locking member 5b, and a support film 5c that transmits X-rays. More specifically, a circular support film 5c having a diameter slightly larger than the outer diameter of the main body 5a is placed so as to cover the opening of the main body 5a, and the locking member 5b is fitted to the outside of the main body 5a from above. Thus, the periphery of the support film 5c is sandwiched between the locking member 5b and the main body 5a. A film made of polyester, polypropylene, polyimide, or the like can be used for the support film 5c.

  Then, the molded sample 3 is placed on the support film 5c of the sample holder 5, the primary X-ray 6 is irradiated on the upper surface of the molded sample 1B, and the intensity of the generated fluorescent X-ray 7 is increased. taking measurement. Since the upper surface of the molded sample 1B is not covered with a film or the like and the sample 1B is exposed, measurement can be performed without attenuating the fluorescent X-rays 7 from the light elements. In addition, below the molded sample 1B, there are only the polymer film 2 and the support film 5c that transmit X-rays, and the space below is a cavity, so that the background during fluorescent X-ray analysis is also sufficiently reduced. The Further, after the fluorescent X-ray analysis, the molded sample 1B can be easily recovered simply by peeling from the polymer film 2 and can be used for another chemical analysis.

It is a figure which shows the powder sample and polymer film before pressurization in the powder sample shaping | molding method of one Embodiment of this invention. It is a figure which shows the sample and polymer film in pressurization in the same method. It is a figure which shows the shaping | molding sample which consists of the sample after pressure molding and a polymer film in the same method. It is a figure which shows the state which has provided the shaping | molding sample obtained by the same method to a fluorescent X ray analysis.

Explanation of symbols

1A Powder sample 1B Sample 2 after pressure molding 2 Polymer film

Claims (2)

  A powder sample molding method in which a minute amount of a powder sample is pressure-molded in the thickness direction of the polymer film together with a single polymer film so as to be subjected to fluorescent X-ray analysis. In claim 1,
The powder sample shaping | molding method whose said polymer film consists of polyester, a polypropylene, or a polyimide, and whose thickness is 10 micrometers or less.

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