JP6863069B2 - X-ray fluorescence analyzer and sample container used for it - Google Patents

Description

The present invention relates to an X-ray fluorescence analyzer for measuring elemental components and their contents in a powder sample or a lightweight material sample, and a sample container for the X-ray fluorescence analyzer.

The X-ray fluorescence analyzer excites the characteristic X-rays of the element to be analyzed in the analysis sample by using the primary X-rays emitted by the X-ray tube, and adopts the method of energy dispersion or wavelength dispersion. It is an elemental analyzer that detects X-rays. The structure of an X-ray fluorescence analyzer is shown in FIG. 1 when analyzing a powder sample or a lightweight material (eg, food or biomaterial) sample. The X-ray fluorescence analyzer 10 includes a sample cup 11 for storing a sample, an X-ray generator 12, and an X-ray detector 13. The sample cup 11 includes a sample lid 110, a cylindrical side wall 111, and a Mylar film 112 fixed below the cylindrical side wall 111 with a jig 113. The X-ray detector may be a wavelength dispersive detection system based on an analyzer crystal or an energy dispersive detection system based on a solid-state detector.

The X-ray tube (sometimes adopting an X-ray filter and a collimator) in the X-ray generator 12 emits primary X-rays a1 and a2 and the like. Primary X-rays penetrate the Mylar film 112 and irradiate (excite) a sample (not shown) in the sample cup 11, and the irradiated sample emits X-ray fluorescence and some fluorescence (shown in FIG. 1). Y1 and Y2, etc.) are received by the X-ray detection device 13 to acquire an X-ray fluorescence spectrum. Qualitative and quantitative analysis is performed on the elements of the sample by X-ray fluorescence spectrum.

When the sample is a powder or a lightweight material (food, biomaterial, etc.), the primary X-ray excites the sample, further penetrates the outside of the sample cup 11, and finally the outer shell of the X-ray fluorescence analyzer (the outer shell of the X-ray fluorescence analyzer. Since it is absorbed in (not shown), it cannot be reused to excite the sample. As described above, since the total amount of fluorescent X-rays generated is small, the sensitivity of the X-ray fluorescence analyzer is low.

Utility Model Registration No. 2584946

In order to solve the above problem, generally, the power of the X-ray tube is improved, the detection area (energy dispersive type) of the X-ray detector 13 is increased, or the optical path of the X-ray is shortened as much as possible. Increasing the power of the X-ray tube to increase the detection area (energy dispersive type) of the X-ray detection device 13 will increase the manufacturing cost of the entire X-ray fluorescence analyzer, and if a high-power X-ray tube is used, , Further increase the volume of the X-ray fluorescence analyzer. The present invention provides a new method for improving the sensitivity of X-ray fluorescence analysis when analyzing a powder sample or a biological sample by changing the structure of the sample container.

The present invention provides a sample container for an X-ray fluorescence analyzer, wherein the sample container consists of a container lid, a container side wall and a container bottom, and is used for storing a sample, of which the container lid and the container side wall At least one of them is fitted with a polycrystalline powder material such as lithium fluoride. Due to the diffractive action of the polycrystalline material, some X-rays penetrating the sample and vessel wall return to the sample to re-excitate the X-ray fluorescence, thus increasing the total amount of X-ray fluorescence of the sample and increasing the sensitivity of the device. Also improve.

The container lid has an inner surface that can contact the sample and an outer surface that can contact the outside, and the container lid is made of a material in which a portion between the inner surface and the outer surface contains the polycrystalline powder. The container side wall has an inner surface that can contact the sample and an outer surface that can contact the outside, and the container side wall is made of a material in which a portion between the inner surface and the outer surface contains the polycrystalline powder. Become. In this way, the lithium fluoride polycrystalline powder contaminates the sample in the sample cup 21 and prevents the outside from coming into contact with the lithium fluoride polycrystalline powder.

The sample container is a cylindrical sample cup, and the side wall of the container is a cylindrical side wall.

The bottom of the container is a Mylar film fixed below the cylindrical side wall with a jig.

The X-ray fluorescence analyzer includes an X-ray generator and an X-ray detector, and the X-ray generator incidents X-rays on the sample in the sample container via the Mylar film and causes the sample to undergo X-ray fluorescence. Upon emission, the X-ray detector detects a portion of the X-ray fluorescence.

The present invention further provides an X-ray fluorescence analyzer, which includes an X-ray generator, an X-ray detector, and the sample container, wherein the X-ray generator transmits X-rays through the Mylar film and the sample container. The X-ray detector detects a part of the fluorescence by incident on the sample in the above and causing the sample to emit fluorescence.

Due to the diffracting action of the polycrystalline powder fitted in the sample cup, the X-rays emitted from the X-ray generator repeatedly irradiate (excit) the sample in the sample cup to enhance the fluorescence signal from the sample. Therefore, the X-ray detector 23 can detect the enhanced fluorescence, thus improving the sensitivity of the X-ray fluorescence analyzer 20.

It is a partial structure schematic diagram of the conventional X-ray fluorescence analyzer. It is a partial structure schematic diagram of the X-ray fluorescence analyzer according to this invention.

Hereinafter, examples of the present invention will be specifically described by combining the drawings.

FIG. 2 is a schematic partial structure diagram of the X-ray fluorescence analyzer according to the present invention. As shown in FIG. 2, the X-ray fluorescence analyzer 20 includes a sample container 21, an X-ray generator 22, and an X-ray detector 23.

The sample container 21 includes a container lid 210, a container side wall 211, and a container bottom 212, and is used for storing a sample. The sample container 21 is a cylindrical sample cup (hereinafter referred to as a sample cup 21), and the container side wall 211 is a cylindrical side wall (hereinafter referred to as a side wall 211).

The container bottom 212 is a Mylar film (hereinafter referred to as Mylar film 212) fixed below the side wall 211 by a jig 213. The X-ray generator 22 incidents X-rays (for example, a1 and a2) on the sample in the sample cup 21 via the Mylar film 212 to emit fluorescence to the sample, and the X-ray detector 23 emits a part of the fluorescence (for example, d1). , D2) is detected. At least one of the container lid 210 and the side wall 211 is made of a material containing polycrystalline powder. In this embodiment, for example, as shown in FIG. 2, both the container lid 210 and the side wall 211 are made of a material containing polycrystalline powder. The polycrystalline powder can be lithium fluoride.

The container lid 210 has an inner surface 210a that can contact the sample in the sample cup 21 and an outer surface 210b that can contact the outside, and the container lid 210 has a portion between the inner surface 210a and the outer surface 210b, for example, lithium fluoride. Consists of materials containing. The side wall 211 has an inner surface 211a that can contact the sample in the sample cup 21 and an outer surface 211b that can contact the outside, and the side wall 211 has a portion between the inner surface 211a and the outer surface 211b, for example, a lithium fluoride polycrystal. Consists of materials containing powder. In this way, the lithium fluoride polycrystalline powder contaminates the sample in the sample cup 21 and prevents the outside from coming into contact with the lithium fluoride polycrystalline powder.

The sidewalls of the sample cup in the prior art are generally made by injection molding high density polyethylene or other material. In the present invention, for example, the lithium fluoride polycrystalline powder is fitted between the inner side surface 211a and the outer side surface 211b of the side wall 211 of the sample cup 21, and between the inner surface 210a and the outer surface 210b of the container lid 210. The lithium fluoride polycrystalline powder is inlaid and is shown by the dots in FIG.

As shown in FIG. 2, the X-ray generator 22 incidents X-rays a1 on the sample in the sample cup 21 via the Mylar film 212, excites the sample, and irradiates the lithium fluoride polycrystalline powder on the side wall 211. .. Due to the diffracting action of the lithium fluoride polycrystalline powder, it becomes diffracted light, for example, b1 and b2. The diffracted light b1 is irradiated on the lithium fluoride polycrystalline powder in the container lid 210, and due to the diffracting action of the lithium fluoride polycrystalline powder, it becomes the diffracted light c1. At the same time, the diffracted light b2 is further irradiated to the lithium fluoride polycrystalline powder on the side wall 211, and due to the diffracting action of the lithium fluoride polycrystalline powder, it becomes further diffracted light c2.

In the diffraction process, the diffracted lights b1, b2 and c1 and c2 are repeatedly irradiated to the sample in the sample cup 21, respectively, so that the X-ray a1 irradiates the sample with the paths a1, b1, c1 and a1, b2, respectively. It contains c2 and is finally penetrated out of the sample cup 21. Since the diffracted X-rays can be reused, the sample in the sample cup 21 is repeatedly irradiated, that is, the sample is repeatedly excited, so that the repeatedly excited sample is an enhanced X-ray fluorescence d1. , D2 etc. (fluorescent signal). In this way, the X-ray detection device 23 detects the enhanced fluorescence d1, d2, etc., and improves the sensitivity of the X-ray fluorescence analyzer 20.

Further, the X-rays a1, a2, diffracted light b1, b2, c1, c2 and fluorescence d1 and d2 shown in FIG. 2 are merely examples and are not comprehensive.

In this embodiment, the X-ray detector 23 may be a wavelength dispersive detector based on an analyzer crystal or an energy dispersive detector based on a solids detector.

Although specific examples of the present invention have been described, these examples will be described only by means of examples and do not limit the scope of the present invention. In fact, the innovative methods described herein can be implemented in a variety of other forms; and without departing from the spirit of the invention, various abbreviations for the methods and systems described herein. , Substitution and change. The appended claims and their equivalents are intended to include various forms or modifications in the scope and spirit of the invention.

Claims (7)

A sample container for a line fluorescence analyzer
The sample container consists of a container lid, a container side wall and a container bottom, and is used for storing a sample.
A sample container characterized in that a polycrystalline powder material is fitted in at least one of the container lid and the container side wall. The container lid has an inner surface that can contact the sample and an outer surface that can contact the outside, and the container lid is fitted with the polycrystalline powder material in a portion between the inner surface and the outer surface.
The container side wall has an inner surface that can contact the sample and an outer surface that can contact the outside, and the container side wall is fitted with the polycrystalline powder material in a portion between the inner side surface and the outer surface. The sample container according to claim 1. The sample container according to claim 2, wherein the polycrystalline powder material is a lithium fluoride polycrystalline powder. The sample container according to claim 3, wherein the sample container is a cylindrical sample cup, and the side wall of the container is a cylindrical side wall. The sample container according to claim 4, wherein the bottom of the container is a Mylar film fixed below the cylindrical side wall with a jig. The X-ray fluorescence analyzer includes an X-ray generator and an X-ray detector, and the X-ray generator causes X-rays to enter the sample in the sample container via the Mylar film and emit fluorescence to the sample. The sample container according to claim 5 , wherein the X-ray detection device detects a part of the fluorescence. The X-ray generator, the X-ray detector, and the sample container according to claim 5 are included.
The X-ray generator is characterized in that X-rays are incident on the sample in the sample container via the Mylar film to emit fluorescence to the sample, and the X-ray detector detects a part of the fluorescence. X-ray fluorescence analyzer.

Images