JPH0257951A - Standard specimen for fluorescent x rays and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the scattering of a standard specimen when X rays are emitted and to perform measurement whose absolute value is stabilized for a long time by attaching fine powders of one or two or more kinds of metal oxides having a specified amount on a filter, and covering the powder with a macromolecular thin film. CONSTITUTION:Metal oxides reagents shown in the Table are finely crushed. Specified amounts of the reagents are measured. The reagents are put into a measuring flask. Pure water is added, and the level is aligned with a marked line. The powders in the pure water are uniformly dispersed for 15-20min by using an ultrasonic wave cleaner, and a standard liquid is obtained. Then several-ml pure water is added on a specimen filter which is set on a filter device. The specified amount of the standard liquid which is prepared beforehand is accurately dispersed and dropped. After about 1min, filtering operation is performed. A macromolecular compound is blown on the capturing surface of the obtained metal oxide, and a protecting film is provided. The film is dried, and the standard specimen for fluorescent X rays is obtained. Since the metal oxide is used in the same pattern as an actual specimen, an analyzer can be calibrated accurately. The absolute value of the minute metal component in the actual specimen can thus be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a standard sample for fluorescent X-rays whose quality is stable over a long period of time, and a method for producing the same.

(Prior Art) Fluorescence X-ray analysis has been known as one of the methods for analyzing and quantifying trace metal components in water.

In this method, trace metal components are collected on a filter and analyzed and quantified using a fluorescence A standard specimen of this morphology is required.

Conventionally, such standard samples include DDTC standard samples in which precipitates are collected on a filter and dried, and glass bead standard samples in which metal oxides are mixed with a fluxing agent such as sodium borate and melted at high temperatures. etc. are known.

(Problem to be Solved by the Invention) However, the former DDTC standard sample has disadvantages in that it is subject to large scattering due to mechanical impact during X-ray irradiation, changes over time, and is a precipitate that differs in form from the actual sample. was there. On the other hand, the latter glass bead standard sample is
Not only was it difficult to create, the resulting product was easily broken, and like the former, it had the disadvantage of differing in form from the actual sample. Furthermore, each of these standard samples had the disadvantage that only relative values could be measured.

The present invention has been made in order to eliminate these drawbacks of conventional standard samples, and it eliminates the scattering of the standard sample during X-ray irradiation, and also makes it possible to measure absolute values and obtain stable measurement values over a long period of time. The purpose is to provide a standard sample for fluorescent X-rays that can be used.

[Structure of the Invention] (Means for Solving the Problems) That is, the standard sample for fluorescent X-rays of the present invention is prepared by depositing a predetermined amount of one or more metal oxide fine powders on a filter, It is characterized by being coated with a thin polymer film, and its manufacturing method involves adding a predetermined amount of 1f to pure water.
Prepare a standard solution by uniformly dispersing I or two or more types of metal oxide fine powder, and filter this standard solution using a sample filter to uniformly distribute a certain amount of metal oxide on the filter. After collection, a polymer solution is deposited on the collection surface of the metal oxide fine powder of the filter and dried.

As the metal oxide to be dispersed in pure water, a reagent of the highest purity is used, and this is thoroughly pulverized in advance in an agate mortar or an electric pulverizer having an agate pulverizer. The finely ground metal oxide is added to pure water, and ultrasonic waves are applied for about 15 to 20 minutes using an ultrasonic cleaner to uniformly disperse it in the pure water.

In addition, by dropping a certain amount of the standard solution obtained in this way onto the sample filter and performing the filtration operation after about 1 minute, the metal oxide can be uniformly dispersed on the filter. be captured.

The protective coating to be applied on the collection surface is preferably a sprayed polymer film or a plastic film pouch.

(Function) In the fluorescent X-ray standard sample of the present invention configured as described above, metal oxides are uniformly dispersed in water by the ultrasonic cleaner in the same manner as the actual sample to be analyzed, and further Since the sample is collected uniformly on the filter in the same manner as in the above, the actual sample and the standard sample can have the same form. Furthermore, since a protective coating is provided on the collection surface of the filter, it is possible to prevent the standard sample from scattering.

Further, according to the method of the present invention, such a standard sample can be easily produced.

(Example) Examples of the present invention will be described below.

Metal oxide reagent (Fe; + 03 , CoO, CuO,
Nl01ZnO's Cr203, MnO°2) were sufficiently pulverized in an agate mortar, and a certain amount of the pulverized metal oxide was accurately weighed using a semi-microbalance. The following table shows the purity of each reagent used.

(Margin below) (Note): Book bound by Mitsuwa Kagaku Co., Ltd.*: Manufactured by Kanto Kagaku Co., Ltd.* These weighed metal oxide fine powders were placed in a volumetric flask, and pure water was added thereto to match the marked line. Then, these metal oxide fine powders in pure water were uniformly dispersed for 15 to 20 minutes using an ultrasonic cleaner to obtain a standard solution. At this time, during dispersion using an ultrasonic cleaner, it is preferable to cool the liquid using ice or the like so that the temperature of the liquid does not rise.

Next, place it on the sample filter that has been set on the filter in advance.
Add pure water of number 1. Then, a certain amount of the previously prepared standard solution was accurately dispersed and dropped into the solution using, for example, an Eppendorf bivet. The condition was maintained for about 1 minute, and then a filtration operation was performed. A protective film was provided on the metal oxide collecting surface thus obtained by spraying a polymer compound, and then dried to obtain a standard sample for fluorescent X-rays of the present invention.

The thus obtained fluorescent X-ray marker sample endured long-term use without any scattering due to mechanical impact during X-ray irradiation. Further, according to this example, it was possible to determine n1 the absolute value of a trace metal component contained in an actual sample, as shown by the calibration curve in the drawing, taking iron as an example.

[Effects of the Invention] As explained above, the standard sample for fluorescent X-rays of the present invention has the following properties:
Since the metal oxide is used in a form similar to that of the actual sample, the X-ray fluorescence spectrometer can be calibrated more accurately. Therefore, according to the present invention, it is possible to measure the absolute value of trace metal components contained in an actual sample. Furthermore, since a protective film made of a material that does not affect measured values is provided on the surface of the standard sample, stable quality can be maintained over a long period of time. Further, according to the method of the present invention, such a standard sample can be easily manufactured.

[Brief explanation of the drawing]

The figure is a calibration curve for iron obtained using one embodiment of the present invention. Applicant Japan Atomic Energy Corporation

Claims (2)

[Claims] (1) A standard sample for fluorescent X-rays, characterized in that a predetermined amount of one or more metal oxide fine powders is deposited on a filter, and the filter is coated with a thin polymer film. (2) Prepare a standard solution by uniformly dispersing a predetermined amount of one or more metal oxide fine powders in pure water, and filter this standard solution using a sample filter to obtain a fixed amount. A standard sample for fluorescence Production method.