JP2841258B2 - X-ray fluorescence qualitative analysis method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray fluorescence qualitative analysis method, and more particularly to an X-ray fluorescence qualitative analysis method capable of performing qualitative analysis with high accuracy on a measurement sample containing a plurality of types of elements. It is.

[0002]

2. Description of the Related Art Generally, in a fluorescent X-ray analyzer, a measurement sample (hereinafter referred to as a sample) 2 to be measured is irradiated with X-rays from an X-ray generator 1 and emitted from the sample 2 as shown in FIG. The detected fluorescent X-rays 3 are detected by the detector 4 and the data collection device 41 obtains spectrum data as shown in FIG.

At this time, since the energy value of the generated fluorescent X-ray 3 is determined for each element contained in the sample 2, this spectrum data has a peak at an energy position corresponding to the element contained in the sample 2. Having. The element contained in the sample 2 can be specified from the position of this peak.

[0004] In this conventional kind qualitative analysis method, the order checked for peak energy positions of the fluorescent X-ray of each element, has been to determine whether the element is decided importance in high probability order .

[0005]

However, in sample 2,
As shown in FIG. 9, a spectrum 5 having a peak position a and having a peak position a generated from a certain element and having another peak 6 having a peak position b are spectrum data obtained from a sample 2 composed of a plurality of types of elements. And the spectrum 5 may not be recognized as having an independent peak position a, resulting in an erroneous determination that the element is not contained, and it is difficult to perform qualitative analysis with high accuracy.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an X-ray qualitative fluorescent analysis method capable of reliably measuring an element from a sample composed of a plurality of types of elements.

[0007]

In order to achieve the above-mentioned object, the present invention provides a method for irradiating a measurement sample with X-rays emitted from an X-ray generator and converting the fluorescent X-rays emitted from the measurement sample. When performing a qualitative analysis of the elements contained in the measurement sample by detecting the signal with a detector and reading the signal as spectral data via a signal processing unit ,
To obtain spectral data from the fluorescent X-rays emitted from this the measurement sample, each element that has been predetermined and their determining a data peak occurrence position generated, the occurrence of the peak position obtained from the data of comparing the reference peak position, the result of this comparison, a step of quantifying the degree of coincidence between the reference peak position and the peak occurrence position, a result of the numerical values, or values that values obtained numerical Is determined, the element is determined to be contained in the measurement sample, on the other hand, if the obtained numerical value is less than a certain value,
The relevant sample the elements Ri Do and a step of performing judgment that does not include further the digitizing is, y = sigma {[(A × h-ΔE) × I ] / (A × h) ｝ / ΣI (1) (where A × h−ΔE = 0 when A × h−ΔE <0 in equation (1) ) where y: numerical value of a certain element A: coefficient h: height ΔE of the measured peak: the peak occurrence position (measured peak position), displacement of the reference peak position that occurs from a certain element (peak position) I: be conducted by the formula represented by the weight corresponding to the probability of occurrence of the peak X-ray fluorescence qualitative analysis method.

In the present invention, each step itself uses a known method, but by combining these steps, as shown in FIG. 9, a peak position a generated from a certain element and having a high degree of importance is obtained. The spectrum 5 overlaps the other spectrum 6 having the peak position b, and the spectrum 5
May not be recognized as having an independent peak position a, and it is possible to avoid a conventional situation that results in an erroneous determination that the element is not included.

In the present invention, the value of an existing data table is usually stored in, for example, the computer 14 shown in FIG. 1 as the reference peak position of each element used for comparison with the peak generation position obtained from the spectrum data. Let it. It is preferable to determine in advance by the following method. Since the energy value of the fluorescent X-ray generated for each element is determined, the peak position formed at the energy position corresponding to each element is used for each element as a reference peak position. Remember. At this time, as a method of obtaining the reference peak position,

First, for one element, for example, spectrum data is created by a simulation calculation in consideration of the resolution of a detector. Further, this spectrum data is obtained for all the elements. That is, the determination is performed for all the elements included in the determination of the qualitative analysis, and, for example, the spectrum data of the different elements is sequentially obtained following the data of the spectrum of the element.

Then, based on the plurality of obtained spectra, reference peak positions L, M, N... Corresponding to the energy positions of fluorescent X-rays generated from a certain element (FIGS. 2 and 5).
(See Reference).

[0012] reference peak position L generated for each of these previously the elements, M, and N · · ·, for example, our Ku and stored in the computer 14 shown in FIG.

In the present invention, in FIG. 1, spectrum data is obtained from the fluorescent X-rays 10 emitted from the measurement sample 9, and the peak generation position is determined from the data. As shown in FIG.
The data obtained by the measurement sample 9 of, for example,
Peak generation positions A to H are obtained by signal processing means including the multi-channel analyzer 13 shown in FIG.

Next, in the present invention, the peak generation position obtained from the data is compared with a predetermined reference peak position of each element, and as a result of the comparison, the peak generation position and the reference peak position are compared. Quantify the degree of coincidence with the position. This numerical expression is given by the above expression (1). This is because, as shown in FIGS. 2 to 5, the fluorescent X-ray 10 emitted from the measurement sample 9 is located at a position that matches the energy position (reference peak position) of the fluorescent X-ray generated by the element used for comparison .
Gave the highest value if the peak of the spectral data obtained Ri, if the peak of the spectral data at a position out of the energy position of the fluorescent X-ray element occurs used for comparison (reference peak position), its disengaged degree ( Δ
Numerical values are given according to E) and the peak height h. This numerical value is calculated so as to become smaller as the peak position deviates.

That is, in FIG. 2, for example, when a peak generation position D is compared with a predetermined reference peak position M of an element to be compared to determine a numerical value,
Deviation Δ between peak generation position (measurement peak position) D and reference peak position (peak position) M of a certain element used for comparison
E, that is, how far the reference peak position (peak position) is away from the peak occurrence position (measurement peak position), is expressed as a numerical value. In FIG. 2, refer to FIGS. 3 and 4. Then, if it is out of a certain range W, w (W> w), it is converted to a numerical value of 0. Moreover, as shown in FIG. 3, this range corresponds to the spectrum data 1 from the measurement sample 9.
When the occurrence peak of 9a is high, the range W is widened,
On the other hand, as shown in FIG. 4, when the generation peak of the spectrum data 19b from the measurement sample 9 is low, the range w is narrow.

Subsequently, there are several types of energy of fluorescent X-rays generated from one element, and this calculation is performed for each energy position that may be detected as a generation peak. [(A × h−Δ)]
E) × I]. This is divided by the value (Ah) when the energy positions match, and the values obtained by this calculation are summed up <<<<
{[(A × h−ΔE) × I]} / (A × h)}, and a value y obtained by standardizing {[(A × h−ΔE) × I] / (A × h)} << y = Σ ｛[(A × h-ΔE)
× I] / (A × h)｝ / ΣI (1) >> .

In short, in the above equation (1), a certain element is quantified according to the degree of deviation of the peak and the height of the peak.

When the numerical value obtained by this method becomes a numerical value equal to or more than a certain value, it is determined that the element is contained in the measurement sample 9, while the numerical value obtained is a certain value. When the numerical value becomes less than the value, it is determined that the element is not included in the measurement sample 9. When it is determined that the element is contained in the measurement sample 9, the element is added to the qualitative analysis result. By performing this process for all the elements included in the determination of the qualitative analysis, the qualitative analysis can be performed with high accuracy even in the case of a measurement sample containing a plurality of types of elements. In addition, the element is contained,
It is possible to determine not only the determination that the element is not included but also the possibility that the element is included. Further, it is possible to make the criterion variable according to the measurement sample system to be measured.

In this way, the peak generation position D when a certain measurement sample 9 is measured is compared with a predetermined reference peak position M of each element. Since the degree of coincidence with M is quantified by the above equation (1), it is determined whether or not the measurement sample contains a plurality of types of elements even if it is contained. As a result, qualitative analysis can be performed with high accuracy. In particular, as shown in FIG. 9, a high degree of importance of a certain element, spectral 5 peak position b having a peak position a
May overlap with another spectrum 6 having the following, and may not be able to recognize the spectrum 5 as having an independent peak position a, resulting in an erroneous determination that the element is not contained in the measurement sample. Can be avoided.

Even when the resolution changes due to replacement of the detector, etc., the resolution is known in advance according to the detector. (A) can be set, and qualitative analysis can be performed with high accuracy.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the X-ray fluorescence qualitative analysis method according to the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited thereby. In FIG. 1, 7 is an X-ray generator, 9 is a sample to be measured, 11 is a detector, 12 is an A / D converter, 13 is a multi-channel analyzer, and 14 is a computer.

An X-ray 8 emitted from an X-ray generator 7 is applied to a measurement sample 9 and a fluorescent X-ray emitted from the sample 9 is emitted.
The line 10 is detected by the detector 11, and the signal is read as spectral data by the computer 14 via the A / D converter 12 and the multi-channel analyzer 13. The computer 14 performs a qualitative analysis based on the obtained spectrum data. In this computer 14, peak positions L, M, N... Generated in advance for each element are stored in advance (see FIG. 5).
Is stored.

FIG. 6 shows a procedure for performing a qualitative analysis process on the measurement sample 9. In FIG. 6, the qualitative analysis process is started in step 101, and the fluorescence X emitted from the measurement sample 9 is obtained.
Spectral data is obtained from line 10 (step 102).
Then, peak occurrence positions A to F are obtained from the data (see step 103). Then, the reference peak positions L, M, N... Predetermined for each element are compared with the peak generation positions A to F, G, and H. Further, the peak generation positions A to F, G, and H and the reference peak positions L, M, N
The degree of coincidence between ..., digitizing with such as the above mentioned (1) (see step 104).

Next, as a result of the digitization, when the obtained numerical value becomes a numerical value equal to or more than a certain value, it is determined that the element is contained in the measurement sample 9, while the obtained numerical value is a certain value. When the value is less than the value, it is determined that the element is not included in the measurement sample 9 (see step 105). When it is determined that the element is included in the measurement sample 9, the element is qualitatively determined. It is added to the analysis result (see step 106). Then, this process is performed for all elements included in the determination of the qualitative analysis (see step 107), and the qualitative analysis process ends (see step 108). Thereby, even in the case of a measurement sample containing a plurality of types of elements, qualitative analysis can be performed with high accuracy. In particular, as shown in FIG. 9, other spectral 6 having spectral 5 a peak position b having high importance of a certain element, the peak positions a
To prevent the spectrum 5 from being recognized as having an independent peak position a, which may result in an erroneous determination that the element is not contained in the measurement sample. it can. Further, it is possible to determine not only the determination that the element is included but also the absence of the element, but also the degree of the possibility that the element is included. Further, it is possible to make the criterion variable according to the measurement sample system to be measured.

[0025]

As described above, the fluorescent X of the present invention is used.
Above line qualitative analysis method, and the peak occurrence position when a measurement sample was measured with, compares the reference peak position of each element previously determined, moreover, the degree of coincidence between the peak occurrence position and the reference peak position Numerical values are obtained by using the above equation (1) , and it is determined whether or not a certain element is contained in the measurement sample based on the numerical value. In this case, the highest value is given if there is a peak of spectral data obtained from the fluorescent X-ray emitted from the measurement sample at a position corresponding to the energy position (reference peak position) of the fluorescent X-ray generated by the element used for comparison, If there is a peak of the spectrum data at a position deviating from the energy position (reference peak position) of the fluorescent X-ray generated by the element used for comparison, a numerical value is given according to the degree of deviation (ΔE) and the peak height h. A calculation is made. Therefore, even in the case of a measurement sample containing a plurality of types of elements, there is an effect that qualitative analysis can be accurately performed. Even when the resolution changes due to replacement of the detector, etc., qualitative analysis can be performed with high accuracy by setting the coefficients of the numerical expression according to the resolution.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing one embodiment of an analyzer used in a fluorescent X-ray qualitative analysis method according to the present invention.

FIG. 2 is an explanatory diagram including a step of performing digitization in the embodiment.

FIG. 3 is an explanatory diagram including a step of performing digitization in the same embodiment.

FIG. 4 is an explanatory diagram including a step of performing digitization in the same embodiment.

FIG. 5 is a diagram showing spectrum data obtained from a measurement sample containing a plurality of types of elements in the above example.

FIG. 6 is a flowchart in the embodiment.

FIG. 7 is a configuration explanatory view showing a conventional example.

FIG. 8 is a diagram showing a peak generation position of a measurement sample in a conventional example.

FIG. 9 is a diagram showing an analysis method in a conventional example.

[Explanation of symbols]

7 X-ray generator, 8 X-ray, 9 sample, 10 fluorescent X-ray, 11 detector, 12 A / D converter, 13 multi-channel analyzer, 14 computer, 19
a, 19b: spectrum, L, M, N: reference peak position, A to H: peak generation position.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 23/223

Claims (1)

(57) [Claims] An X-ray emitted from an X-ray generator is irradiated on a measurement sample, fluorescent X-rays emitted from the measurement sample are detected by a detector, and the signal is read as spectrum data via a signal processing means. the time of measurement performed a qualitative analysis of elements contained in the sample, to obtain spectral data from the fluorescent X-rays emitted from this the sample by,
Determining a peak occurrence position occurring in the data; and determining the peak occurrence position obtained from the data in advance.
Comparing the determined reference peak positions of the respective elements, and as a result of this comparison, digitizing the degree of coincidence between the peak occurrence position and the reference peak position, and a numerical value obtained as a result of the digitization If the value is equal to or greater than a certain value, it is determined that the element is contained in the measurement sample.On the other hand, if the obtained value is less than a certain value, the element is included in the measurement sample. And the process of determining that
Further, the above-mentioned numerical value is expressed as follows: y = {[(A × h−ΔE) × I] / (A × h)} / ΣI (1) (where A × h− When ΔE <0, it is defined as A × h−ΔE = 0) where y: Numerical value of a certain element A: Coefficient h: Height of measured peak ΔE: Peak generation position (measured peak position) displacement of the reference peak position that occurs (peak position) I: X-ray fluorescence qualitative analysis how to characterized by being performed by the formula represented by the weight corresponding to the probability of occurrence of the peak.