JP2002071590A - X-ray fluorescence analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent X-ray analyzer that can sufficiently analyze a sample having a wide compositional range by expanding an introduced internal standard method. SOLUTION: This fluorescent X-ray analyzer is provided with a calculating means 16 which performs analysis by an FP method introducing the internal standard method in which a fluorescent X ray from an internal standard element is used as an internal standard line for a designated component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the intensity of fluorescent X-rays
The present invention relates to a fluorescent X-ray analyzer using a broadly defined internal standard method that uses the ratio to the intensity of a line or background.

[0002]

2. Description of the Related Art Conventionally, in X-ray fluorescence analysis, to correct the influence of absorption and excitation by coexisting elements, the intensity of X-ray fluorescence (analysis line) from a component to be analyzed and the addition of a predetermined amount to a sample have been known. There is an internal standard method using the ratio of the intensity of the fluorescent X-rays from the internal standard element and the background (internal standard line), which has been introduced into the calibration curve method. Specifically, using a standard sample, a calibration curve that is a correlation between the measured intensity ratio of the analysis line and the internal standard line and the content of the analysis component is obtained in advance.
A calibration curve is applied to the measured intensity ratio for the sample to be analyzed to calculate the content of the analysis component.

Here, the calibration curve method includes a so-called semi-fundamental parameter method (hereinafter, referred to as SFP method). In the SFP method, the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples whose composition is assumed is calculated, and a theoretical matrix correction coefficient for absorption and excitation of fluorescent X-rays is calculated based on the theoretical intensity. The calibration curve corrected using the theoretical matrix correction coefficient is used. For a standard calibration curve method for experimentally obtaining a matrix correction coefficient using a standard sample, an internal standard method using various internal standard lines has been introduced. However, for the SFP method, the characteristic X-ray (Refer to claim 1 of Japanese Patent No. 3059403).

[0004] On the other hand, as contrasted with the calibration curve method,
Fundamental parameter method (hereinafter referred to as FP method)
There is. In the FP method, the converted intensity to the theoretical intensity scale based on the measured intensity of the fluorescent X-ray and the theoretical intensity of the fluorescent X-ray calculated assuming the content of each component in the sample (composition of the sample) for each corresponding component In contrast to the above, the content of each component is calculated by successively approximating and correcting the content of each component so that both intensities match, and the content of each component is calculated. Can be corrected. Therefore,
It has been considered unnecessary to introduce an internal standard method into the FP method.

[0005]

However, the SF introduced the internal standard method using the scattered X-ray characteristic X-rays of the X-ray tube described above.
In the P method, when the sample contains an element having an absorption edge at a wavelength between the analysis ray and the scattered ray, the theoretical matrix correction coefficient of the element becomes too large or the sample is thin. In some cases, a sufficiently accurate analysis cannot be performed depending on the sample because the thickness is affected.

In addition, as described above, in the FP method, in order to calculate the theoretical intensity of each fluorescent X-ray from the content of all the components of the sample, for example, in a mineral powder sample, Fe _{2 to be} analyzed is used.
The content of heavy element components such as O ₃ is affected by the content of light element components such as SiO ₂ , Al ₂ O ₃ , and MgO, which are prone to errors due to the mineral effect and the grain size effect. The analysis is not accurate enough.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides an X-ray fluorescence spectrometer capable of expanding the introduction of an internal standard method and performing sufficiently accurate analysis of a sample having a wide composition range. The purpose is to:

[0008]

In order to achieve the above object, an X-ray fluorescence analyzer according to claim 1 comprises an X-ray tube for irradiating a sample with primary X-rays, and a secondary X-ray generated from the sample. Detecting means for measuring the intensity of the X-rays, the intensity converted to a theoretical intensity scale based on the measured intensity of the fluorescent X-rays measured by the detecting means,
Fluorescence X calculated assuming the content of each component in the sample
Computing means for comparing the theoretical intensity of the line for each corresponding component, sequentially and approximately correcting and calculating the assumed content of each component such that the two intensities match, and calculating the content of each component. And That is, it is a fluorescent X-ray analyzer that performs analysis by the FP method. Here, for the specified component, the calculating means calculates the fluorescent X-ray intensity from the component and the fluorescence X from the internal standard element added to the sample in a predetermined amount.
The converted intensity ratio to the theoretical intensity scale based on the measured intensity ratio with the measured intensity of the line, the theory of the theoretical intensity of the fluorescent X-ray from the specified component and the theoretical intensity of the fluorescent X-ray from the internal standard element Compare whether the intensity ratios match.

In the apparatus according to the first aspect of the present invention, the designated component is analyzed by the FP method in which the internal standard method using fluorescent X-rays from the internal standard element as the internal standard line is used. The effect of the internal standard method is such that the error of the content of the light element component due to the mineral effect and the particle size effect is hardly affected by the content of the specified heavy element component to be analyzed. Moreover, due to changes in the content of heavy element components other than the analysis components,
Even if the intensity ratio of the analysis component changes, the effect of the FP method that appropriate theoretical calculation including the change can be maintained. Therefore, a sufficiently accurate analysis can be performed on a sample having a wide composition range.

[0010] The X-ray fluorescence analyzer according to the second aspect is also provided with a calculation means and the like, and performs the analysis by the FP method. Here, the calculating means is:
For the designated component, the converted intensity ratio to the theoretical intensity scale based on the measured intensity ratio of the measured intensity of the fluorescent X-ray from the component and the measured intensity of the background of the fluorescent X-ray, and the designated component The theoretical intensity ratio between the theoretical intensity of the fluorescent X-rays from the subject and the theoretical intensity of the background of the fluorescent X-rays is compared with each other.

In the apparatus according to the second aspect of the present invention, the designated component is analyzed by the FP method in which the background of the fluorescent X-ray from the component is used as the internal standard line, and the internal standard line used is used. Although the type is different, the same operation and effect as those of the device of claim 1 can be obtained. Also, for example, in the analysis of Sr etc. in rocks, unlike the normal calibration curve method which introduced the internal standard method using the background or characteristic X-ray scattered X-ray scattered radiation as the internal standard line described in the prior art. Even if the composition of the sample greatly changes, it can be appropriately dealt with by theoretical calculation. Therefore, sufficiently accurate analysis can be performed on a sample having a wide composition range.

[0013] The X-ray fluorescence analyzer according to the third aspect is also provided with a calculating means or the like and performs the analysis by the FP method. Here, the calculating means is:
For the designated component, the converted intensity ratio to a theoretical intensity scale based on the measured intensity ratio of the measured intensity of fluorescent X-rays from the component and the measured intensity of scattered X-ray radiation of the X-ray tube, A comparison is made as to whether or not the theoretical intensity ratio between the theoretical intensity of the fluorescent X-rays from the designated component and the theoretical intensity of the scattered radiation of the characteristic X-rays of the X-ray tube matches.

According to the third aspect of the present invention, the specified component is analyzed by the FP method which introduces the internal standard method using the characteristic X-ray scattered radiation of the X-ray tube as the internal standard line. Although the type is different, the same operation and effect as those of the device of claim 2 can be obtained.

According to a fourth aspect of the present invention, there is provided a fluorescent X-ray analyzer, comprising:
An X-ray tube for irradiating the next X-ray, a detecting means for measuring the intensity of secondary X-rays generated from the sample, and a designated component in the sample, wherein the designated component measured from the designated component is The measured intensity ratio between the measured intensity of the fluorescent X-rays and the measured intensity of the fluorescent X-rays from the internal standard element added to the sample in a predetermined amount, and the measured intensity ratio previously determined using the standard sample and the specified value Calculating means for calculating the content rate of the specified component by applying a calibration curve which is a correlation with the content rate of the component. That is, it is a fluorescent X-ray analyzer that analyzes a designated component by a calibration curve method in which an internal standard method using fluorescent X-rays from an internal standard element as an internal standard line is introduced. Here, the calibration curve is the designated intensity determined in advance using a theoretical intensity ratio between the theoretical intensity of the fluorescent X-ray from the designated component and the theoretical intensity of the fluorescent X-ray from the internal standard element. The component is corrected by a theoretical matrix correction coefficient using the component as a component to be corrected. That is, the analysis is performed by the SFP method included in the calibration curve method.

In the apparatus according to the fourth aspect, since the designated component is analyzed by the SFP method in which the internal standard method using fluorescent X-rays from the internal standard element as the internal standard line is used, the calibration method is used. The same effect as that of the FP method is also produced by the theoretical matrix correction coefficient, and the same effect as that of the apparatus of the first aspect is obtained.

According to a fifth aspect of the present invention, there is provided an X-ray fluorescence spectrometer comprising a calculation means and the like, wherein a calibration is performed by introducing an internal standard method using a background of X-ray fluorescence from the component as an internal standard line for a designated component. Analyze by linear method. Here, the calibration curve is
Theoretical matrix correction using the specified component, which is obtained in advance, using the theoretical intensity ratio between the theoretical intensity of the fluorescent X-rays from the specified component and the theoretical intensity of the background of the fluorescent X-rays as the component to be corrected It has been corrected by the coefficient. That is, the SF included in the calibration curve method
The analysis is performed by the P method.

In the apparatus according to the fifth aspect, the specified component is analyzed by the SFP method which introduces the internal standard method using the background of the fluorescent X-ray from the component as the internal standard line. Unlike the above-mentioned SFP method that introduced the internal standard method using the characteristic X-ray scattered radiation of the X-ray tube, when the sample contains an element having an absorption edge at the wavelength between the analytical line and the scattered line. Also, the theoretical matrix correction coefficient of the element does not become too large, even when the sample is thin,
Hardly affected by thickness. Therefore, a sufficiently accurate analysis can be performed on a sample having a wide composition range.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to a first embodiment of the present invention will be described below with reference to FIG. First, the configuration of this device will be described. The apparatus includes a sample table 8 on which a sample 13 is placed, an X-ray tube 1 for irradiating the sample 13 with primary X-rays 2, and a secondary X-ray such as fluorescent X-rays generated from the sample 13.
Detecting means 10 for measuring the intensity of the line 4. The detecting means 10 includes a spectroscopic element 5 for separating the secondary X-rays 4 generated from the sample 13 and a secondary X-ray 6 separated by the spectroscopic element 5.
And a detector 7 for measuring the intensity of the light. In addition, the apparatus converts the converted intensity to a theoretical intensity scale based on the measured intensity of the fluorescent X-rays 4 measured by the detection means 10 and the theoretical intensity of the fluorescent X-rays calculated by assuming the content of each component in the sample 13. Is calculated for each corresponding component, and the content rates of the respective assumed components are successively and approximately corrected to calculate the content rates of the respective components so that the two intensities coincide with each other. I have. That is, the apparatus of the first embodiment is an X-ray fluorescence analyzer that performs analysis by the FP method.

Here, the calculating means 16 of this apparatus calculates, for the specified component, the measured intensity of the fluorescent X-ray 4 from the component and the fluorescent X-ray from the internal standard element added to the sample 13 in a predetermined amount. 4, the converted intensity ratio to the theoretical intensity scale based on the measured intensity ratio with the measured intensity of 4, the theoretical intensity of the fluorescent X-ray from the specified component, and the fluorescent X from the internal standard element.
Compare whether the theoretical intensity ratio of the line with the theoretical intensity matches.

Next, regarding the operation of the apparatus of the first embodiment, an iron ore to which a predetermined amount of Co is added in the form of oxide powder Co ₂ O ₃ is referred to as a sample 13, and an internal standard element for the component Fe is referred to as Co. An example in which analysis is performed by designating the application of the internal standard method will be described. First, the sample 13 placed on the sample stage 8 is irradiated with primary X-rays 2 to measure the intensity of the fluorescent X-rays 4 generated from each component (element) of the sample 13. Based on the measured intensity, the calculating means 16 calculates the content of each component by the FP method, for example, in the following procedure.

(Step 1) A converted intensity based on each measured intensity is obtained. That is, for each component, the measured intensity is converted to a theoretical intensity scale using the device sensitivity coefficient. The apparatus sensitivity coefficient is obtained by measuring the standard sample 3 with this apparatus or an apparatus of the same type, and is stored in the calculating means 16. At this time, the designated Fe is obtained by the following equation (1).

[0022]

(Equation 1)

The device sensitivity coefficient A _Fe ,
On the right side of the equation (1) using B _Fe and C _Fe , the measured intensity of the measured intensity of the fluorescent X-ray Fe-Kβ1 from Fe and the measured intensity of the fluorescent X-ray Co-Kα from the internal standard element Co is shown. By substituting the ratio, the converted intensity ratio is obtained by converting the measured intensity ratio into a theoretical intensity scale. The other components are analyzed by the normal FP method which does not apply the internal standard method as before, so that the intensity of the fluorescent X-ray (analytical line) from the relevant component is obtained without taking the ratio with the intensity of the internal standard line. Is used to determine the apparatus sensitivity coefficient, and by substituting the measured intensity of the analytical line into the equation, a converted intensity is calculated by converting the measured intensity to a theoretical intensity scale.

(Step 2) An initial value of the content of each component is assumed from the intensity ratio between the converted intensity of each component and the theoretical intensity of fluorescent X-rays from the pure substance of the component.

(Step 3) The theoretical intensity of each fluorescent X-ray (including the internal standard line) is calculated from the composition assumed as described above. For the specified Fe, the theoretical intensity ratio with the theoretical intensity of the internal standard line is also calculated.

(Step 4) For the designated Fe, the content rate is updated by the following equation (2) from the converted intensity ratio calculated in step 1 and the theoretical intensity ratio calculated in step 3. For other components, the content is similarly updated based on the converted intensity obtained in step 1 and the theoretical intensity calculated in step 3. Since the internal standard element Co is added in a known and predetermined amount, the content is a fixed value.

[0027]

(Equation 2)

(Step 5) For each component, the content ratio of the nth time and the content ratio of the (n + 1) th time are compared, and the convergence is made when the change in the content ratio of all the components becomes equal to or less than a predetermined value.
If the convergence has not occurred, the procedure from step 3 is repeated.

That is, assuming the converted intensity obtained in step 1 and the content of each component in step 2, step 3
The theoretical intensities of the fluorescent X-rays calculated in Steps 4 and 5 are compared for each corresponding component in Steps 4 and 5, and by repeating Steps 3 to 5, the content rates of the assumed components are sequentially determined so that both intensities match. Approximately correct the calculation to calculate the content of each component. Here, for the designated Fe, the analysis line Fe
Step 1 instead of the converted intensity and the theoretical intensity of the Kβ1 line
The converted intensity ratio obtained in step 3 and the theoretical intensity ratio calculated in step 3 are compared in steps 4 and 5. In the repetition of steps 3 and 5, the assumed Fe content rate is adjusted so that the two intensity ratios match. Correction calculation is performed by successive approximation.

In order to explain the operation and effect of the apparatus of the first embodiment having the above configuration and operation, iron ore having three compositions as shown in Table 1 is assumed, and calculated theoretical strengths are shown in Table 2. .

[0031]

[Table 1]

[0032]

[Table 2]

As described above, in the FP method, the theoretical intensity of each fluorescent X-ray is calculated from the content of all the components of the sample.
For example, in a mineral powder sample, the content of a heavy element component such as Fe ₂ O ₃ to be analyzed is likely to have an error due to a mineral effect or a particle size effect. The light element component such as SiO ₂ , Al ₂ O ₃ , and MgO is likely to have an error. Content affects. On the other hand, in Tables 1 and 2, the samples 1-1 and 1-2 have different contents of only the light element components SiO ₂ and MgO.
Although it affects the theoretical intensity for e, it hardly affects the theoretical intensity ratio for Fe. This is because when a certain iron ore is used as a sample and its component Fe ₂ O ₃ is analyzed by the FP method, the light element components SiO ₂ , M
Even if an error of about 10% appears in the content of gO due to the mineral effect and the grain size effect, the Co-Kα line is converted to the internal standard line for the heavy element component Fe ₂ O ₃ to be analyzed as in the first embodiment. If the internal standard method is applied, the calculated Fe ₂ O
It shows that the content of ₃ has almost no effect.

On the other hand, although errors due to the mineral effect and the grain size effect are unlikely to appear in the content of heavy element components such as TiO ₂ , the content of TiO 2 in Samples 1-1 is 1 in Tables 1 and _2.
In the sample 1-3 increased by 0%, the theoretical intensity ratio of Fe is large. This is because when the intensity ratio of the analysis component actually changes due to the change in the content of the heavy element component other than the analysis component, the conventional internal standard is used according to the FP method as in the first embodiment. This shows that, unlike the standard calibration method using the method, the theoretical calculation can be performed properly including the change. Therefore, according to the apparatus of the first embodiment, sufficiently accurate analysis can be performed on the sample 13 having a wide composition range.

Next, the configuration of the device according to the second embodiment of the present invention will be described. This apparatus is also a fluorescent X-ray analyzer that includes the sample table 8, the X-ray tube 1, the detecting means 10, and the calculating means 26 and performs analysis by the FP method, similarly to the apparatus of the first embodiment. Here, the calculating means 2 of the device of the second embodiment
6 is, for the designated component, a converted intensity ratio to a theoretical intensity scale based on a measured intensity ratio of the measured intensity of the fluorescent X-ray 4 from the component and the measured intensity of the background of the fluorescent X-ray 4; A comparison is made as to whether or not the theoretical intensity ratio between the theoretical intensity of the fluorescent X-ray from the designated component and the theoretical intensity of the background of the fluorescent X-ray matches.

That is, in terms of operation, in the apparatus of the first embodiment, the fluorescent X-rays 4 from the internal standard element added to the sample 13 in a predetermined amount are used as the internal standard lines. The apparatus differs only in that the background of the fluorescent X-rays 4 from the designated component is used as an internal standard line. For example, when a rock is used as the sample 13 and the component Sr is analyzed by designating the application of the internal standard method, the background of the analytical line Sr-Kα is set as the internal standard line. Therefore, in the apparatus of the second embodiment, the sample 13
It is not necessary to add a predetermined amount of an internal standard element to the sample.

In the apparatus according to the second embodiment, the designated component is analyzed by the FP method in which the internal standard method using the background of the fluorescent X-ray from the component as the internal standard line is used. Although the type of line is different, the same operation and effect as those of the device of the first embodiment can be obtained. Also,
For example, in the analysis of Sr and the like in sample 13 which is rock,
Background and X-ray tube characteristics X described in the prior art
Unlike a normal calibration method in which an internal standard method using the scattered radiation as an internal standard line is introduced, even if the composition of the sample 13 changes greatly, it can be appropriately dealt with by theoretical calculation. Therefore, a sufficiently accurate analysis can be performed on the sample 13 having a wide composition range.

Next, the configuration of the device according to the third embodiment of the present invention will be described. This apparatus is also a fluorescent X-ray analyzer that includes the sample table 8, the X-ray tube 1, the detecting means 10, and the calculating means 36 and performs analysis by the FP method, similarly to the apparatus of the first embodiment. Here, the calculating means 3 of the device of the third embodiment
6 indicates the measured intensity of the fluorescent X-ray 4 from the designated component and the scattered radiation 4 of the characteristic X-ray of the X-ray tube 1.
The converted intensity ratio to the theoretical intensity scale based on the measured intensity ratio with the measured intensity of the above, the theoretical intensity of fluorescent X-rays from the designated component, the theoretical intensity of scattered X-rays of the X-ray tube 1 and Are compared with each other to determine whether or not the theoretical intensity ratios are the same.

That is, in terms of operation, in the apparatus of the first embodiment, the fluorescent X-rays 4 from the internal standard element added to the sample 13 in a predetermined amount are used as the internal standard lines. The apparatus is different only in that scattered radiation 4 of characteristic X-rays of the X-ray tube 1 is used as an internal standard line. For example, when the rock is designated as the sample 13 and the component Sr is designated to apply the internal standard method and the analysis is performed using the Rh tube as the X-ray tube 1, the analysis line Sr-K
For α-rays, Compton scattering of characteristic X-rays Rh-Kα-rays of the X-ray tube 1 is set as an internal standard line. Therefore, in the apparatus of the third embodiment, it is not necessary to add a predetermined amount of the internal standard element to the sample 13 as in the apparatus of the second embodiment.

In the apparatus according to the third embodiment, the specified component is analyzed by the FP method in which the internal standard method using the scattered radiation of the characteristic X-ray of the X-ray tube 1 as the internal standard line is used. Although the type of the standard line is different, the same operation and effect as those of the device of the second embodiment can be obtained.

Next, an apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. First, the configuration of this device will be described. This apparatus is provided with a sample stage 8, an X-ray tube 1, and a detecting means 10, similarly to the apparatus of the first embodiment. For the designated component in the sample 13, the measured intensity of the fluorescent X-ray 4 from the designated component measured by the detection means 10 and the fluorescent X-ray from the internal standard element added to the sample 13 in a predetermined amount Calculation means 46 is provided for calculating a content rate of the specified component by applying a calibration curve to the measured intensity ratio with the measured intensity of No. 4. This calibration curve is obtained in advance by calculating a calibration curve constant using the standard sample 3, and is a correlation between the measured intensity ratio and the content ratio of the specified component, and is stored in the calculating means 46. ing. That is, the apparatus according to the fourth embodiment performs a fluorescent X-ray analysis on a designated component by a calibration curve method in which an internal standard method using fluorescent X-rays from an internal standard element as an internal standard line is introduced.
It is a line analyzer.

Here, in the calculating means 46 of this apparatus, the calibration curve is corrected by a theoretical matrix correction coefficient using the specified component as a component to be corrected. The theoretical matrix correction coefficient is calculated using a theoretical intensity ratio between the theoretical intensity of the fluorescent X-rays from the specified component and the theoretical intensity of the fluorescent X-rays from the internal standard element without using the actual standard sample. It has been requested in advance. That is,
The apparatus according to the fourth embodiment performs analysis by the SFP method included in the calibration curve method.

Next, the calibration curve (including the theoretical matrix correction coefficient) stored in the calculating means 46 of the apparatus.
The following describes how to obtain the value. Note that this method is different from the method of the invention of Japanese Patent No. 3059403 in which the Compton scattered radiation of the characteristic X-ray of the X-ray tube is used as the internal standard line in the type of the internal standard line used.

In X-ray fluorescence analysis, generally, sample 1
3, if the metal element or coexisting element as the main component is contained only as one form of oxide, treat it as an oxide and analyze its content. Handle and analyze its content. In the present embodiment, Fe O, Fe ₂ O ₃ or the like of iron ore containing iron (Fe) in different forms in order to handle easily as a sample 13, a major component assuming iron alone analyze the iron content I do. Specifically, the sample 13 was prepared by mixing a main component, which is a simple substance of iron, with an additive component of coexisting components, that is, silicon dioxide,
It is assumed that it is composed of calcium oxide and the like, and a residue designated as a base component of the coexisting components, that is, oxygen.

Here, the main component is a designated component, which means a calibration curve based on the intensity ratio between the fluorescent X-ray and the internal standard line. The additive component is a calibration component based on the fluorescent X-ray. A line is determined, and the analysis value of the content is used for correcting the analysis value of the main component. The main component is not always one in the sample 13. For example, in the present embodiment, manganese oxide is treated as an additional component, but a calibration curve based on the intensity ratio between the fluorescent X-ray and the internal standard line is used. Manganese oxide other than iron may be used as the main component as long as accurate analysis as a whole can be obtained by obtaining and treating it as the main component.

Now, the calculating means 46 repeatedly calculates the calibration curve (the following equation (3)) for iron and the calibration curve (the following equation (4)) for the correction component including the coexisting element i as viewed from iron. content W _i of content W _Fe and pressure correction component of iron in the sample 13 is obtained. The coexisting element j in the formula (4) is a coexisting element j from the viewpoint of the element i.
Also includes iron.

[0047]

(Equation 3)

[0048]

(Equation 4)

Here, the equation (3) represents a calibration curve based on the composition consisting of only iron and oxygen for a sample to which a predetermined amount of the internal standard element is added (hereinafter, a reference curve to be distinguished from a virtual calibration curve described later). The expression in the first parenthesis on the right side indicates the uncorrected iron content based on the reference calibration curve, and includes the reference calibration curve constants a, b, and c. The equation in the second parenthesis is a correction term relating to absorption and excitation of the fluorescent X-rays 4 of iron, and is a coexisting element which corrects a sample to which a predetermined amount of the internal standard element is added based on a composition consisting of only iron and oxygen. j includes a matrix correction coefficient α _j for iron. In the conventional ordinary calibration curve method, the standard sample 3 is measured, and all of the reference calibration curve constants a, b, and c and the matrix correction coefficient α _j are experimentally obtained.
In the present embodiment using the SFP method, the matrix correction coefficient α _j is theoretically obtained by assuming a standard sample without using the actual standard sample 3, and stored in the calculating means 46 as a theoretical matrix correction coefficient. . In Equation (3), for simplicity, a part to be described as α _Fej is referred to as α _j ,
a _Fe, b _Fe, the c _Fe a, b, and c, are denoted for short subscripts _Fe.

In the present embodiment, the iron ore as the sample 13 has a typical composition, the iron content is W _Fem , and the first hypothetical element to which a predetermined amount of the internal standard element cobalt (Co) is added. Assuming a sample, based on the assumed composition, the theoretical intensity of fluorescent X-rays generated from iron in the first virtual sample;
The first virtual intensity ratio is calculated by calculating the theoretical intensity of the fluorescent X-ray generated from cobalt in the first virtual sample and calculating the ratio of the two intensities.
^T1 I _Fe . The calculation of this theoretical strength has conventionally been FP
Is what is done in the law. Also, as compared with the first virtual sample, a second virtual sample is assumed in which the iron content is higher by a certain amount ΔW _Fe , the oxygen content is lower by ΔW _Fe by that amount, and the other contents are unchanged. Similarly, the second virtual intensity ratio ^T2 _IFe is calculated based on the assumed composition. Then, the first and second virtual intensity ratios ^T1 I _Fe and ^T2 I _Fe and the iron contents W _Fem and W in the first and second virtual samples are obtained.
The correlation with _Fem + ΔW _Fe is determined in the form of the following equation (5) as a virtual calibration curve that is a straight line. This virtual calibration curve is based on a representative composition. Note that the subscript ^T means a numerical value based on a hypothesis.

[0051]

(Equation 5)

Further, as compared with the first virtual sample, the content of one additive component, for example, silicon dioxide, is larger by a certain amount ΔW _Si , the oxygen content is smaller by ΔW _Si , and the other content remains unchanged. 3 virtual samples assumes, based on the assumed composition, wherein similarly to the third to calculate the virtual intensity ratio ^T3 I _Fe, the virtual calibration line or equation to the third virtual intensity ratio ^T3 I _Fe (5) Is applied to determine the iron content ^T X _Fe in the third virtual sample. The iron content of the third virtual sample is
Since it is assumed that the content is the same as that of the first virtual sample, the third virtual sample has only the silicon dioxide in the additive component that is larger by ΔW _Si, so the virtual correction coefficient ^T α _Si of silicon with respect to iron is given by the following equation (6). Ask from. At this time, W _Fe = W _Fem .

[0053]

(Equation 6)

[0054] Similarly, for each pressure correction component, assuming the third virtual samples, corrected on the basis of the typical composition, the virtual correction coefficient ^T alpha _j to iron is obtained from the following equation (7).

[0055]

(Equation 7)

The content W _j of the additive component containing the coexisting element j in the third virtual sample is expressed by the following formula (8) with the content W _jm of the same component in the first virtual sample, that is, the representative composition. In a relationship.

[0057]

(Equation 8)

By substituting equation (8) into equation (7), the following equation (9) can be obtained.

[0059]

(Equation 9)

Here, paying attention to the product of ^T X _Fe of the formula (9) and the first parenthesis, and comparing it with the formula (7), the ^T X _Fe is a typical composition of a certain sample. The uncorrected iron content based on the reference virtual calibration curve. The expression in the first parenthesis indicates that the sample has a content of the added component containing the coexisting element j which is smaller than the representative composition by W _jm. It is small, that is, does not include an additional correction component, and means that a correction corresponding thereto is added. That is, the product of ^T x _Fe and the first bracket indicates the corrected iron content of the sample consisting of only iron and oxygen. In other words, as shown in the following equation (10), the additive component is also for samples 13 may include a content X _Fe iron uncorrected composition comprising only iron and oxygen by reference calibration curve as a reference.

[0061]

(Equation 10)

Therefore, this X _Fe is the same as the expression in the first parenthesis on the right side of the expression (3), as shown in the following expression (11).

[0063]

[Equation 11]

Since both equations (9) and (3) represent the corrected iron content W _Fe , equation (9) can be expressed by the following equation (12). It can be transformed as in equation (13).

[0065]

(Equation 12)

[0066]

(Equation 13)

That is, when the analysis is performed using the calibration curve based on the intensity ratio of the fluorescent X-rays 6 of iron and cobalt using the equation (12), the virtual correction coefficient ^T α _j for correcting based on the representative composition. From the content W _jm of the additive component in the typical composition, a matrix correction coefficient α _j for correcting based on the composition consisting of only iron and oxygen is obtained, and stored in the calculating means 46 as a theoretical matrix correction coefficient. A known theoretical value is used for the calibration coefficient for the additive component, that is, the correction coefficient α _ij in equation (4), as in the conventional SFP method. As described above, the reference calibration curve constants a, b, and c in the equation (3) are:
It is determined experimentally as in the case of the conventional normal calibration method. The calibration curve constants a _i , b _i , and c _i in equation (4) are similarly obtained experimentally.

Accordingly, a reference calibration curve (Equation (3)) for iron and a calibration curve (Equation (4)) for the correction component are obtained, and the calibration curve for iron, which is the designated component, and other calibration curves. It is stored in the calculating means 46 as a calibration curve for the component.

Next, regarding the operation of the apparatus of the fourth embodiment, an iron ore to which a predetermined amount of Co is added in the form of oxide powder Co ₂ O ₃ is used as a sample 13, and an internal standard element of the component Fe is Co. An example in which analysis is performed by designating the application of the internal standard method will be described. First, the sample 13 placed on the sample stage 8 is irradiated with primary X-rays 2 to measure the intensity of the fluorescent X-rays 4 generated from each component (element) of the sample 13. Based on the measured intensity, the calculating means 46 calculates the content of each component by the SFP method incorporating the internal standard method.

[0070] Specifically, for the specified ingredients Fe, to measure the intensity ratio of the measured intensity of the measured intensity and the internal standard line Co -Keiarufa lines was measured by the detection means 10 analyzes ray Fe -Kβ ₁ line, Applying the calibration curve of equation (3), and applying the calibration curve of equation (4) to the measured intensity of each analysis line measured by the detection means 10 in the same manner as in the conventional SFP method for other components, The Fe content is calculated by combining all the equations.

In the apparatus according to the fourth embodiment, the specified component is analyzed by the SFP method in which an internal standard method using fluorescent X-rays from the internal standard element as an internal standard line is used. However, due to the theoretical matrix correction factor, F
The same operation as that of the P method also occurs, and the same operation and effect as those of the device of the first embodiment are obtained.

Next, the configuration of the device according to the fifth embodiment of the present invention will be described. This apparatus also includes a sample stage 8, an X-ray tube 1, and a detecting means 10, similarly to the apparatus of the fourth embodiment. For the designated component in the sample 13, the measured intensity ratio of the measured intensity of the fluorescent X-ray 4 from the designated component measured by the detection means 10 to the measured intensity of the background of the fluorescent X-ray 4 is obtained. And a calculating means 56 for applying a calibration curve to calculate the content of the specified component. This calibration curve is obtained in advance by calculating a calibration curve constant using the standard sample 3, and is a correlation between the measured intensity ratio and the content rate of the specified component, and is stored in the calculation means 56. ing. That is, the fifth
The apparatus of the embodiment is an X-ray fluorescence spectrometer that analyzes a designated component by a calibration curve method using an internal standard method in which the background of the X-ray fluorescence from the component is used as an internal standard line.

Here, in the calculation means 56 of this apparatus, the calibration curve is corrected by a theoretical matrix correction coefficient using the specified component as a component to be corrected. That is, the analysis is performed by the SFP method included in the calibration curve method. Although the theoretical matrix correction coefficient is obtained in advance without using an actual standard sample, the apparatus of the fifth embodiment uses the theoretical intensity of the fluorescent X-ray from the designated component and the fluorescent X-ray of the fluorescent X-ray. It is obtained using the ratio of the theoretical intensity to the theoretical intensity of the background.

The calibration curve (including the theoretical matrix correction coefficient) stored in the calculating means 56 of the apparatus of the fifth embodiment is obtained by dividing the internal standard line in the above-described method of the apparatus of the fourth embodiment. It can be obtained by replacing the fluorescent X-rays 4 from the standard element with the background of the fluorescent X-rays 4 from the designated component.

Therefore, in terms of operation, in the apparatus of the fourth embodiment, the fluorescent X-rays 4 from the internal standard element added to the sample 13 in a predetermined amount are used as the internal standard lines. The apparatus differs only in that the background of the fluorescent X-rays 4 from the designated component is used as an internal standard line. For example, when a rock is used as the sample 13 and the component Sr is analyzed by designating the application of the internal standard method, the background of the analytical line Sr-Kα is set as the internal standard line. Therefore, in the apparatus of the fifth embodiment, the sample 13
It is not necessary to add a predetermined amount of an internal standard element to the sample.

In the apparatus according to the fifth embodiment, the designated component is analyzed by the SFP method which introduces the internal standard method using the background of the fluorescent X-ray from the component as the internal standard line. Unlike the SFP method, which introduced the internal standard method using the scattered X-ray characteristics of the X-ray tube described in the above, first, the sample contains an element that has an absorption edge at the wavelength between the analytical line and the scattered line. In such a case, the theoretical matrix correction coefficient of the element does not become too large and the error does not increase. For example, in a case where a rock is used as the sample 13 and the component Sr is analyzed, the theoretical matrix correction coefficient of the additive component with respect to Sr corresponds to the measured intensity ratio between the Sr-Kα line and the background used in the apparatus of the fifth embodiment. Correcting the calibration curve to be applied (α _{j in} equation (3))
Is used in the normal SFP method without introducing the internal standard method.
Table 3 shows a comparison with a calibration curve applied to the measured intensity of the r-Kα ray (corresponding to α _ij in equation (4)). Note that SiO ₂ is used as a base component.

[0077]

[Table 3]

That is, in the apparatus according to the fifth embodiment, since the theoretical matrix correction coefficients of the additive component to the component Sr to be analyzed are all sufficiently small, the influence of the analytical error of the additive component on the analysis of Sr is also sufficient. Small.

Further, in the apparatus of the fifth embodiment, even when the sample is thin, the influence of the thickness is hard to appear. Therefore, a sufficiently accurate analysis can be performed on a sample having a wide composition range.

[0080]

As described in detail above, according to the X-ray fluorescence spectrometer of the present invention which performs analysis by the FP method and the SFP method in which the introduction of the internal standard method is expanded, a sample having a wide composition range is sufficiently accurate. Analysis.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an X-ray fluorescence analyzer according to first to fifth embodiments of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... X-ray tube, 2 ... primary X-ray, 3 ... standard sample, 4 ... secondary X-ray generated from sample, 10 ... detection means, 13 ... sample, 1
6, 26, 36, 46, 56... Calculation means.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G001 AA01 AA09 BA04 CA01 EA01 FA01 FA09 FA12 FA30 GA01 GA03 KA01 LA02 LA03 LA06 MA04 NA03 NA06 NA07 NA10 NA11 NA16 NA17 NA20

Claims (5)

[Claims] 1. An X-ray tube for irradiating a sample with primary X-rays, a detecting means for measuring the intensity of secondary X-rays generated from the sample, and a measuring intensity of fluorescent X-rays measured by the detecting means. The converted intensity to the theoretical intensity scale and the theoretical intensity of the fluorescent X-rays calculated by assuming the content of each component in the sample are compared for each corresponding component, and the above-mentioned components are assumed so that both intensities match. Calculating means for successively and approximately correcting and calculating the content of
In the X-ray analyzer, the calculating means measures the measured intensity of the fluorescent X-ray from the specified component and the measured intensity of the fluorescent X-ray from the internal standard element added to the sample in a predetermined amount. Whether the theoretical intensity ratio converted to the theoretical intensity scale based on the intensity ratio and the theoretical intensity ratio of the theoretical intensity of the fluorescent X-rays from the specified component and the theoretical intensity of the fluorescent X-rays from the internal standard element match X-ray fluorescence spectrometer characterized by contrasting. 2. An X-ray tube for irradiating a sample with primary X-rays, a detecting means for measuring the intensity of secondary X-rays generated from the sample, and a measuring intensity of the fluorescent X-ray measured by the detecting means. The converted intensity to the theoretical intensity scale and the theoretical intensity of the fluorescent X-rays calculated by assuming the content of each component in the sample are compared for each corresponding component, and the above-mentioned components are assumed so that both intensities match. Calculating means for successively and approximately correcting and calculating the content of
In the X-ray analyzer, the calculating means converts the designated component to a theoretical intensity scale based on a measured intensity ratio of the measured intensity of the fluorescent X-ray from the component and the measured intensity of the background of the fluorescent X-ray. Comparing the converted intensity ratio with a theoretical intensity ratio of the theoretical intensity of the fluorescent X-rays from the designated component to the theoretical intensity of the background of the fluorescent X-rays. Analysis equipment. 3. An X-ray tube for irradiating a sample with primary X-rays, a detecting means for measuring the intensity of secondary X-rays generated from the sample, and a measuring means for measuring the intensity of fluorescent X-rays measured by the detecting means. The converted intensity to the theoretical intensity scale and the theoretical intensity of the fluorescent X-rays calculated by assuming the content of each component in the sample are compared for each corresponding component, and the above-mentioned components are assumed so that both intensities match. Calculating means for successively and approximately correcting and calculating the content of
In the X-ray analysis apparatus, the calculation unit may calculate a theoretical value of a designated component based on a measured intensity ratio between a measured intensity of fluorescent X-rays from the component and a measured intensity of scattered X-ray characteristics of the X-ray tube. Intensity ratio converted to intensity scale and fluorescence X from the specified component
An X-ray fluorescence analyzer characterized by comparing whether the theoretical intensity ratio between the theoretical intensity of the X-ray tube and the theoretical intensity of the scattered X-ray characteristic of the X-ray tube matches. 4. An X-ray tube for irradiating a sample with primary X-rays, detection means for measuring the intensity of secondary X-rays generated from the sample, and a specified component in the sample measured by the detection means The measured intensity ratio between the measured intensity of the fluorescent X-rays from the specified component and the measured intensity of the fluorescent X-rays from the internal standard element added to the sample in a predetermined amount was determined in advance using a standard sample. Applying a calibration curve which is a correlation between the measured intensity ratio and the content of the specified component, and calculating means for calculating the content of the specified component.
In the line analyzer, the calibration curve may be obtained by using the theoretical intensity ratio between the theoretical intensity of fluorescent X-rays from the specified component and the theoretical intensity of fluorescent X-rays from the internal standard element. An X-ray fluorescence spectrometer which is corrected by a theoretical matrix correction coefficient using the corrected component as a component to be corrected. 5. An X-ray tube for irradiating a sample with primary X-rays, detection means for measuring the intensity of secondary X-rays generated from the sample, and a designated component in the sample measured by the detection means The measured intensity ratio between the measured intensity of the fluorescent X-rays from the designated component and the measured intensity of the background of the fluorescent X-rays, the measured intensity ratio previously determined using a standard sample, and the designated component Applying a calibration curve that is a correlation with the content of the X-ray fluorescence spectrometer provided with calculation means for calculating the content of the specified component, wherein the calibration curve is obtained from the specified component. Is corrected by a theoretical matrix correction coefficient using the designated component as a component to be corrected, which is obtained in advance using a theoretical intensity ratio between the theoretical intensity of the fluorescent X-ray and the theoretical intensity of the background of the fluorescent X-ray. An X-ray fluorescence analyzer.