JP2001249089A - Method and apparatus for fluorescence x-ray analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus capable of properly searching for fluorescence X-rays or component to be used in the overlap correction of analytic rays in fluorescence X-ray analysis to display the same. SOLUTION: The theoretical intensities of analytic rays and a jamming rays are calculated on the basis of the composition data of a sample 13 and the intensity ratio of the jamming rays to the analytic rays in the wavelength of the analytic rays is calculated as a degree of influence of overlap on the basis of both theoretical intensities and the degree of influence of the overlap of respective jamming rays is compared with a predetermined value and fluorescence X-rays to be used in the overlap correction of the analytic rays or a component for generating the same is detected to be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for retrieving fluorescent X-rays or components to be used for correcting the overlap of analytical lines in fluorescent X-ray analysis.

[0002]

2. Description of the Related Art Conventionally, for example, in wavelength-dispersive X-ray fluorescence analysis using a spectroscopic element, the X-ray fluorescence to be measured has a wavelength (or energy) depending on the resolution of an analyzer.
Has a certain extent. Such a fluorescent X-ray measurement result (relationship between intensity and wavelength or energy) is called a spectrum, and another fluorescent X-ray whose wavelength is close to that of an analysis line, which is the fluorescent X-ray to be measured, is an interference line. It may overlap in part of the spectrum. In order to remove the influence of such overlapping of the interference lines and accurately analyze the analysis line, as described in, for example, Japanese Patent Application Laid-Open No. 10-123071 and Japanese Patent Application No. 11-196153, measurement of the interference line is performed. The overlap is corrected using the intensity or the theoretical intensity or the content of the component that generates the interference line.

[0003]

However, the degree to which the interference line appears with respect to the analysis line depends on the composition of the sample and the measurement conditions of the detection means of the analyzer used. It is necessary to determine for each measurement whether fluorescent X-rays or components should be used for the overlap correction as having an influence on the measurement of the analytical line.
It is not easy to measure the spectrum in the vicinity of the analysis line and to check the resulting peak against the wavelength table, for example, because technical knowledge on X-ray fluorescence analysis is required. That is, if an interference line can be identified, there are various methods for performing overlap correction using the intensity or the like as described above, but it is not easy to appropriately identify the interference line that affects the measurement of the analysis line.

The present invention has been made in view of the above-mentioned conventional problems, and provides a method and apparatus capable of appropriately searching and displaying fluorescent X-rays or components to be used for correction of overlap of analytical lines in fluorescent X-ray analysis. The purpose is to do.

[0005]

In order to achieve the above object, in the X-ray fluorescence analysis method of the present invention, the intensity of X-ray fluorescence generated by irradiating a sample with primary X-rays from an X-ray source is measured. In the X-ray fluorescence analysis method of measuring by the detection means, first, based on the representative composition of the sample type to be analyzed, an analysis line which is the X-ray fluorescence to be measured, and a predetermined wavelength range with respect to the analysis line And the interference line, which is a fluorescent X-ray in the vicinity,
Calculate the theoretical strength for each. Then, based on the theoretical intensity of the analysis line and the interference line, the intensity ratio of the interference line to the analysis line at the wavelength of the analysis line is determined as the degree of influence of the overlap, and the degree of influence of the overlap of each interference line is compared with a predetermined value. Thereby, the fluorescent X-rays to be used for the overlap correction of the analysis lines or the components that generate the fluorescent X-rays are retrieved and displayed.

According to the method of the first aspect, the influence of the overlap of the interference line can be obtained with high reliability based on the theoretical intensity of the analysis line and the interference line calculated based on the composition information of the sample. The X-ray fluorescence or the component to be used for the correction of the overlap of the analysis lines can be appropriately searched and displayed.

According to a second aspect of the present invention, in the method of the first aspect, the detecting means includes a spectroscopic element for separating the fluorescent X-rays generated from the sample and a fluorescent X-ray separated by the spectroscopic element. And a detector for generating a pulse having a pulse height corresponding to the energy of the fluorescent X-rays by the number corresponding to the intensity, and a pulse height analyzer for selecting pulses in a predetermined pulse height range among the pulses generated by the detector. And That is, it is a wavelength dispersive X-ray fluorescence analysis method. The theoretical intensity of the representative composition of the sample type to be analyzed with respect to the disturbing line, which is a second-order or higher-order line separated by the spectroscopic element, the wave height distribution curve obtained by the wave height analyzer, and the predetermined wave height , The intensity ratio of the higher-order line to the primary line is determined as the inter-order intensity ratio, and the degree of influence of the overlap is determined using the inter-order intensity ratio.

According to the method of the second aspect, the degree of influence of the overlap is determined by appropriately considering not only the primary line but also the interference line which is a higher-order line of the second or higher order. The fluorescent X-rays or components to be used can be more appropriately searched and displayed.

According to a third aspect of the present invention, in the method of the second aspect, an escape peak appearing in a peak distribution curve of the peak analyzer is determined in advance.
The intensity ratio of the escape peak to the interference line, which is a higher-order line that generates an escape peak, is determined as an escape peak intensity ratio, and the inter-order intensity ratio is determined using the escape peak intensity ratio.

According to the third aspect of the present invention, the influence of the overlap is determined by appropriately considering the interference line, which is a higher-order line including the escape peak, so that the fluorescent X-ray to be used for the overlap correction of the analysis line is obtained. Alternatively, components can be searched and displayed more appropriately.

According to a fourth aspect of the present invention, there is provided an X-ray fluorescence analyzer.
Used in the method of (1), wherein the sample is applied from an X-ray source to
An X-ray fluorescence analyzer for measuring the intensity of X-ray fluorescence generated by irradiating the next X-ray with a detection unit includes a search unit and a display unit. The search means includes, based on a representative composition of a sample type to be analyzed, an analysis line that is a fluorescent X-ray to be measured, and a fluorescent X-ray that is close to the analysis line within a predetermined wavelength range. Calculate the theoretical intensity of the interference line and the theoretical intensity of the interference line, and calculate the intensity ratio of the interference line to the analysis line at the wavelength of the analysis line as the influence of the overlap based on the theoretical intensity of the analysis line and the interference line. Is compared with a predetermined value, thereby searching for a fluorescent X-ray or a component that generates the fluorescent X-ray to be used for the overlap correction of the analysis line. The display means displays a result searched by the search means. According to the device of the fourth aspect, the same operation and effect as those of the method of the first aspect can be obtained.

The X-ray fluorescence spectrometer according to claim 5 is the second invention.
5. The apparatus according to claim 4, wherein said detecting means first detects fluorescence X generated from the sample.
A spectroscopic element that disperses the X-rays, a detector that receives fluorescent X-rays separated by the spectroscopic element and generates a number of pulses having a wave height corresponding to the energy of the fluorescent X-rays according to the intensity, and a detector including the detector. A pulse height analyzer for selecting a pulse having a predetermined pulse height in the generated pulses. That is, it is a wavelength dispersive X-ray fluorescence analyzer. Then, the search means determines the theoretical intensity of the representative composition of the sample type to be analyzed and the wave height distribution by the wave height analyzer with respect to the disturbing line, which is a second-order or higher-order line that is spectrally separated by the spectral element. Based on the curve and the predetermined wave height range, the intensity ratio of the higher-order line to the primary line is determined as the inter-order intensity ratio, and the degree of influence of the overlap is determined using the inter-order intensity ratio.
According to the device of the fifth aspect, the same operation and effect as the method of the second aspect can be obtained.

[0013] The X-ray fluorescence spectrometer according to the sixth aspect is the third aspect of the present invention.
6. The apparatus according to claim 5, wherein the search means is configured to detect an escape peak which appears in a wave height distribution curve of the wave height analyzer with respect to a disturbance line which is a higher-order line which generates an escape peak. The intensity ratio of the escape peak is stored as an escape peak intensity ratio, and the inter-order intensity ratio is obtained using the stored escape peak intensity ratio. According to the device of the sixth aspect, the same operation and effect as those of the method of the third aspect can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an X-ray fluorescence analysis method according to an embodiment of the present invention will be described. First, an X-ray fluorescence analyzer used in this method will be described with reference to FIG. The apparatus first includes a sample stage 8 on which a sample 13 is placed.
And an X-ray source 1 such as an X-ray tube for irradiating the sample 13 with primary X-rays 2, and a detecting means 10 for measuring the intensity of fluorescent X-rays 4 generated from the sample 13. The detecting means 10 includes a spectroscopic element 5 for separating the fluorescent X-rays 4 generated from the sample 13,
A detector 7 that receives the fluorescent X-rays 6 separated by the spectroscopic element 5 and generates pulses of a wave height (voltage) corresponding to the energy of the fluorescent X-rays 6 by the number corresponding to the intensity, and the detector 7 And a pulse height analyzer 9 for selecting pulses generated within a predetermined pulse height range from the generated pulses.

The apparatus further comprises the following search means 11
And display means 12. The search means 11 comprises:
Based on the representative composition of the type of the sample 13 to be analyzed, an analysis line which is the fluorescent X-ray 4 to be measured and an interference which is the fluorescent X-ray 4 near the analysis line within a predetermined wavelength range. For each line, calculate the theoretical intensity, and based on the theoretical intensity of the analytical line and the disturbing line, calculate the intensity ratio of the disturbing line to the analytical line at the wavelength of the analyzing line as the degree of influence of the overlap. By comparing the degree of influence with a predetermined value, a search is made for the fluorescent X-rays 4 to be used for the overlap correction of the analysis lines or the components generating the fluorescent X-rays.

The search means 11 calculates the theoretical intensity of the representative composition of the sample type to be analyzed with respect to the interference line, which is a higher-order line of second or higher order, which is separated by the spectroscopic element 5 and the wave height analysis. The intensity ratio of the higher-order line to the primary line is determined as the inter-order intensity ratio based on the peak-height distribution curve in the detector 9 and the predetermined range of the peak height, and the degree of influence of the overlap is determined using the inter-order intensity ratio. . Further, the search means 11 stores, as an escape peak intensity ratio, an escape peak intensity ratio of an escape peak appearing in the wave height distribution curve of the wave height analyzer 9 with respect to a disturbance line which is a higher-order line generating the escape peak. Then, the inter-order intensity ratio is obtained using the stored escape peak intensity ratio. The display means 12 is, for example, C
RT, the result of the search by the search means 11 is displayed.

Next, an X-ray fluorescence analysis method of this embodiment using this apparatus will be described. First, based on the typical composition of the variety of the sample 13 to be analyzed, the search means 11
As a result, the analysis line i which is the fluorescent X-ray 4 to be measured and the interference line j which is the fluorescent X-ray 4 near the analysis line i within a predetermined wavelength range (retrieved from the characteristic X-ray wavelength table). , Respectively, are usually obtained in plural numbers), and the theoretical intensities Ii and Ij are respectively calculated by the fundamental parameter method. The predetermined wavelength range is a range in which another fluorescent X-ray whose wavelength is close to the analysis line may overlap in a part of the spectrum, and is appropriately set in advance, for example, for each analysis line.

In the measurement of the analytical line, the background is measured at the wavelengths on both sides of the peak, and the net intensity is obtained by subtracting the background. The wavelength (peak) of another fluorescent X-ray is different from that of the analytical line. If it is outside the measured wavelength of the ground, it is removed including the overlap of another fluorescent X-ray at the stage of obtaining the net intensity by subtracting the background, so that it is not necessary to treat it as an interference line.
That is, such fluorescent X-rays are not included in the fluorescent X-rays that are in the vicinity of the analysis line within a predetermined wavelength range.

In the method of this embodiment, not only the primary line, but also a disturbing line which is a higher-order line of the second or higher order is considered.
That is, as described below, with respect to the disturbing line, which is a second-order or higher-order line separated by the spectroscopic element 5, the theoretical intensity of the representative composition of the sample type to be analyzed and the wave height The intensity ratio of the higher-order line to the primary line is determined as the inter-order intensity ratio R _hi j based on the wave height distribution curve in the analyzer 9 and the predetermined wave height range. As described below, the inter-order intensity ratio R _hi j is the same as the intensity ratio R _re j between the primary line and the higher-order line due to the difference in the reflection characteristics of the spectroscopic element 5 and the counting efficiency of the detector 7. It is the product of the intensity ratio R _ph j and the difference in attenuation in the pulse height analyzer 9 between the two.

First, using the representative composition of the sample type to be analyzed, the spectroscopic element 5 used for each interference line from the secondary line is used.
The theoretical intensity is obtained up to a higher-order line of an order that can be reflected (diffraction, spectral) by the above-described method, and stored as the relative intensity ratio R _re j in which the value of the primary line is set to 1 and stored in the search means 11. deep. Here, the intensity to be obtained is obtained as an integral measurement without using the lower limit and the upper limit of the predetermined range of the wave height of the wave height analyzer 9 determined by the lower limit and the upper limit (the entire peak value range).

Next, the intensity ratio R _ph j with respect to the attenuation by the selection in the peak height analyzer 9 based on the predetermined range of the peak height determined by the lower limit value and the upper limit value is obtained. for that reason,
The resolution (half width) ER _rp of the peak distribution curve of the primary line (energy: E _rp ) is measured in advance by the detector 7 and the peak height analyzer 9 to be used, and stored in the search means 11.
Regarding the wave height distribution curve of the higher-order line, the shape is assumed to be Gaussian, and the resolution ER is stored as 1 which is inversely proportional to the square root of the energy E for the same detector as shown in the following equation (1). It is calculated from the resolution ER _rp of the next line.

ER = (E _rp / E) ^1/2 · ER _rp (1)

Here, the energy E is inversely proportional to the wavelength λ and is obtained by the following equation (2). The energy E of the higher-order line is
It is a value obtained by multiplying the energy ER of the primary line by the order. Note that h is a constant.

E = h / λ (2)

Further, in the method of this embodiment, a higher-order interference line is considered, including an escape peak appearing in a peak distribution curve of a peak analyzer. For example, a case where a gas flow type proportional counter using P-10 gas is used as the detector 7 and the K of argon gas is used.
When measuring a fluorescent X-ray having an energy larger than the energy at the absorption edge, an escape peak appears at an energy position smaller than the original fluorescent X-ray energy by the energy of the Ar-Kα ray. Therefore, in the method of this embodiment, similarly to the wave height distribution curve of the higher-order line, the shape of the wave height distribution curve of the escape peak assumes a Gaussian distribution, and the escape peak relative to the intensity of the peak of the original higher-order line. The search unit 11 obtains the ratio of the (vertex) intensities in advance by measuring it as an escape peak intensity ratio.
To be stored.

Then, based on the resolution ER _rp and the escape peak intensity ratio for the stored primary line,
In the wave height distribution curve of the higher-order line, the ratio of the intensity within the predetermined wave height at the higher-order line and its escape peak to the overall intensity of the higher-order line and its escape peak is set to 1 for the primary line. Relative intensity ratio (intensity ratio due to difference in attenuation in wave height analyzer 9) R _ph
Calculate as j.

The intensity ratio R _rej relating to the reflection characteristics of the spectral element 5 and the counting efficiency of the detector 7 stored as described above,
As a product of the obtained intensity ratio R _ph j relating to the attenuation in the wave height analyzer 9, the inter-order intensity ratio R _hi j of the higher-order line with respect to the primary line is calculated by the following equation (3). The inter-order intensity ratio R _hi j also has a value of 1 for the primary line.

R _hi j = R _re j · R _ph j (3)

Next, the spectral angle at the spectral element 5, that is, 2θ,
Consider the effect of the difference between the analysis line and the interference line (corresponding to the wavelength). First, a spectrum using 2θ and the measured intensity as axes is measured in an apparatus to be used, and the half value width for each interference line is stored in the search means 11. Then, assuming that the shape of the profile of the interference line is a combination of a Gaussian distribution and a Lorentz distribution, based on the stored half-value width, the spectral angle of the analysis line with respect to the peak intensity Ia of the interference line is calculated as in the following equation (4). Is calculated by calculation as an intensity ratio R _of j based on the spectral angle difference.

R _of j = Ib / Ia (4)

The theoretical intensity Ij of the interference line obtained as described above
, The order intensity ratio R _hi j and the intensity ratio R due to the spectral angle difference
_{From the value of} j, the intensity I _ov j of the interference line overlapping the analysis line at the wavelength of the analysis line is calculated by the following equation (5).

I _ov j = I j · R _hi j · R _of j (5)

Further, from the intensity I _ov j of the interference line at the wavelength of the analysis line and the theoretical intensity Ii of the analysis line obtained above,
As shown in the following equation (6), the intensity ratio of the interference line to the analysis line at the wavelength of the analysis line is calculated as the degree of influence IR of the overlap.

IR = _Iovj / Ii (6)

The degree of influence IR of the overlap takes into account the measurement conditions of the spectroscopic element 5 and the detector 7 of the apparatus to be used. It is necessary to find the degree of influence IR of the overlap. Conversely, if the degree of influence IR of the overlap is to be obtained, the setting of the measurement conditions is changed, and even if the measurement is not performed on the sample 13 to be analyzed under the same conditions, the measurement is performed with less influence of the interference line. You can also find conditions. Thus, the theoretical intensities Ii, Ij of the analysis line and the interference line
The degree of overlap IR is obtained based on the following equation.
By comparing R with a predetermined value, for example, a disturbing line having an overlapping degree of influence IR equal to or more than a predetermined value of 0.01 is searched (selected) as a fluorescent X-ray to be used for correcting the overlap of the analysis lines.
Then, the search result is displayed on the display unit 12.

As a result of comparing the degree of influence IR of each interference line with a predetermined value, what is searched and displayed as the one to be used for the correction of the overlap of the analysis lines is determined based on the display. Depends on the correction method. First,
In the case of performing the overlap correction using the content of the interference component that generates the interference line, for example, if the influence IR of the overlap of the interference line Cr-Kβ1 with the analysis line Mn-Kα is equal to or greater than a predetermined value. The interference component Cr is retrieved and displayed as a component to be used for the overlap correction of the analysis line Mn-Kα.

Second, when the overlap correction is performed using the measured intensity of the fluorescent X-ray actually measured, for example, the analysis line M
Even if the degree of influence IR of the overlap of the disturbing lines Cr-Kβ1 with respect to n-Kα exceeds a predetermined value, the component Cr may be measured not by Cr-Kβ1, but by Cr-Kα. In such a case, Cr-Kα is retrieved and displayed as a fluorescent X-ray to be used for the overlap correction of the analysis line Mn-Kα instead. Third, in the case of performing the overlap correction using the theoretical intensity of the interference line, for example, assuming that the degree of influence IR of the overlap of the interference line Cr-Kβ1 with respect to the analysis line Mn-Kα becomes a predetermined value or more, Actually, even if Cr-Kβ1 is not measured, the measurement intensity is not necessary.
-Kβ1 is retrieved and displayed as a fluorescent X-ray to be used for the correction of the overlap of the analysis line Mn-Kα. In the second case, even when actually measuring a disturbance line in which the degree of influence IR of the overlap exceeds a predetermined value, if the wavelength of the disturbance line and the analysis line are almost the same, the disturbance line It is difficult to obtain the measured intensity of the same component (element)
Substitute other line types that can be measured for.

As described above, according to the method of this embodiment, based on the theoretical intensities Ii and Ij of the analysis line and the interference line calculated based on the composition information of the sample 13, the degree of influence of the overlap of the interference line Since IR is required with high reliability, it is possible to appropriately retrieve and display the fluorescent X-rays or components to be used for the overlap correction of the analysis lines. In addition, by determining and using the inter-order intensity ratio R _hi j, the degree of influence I of the overlap is appropriately considered not only for the primary line but also for a disturbing line which is a higher-order line of second or higher order.
Since R is obtained, the fluorescent X-ray or component to be used for the overlap correction of the analysis line can be more appropriately searched and displayed.
Further, by determining and using the escape peak intensity ratio, the degree of influence IR of the overlap is determined by properly considering the higher-order interference line including the escape peak, so that the fluorescence X to be used for the overlap correction of the analysis line is determined. Lines and components can be searched and displayed more appropriately.

In this embodiment, the application to the wavelength dispersive X-ray fluorescence analysis method has been described, but the present invention is also applicable to the energy dispersive X-ray fluorescence analysis method and apparatus. In that case, an escape peak is considered instead of a higher-order line, and the half width of the escape peak also corresponds to the energy.

[0040]

As described above in detail, according to the present invention, the degree of influence of the interference line is high based on the theoretical intensity of the analysis line and the interference line calculated based on the composition information of the sample. Since it is required with reliability, it is possible to appropriately search and display a fluorescent X-ray or a component to be used for the overlap correction of the analysis line.
Therefore, it is possible to quickly and appropriately perform the overlap correction based on the display.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an apparatus used for a fluorescent X-ray analysis method according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... X-ray source, 2 ... primary X-ray, 3 ... standard sample, 4 ... fluorescent X-ray generated from a sample, 5 ... spectroscopic element, 6 ... fluorescent X-ray separated by a spectroscopic element, 7 ... detector, 9 ... wave height analyzer, 10
... Detection means, 11 ... Search means, 12 ... Display means, 13 ...
sample.

Claims (6)

[Claims] 1. An X-ray fluorescence analysis method for measuring the intensity of X-ray fluorescence generated by irradiating a sample with primary X-rays from an X-ray source by a detection means, the method comprising the steps of: Based on the analysis lines, the theoretical intensities are calculated for the analysis line that is the fluorescent X-ray to be measured and the interference line that is the fluorescent X-ray that is in the vicinity of the analysis line within a predetermined wavelength range. Based on the theoretical intensity of the line, the intensity ratio of the interference line to the analysis line at the wavelength of the analysis line is determined as the degree of influence of the overlap, and the degree of influence of the overlap of each interference line is compared with a predetermined value. A fluorescent X-ray analysis method characterized by retrieving and displaying fluorescent X-rays to be used for overlap correction or components generating the same. 2. The method according to claim 1, wherein the detecting means is configured to split the fluorescent X-rays generated from the sample into a spectroscopic element, and to receive the fluorescent X-rays separated by the spectroscopic element according to the energy of the fluorescent X-rays. And a pulse height analyzer that selects a pulse within a predetermined wave height range among the pulses generated by the detector, and the light is separated by the spectroscopic element. The primary line is determined based on the theoretical intensity of the representative composition of the sample type to be analyzed, the peak height distribution curve by the peak height analyzer, and the predetermined range of the peak height for the disturbing line that is a secondary line or higher. X-ray fluorescence analysis method in which an intensity ratio of a higher-order line with respect to is determined as an inter-order intensity ratio, and the degree of influence of the overlap is obtained using the inter-order intensity ratio. 3. An escape peak intensity ratio according to claim 2, wherein an escape peak appearing in a wave height distribution curve of the wave height analyzer is determined in advance by an escape peak intensity ratio with respect to a disturbance line which is a higher-order line generating the escape peak. A fluorescent X-ray analysis method for determining the inter-order intensity ratio using the escape peak intensity ratio. 4. A fluorescent X-ray analyzer for irradiating a sample with primary X-rays from an X-ray source to measure the intensity of fluorescent X-rays generated by a detecting means, wherein a representative composition of a sample type to be analyzed is used. Based on the analysis line, which is the fluorescent X-ray to be measured, and the interference line, which is the fluorescent X-ray in the vicinity of the analysis line within a predetermined wavelength range, the theoretical intensity is calculated, and the analysis line and the interference are calculated. Based on the theoretical intensity of the line, determine the intensity ratio of the interference line to the analysis line at the wavelength of the analysis line as the degree of influence of the overlap, and by comparing the degree of influence of the overlap of each interference line with a predetermined value,
An X-ray fluorescence spectrometer comprising: a search unit for searching for a fluorescent X-ray to be used for the analysis line overlap correction or a component generating the X-ray; and a display unit for displaying a result searched by the search unit. . 5. The method according to claim 4, wherein the detecting unit is configured to split the fluorescent X-rays generated from the sample into a spectroscopic element, and to receive the fluorescent X-rays separated by the spectroscopic element according to the energy of the fluorescent X-rays. A detector that generates a number of pulses having the same wave height according to the intensity, and a wave height analyzer that selects pulses in a predetermined wave height range among the pulses generated by the detector. Regarding the disturbing line, which is a second-order or higher-order line that is separated by the element, based on the theoretical intensity of the representative composition of the sample type to be analyzed, the wave height distribution curve with the wave height analyzer, and a predetermined wave height range. An X-ray fluorescence analyzer for determining an intensity ratio of a higher-order line to a primary line as an inter-order intensity ratio, and using the inter-order intensity ratio to determine the degree of influence of the overlap. 6. The apparatus according to claim 5, wherein the search means escapes an intensity ratio of an escape peak, which is a higher-order line that generates an escape peak, with respect to an escape peak appearing in a wave height distribution curve of the wave height analyzer. An X-ray fluorescence analyzer that stores the peak intensity ratio and calculates the inter-order intensity ratio using the stored escape peak intensity ratio.