JP3609034B2 - Elemental analysis method and characteristic analysis program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of irradiating a sample with an ion beam emitted from an accelerator, detecting X-rays generated from the sample, and performing quantitative elemental analysis of the sample from its spectrum, and a computer program used therefor, particularly in a local area. Analyze the data based on the characteristics of the installed equipment and the installation environment with the central equipment, check the analysis data for problems in human analysis work, guide and manage that know-how, Reliability is improved.
[0002]
[Prior art]
Conventionally, an analyzer using an elemental analysis method called a particle induced X-ray emission (Particle Induced X-ray Emission) is known. This device generates X-rays (characteristic X-rays) having energy specific to the elements contained in the sample by irradiating the sample to be analyzed with a high-energy ion beam such as protons, alpha particles, and heavy ions. The characteristic X-ray is measured with an X-ray detector, and the element in the sample is analyzed from the X-ray spectrum.
When elemental analysis is performed by this analyzer, the sample set in the apparatus is preferably an extremely thin film in order to prevent self-absorption of X-rays and perform quantitative analysis with high accuracy. Pretreatment such as fine powdering, dilution with a solvent, or chemically weakening of viscosity is performed. In order to use as a calculation standard for quantification, a specific amount of a specific element that is not contained in the sample is mixed as an internal standard element. Therefore, if the components are not average, stir the sample well, or if it is an ecological sample, perform decomposition treatment such as nitrate ashing.
[0003]
[Problems to be solved by the invention]
When performing an analysis using the above-described conventional analyzer, the processing for sample preparation is a precise operation, so technical skill is required, and if there are variations in the method of adjustment, the analysis results will vary. The reliability of analysis results is impaired.
For example, it is desirable that the thickness of the sample after being mounted on the backing film, fixed, and dried is desirably about several μm on average throughout, and if this varies, the X-rays are absorbed by the sample and the quantitative value is deviated. In particular, this phenomenon becomes prominent when the thickness of the sample is 10 μm or more. Even if the islands vary, the analysis results are affected. In addition, when preparing a sample by treating the object to be measured with an acid, it contains elements that are likely to volatilize due to the Ph of the solution, or has an unfavorable affinity with the chemical used in the solvent, causing aggregation and analysis. If the sample to be used is extremely small, the element distribution will fluctuate, and if the adjustment method for the measurement target is selected incorrectly, accurate analysis cannot be performed. In addition, if processing is performed such as drying the sample depending on the work environment or internal standard elements are added, elements that are not originally contained will be mixed in, and the element detection results and content values will be reduced. It will be different. Thus, the operator who prepares the sample must have special skill and knowledge, and also requires specialized chemistry, especially analytical chemistry expertise.
In the PIXE analysis, appropriate setting elements such as the distance from the sample surface to the X-ray detector, the intensity of the ion beam, and the selection of the X-ray absorber must be selected in accordance with the state of the sample and the contained elements. As a result, detection sensitivity can be increased, measurement time can be shortened, conversely, analysis sensitivity can be adversely affected by the generation of γ rays, and the trace element spectrum cannot be detected because it is hidden behind the main element spectrum. There is. In addition, the distance from the sample surface to the X-ray detector and the intensity of the ion beam must be kept strictly constant, and if these change, the quantitative analysis results also change. The X-ray absorber (X-ray filter) adjusts the X-ray dose to be detected depending on the composition and thickness. Therefore, if it is placed in front of the detector, it will affect the detection sensitivity of X-rays. Problems such as a case where a specific element is not detected or a trace component is not detected occur.
Furthermore, since the computer program for executing the analysis work by the analyzer includes a spectrum creation program that represents the detection result of the detector in an X-ray spectrum and an X-ray spectrum analysis program, the computer program and the analysis method In addition to the above knowledge, physical knowledge regarding the generation and absorption of X-rays and γ-rays, and specialized knowledge such as the mechanism of the measuring apparatus are required.
In this way, PIXE analysis requires an analysis worker with skilled skills and knowledge, but assigning workers to each analysis center where the device is installed is inefficient and limits the range of use of the analysis device. It will narrow.
Therefore, the present invention eliminates analysis errors based on the characteristics of the apparatus to be analyzed and the sample adjustment of the measurement object, and performs elemental analysis with high accuracy. An object of the present invention is to provide an economical elemental analysis method and a computer program used therefor, which are intended to expand the utilization of analytical devices by effectively utilizing resources.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, in the first invention, the sample beam S is irradiated with the ion beam B from the ion accelerator 6, X-ray R generated from the sample S is detected, and elemental analysis is performed based on the X-ray spectrum. In the elemental analysis method to be performed, X-ray spectrum data is sent from the local analysis center 2 to the central analysis technology center 1 through the network 3, and the central analysis technology center 1 performs quantitative analysis of the component elements from the data.
In the second invention, the ion beam B from the ion accelerator 6 is irradiated onto the sample S, the X-ray R generated from the sample S is detected by the X-ray detector 9, and the constituent elements are quantified from the X-ray spectrum. Elemental analysis method for analysis, wherein X-ray spectrum analysis data is sent from a local analysis center 2 that has collected the data to a central analysis technology center 1 through a network 3. By comparing the data related to the check sample with known data, the characteristic unique to the X-ray detector 9 is found, and this characteristic is reflected in the analysis of the data related to the sample to be measured, and the component elements are quantitatively analyzed. .
In the third invention, the central analysis technology center 1 analyzes the data and then sends the analysis result to the analysis center 2 through the network 3.
In the fourth aspect of the invention, a characteristic element unique to the X-ray detector 9 is found from an error from known data relating to the check sample, and this characteristic element is X of a computer that quantitatively analyzes the component element from the X-ray spectrum data. A computer characteristic analysis program was built into the line spectrum analysis program to analyze the analysis data without error.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a network, and FIG. 2 is a schematic configuration diagram of an analyzer.
[0006]
In FIG. 1, a single central analysis technology center 1 and analysis centers 2 provided at a plurality of locations distant from the center are each provided with an analysis device 4, both of which are connected via a network 3, so Information can be exchanged. The network 3 may use the Internet or may be a dedicated communication line network that is uniquely constructed.
[0007]
As shown in FIG. 2, the analysis device 4 includes an ion accelerator 6 having an ion generator 5 inside. The ion accelerator 6 communicates with a beam introduction tube 7 for introducing an ion beam B. At the end of the beam introduction tube 7, a vacuum chamber 8 that covers the sample S inside is provided. By irradiating the sample S in the vacuum chamber 8 with the ion beam B, X-rays (characteristic X-rays) R having energy specific to the elements contained in the sample S are generated, and the characteristic X-rays R are detected. An X-ray detector 9 is facing. Connected to the X-ray detector 9 is an X-ray separation device 10 including an amplifier that amplifies a weak electrical detection signal output from the X-ray detector 9. The X-ray separator 10 separates the characteristic X-ray R for each element. The computer 11 connected to the X-ray separation apparatus 10 includes an X-ray spectrum creation program 11a. The characteristic X-ray R separated for each element by the X-ray separation apparatus 10 is made into data based on the X-ray spectrum and displayed on the screen. The data is recorded, printed out as necessary, and this type of data is transmitted and received via the network 3.
[0008]
The computer 12 of the central analysis technology center 1 is provided with an X-ray spectrum analysis program 13. The X-ray spectrum analysis program 13 identifies an element from the position of a peak on the spectrum based on the X-ray spectrum data, and displays the characteristic X-ray R of each element as noise (back) of other X-rays that appear on the spectrum. The computer 12 is caused to execute processing for separating the ground and determining its content. The computer 12 can transmit and receive data via the network 3. The computer 12 includes a characteristic analysis program 14 and a sample adjustment check program 15 in addition to the X-ray spectrum analysis program 13. The characteristic analysis program 14 analyzes the check sample with the X-ray detector 9, and from the data of the X-ray spectrum, the circuit system including the X-ray detector 9 and the X-ray separation device 10 associated therewith is analyzed. Find characteristics. The characteristic analysis program 14 analyzes the characteristics of the detectors 9 and 9 having the same type and the same specification because the characteristics are different from each other. Further, the characteristic analysis program 14 creates a physical model of the characteristic for each detector 9 from the analyzed characteristic, and incorporates it into the X-ray spectrum analysis program 13 to reflect the subsequent X-ray spectrum analysis appropriately. When characteristic X-rays are measured using the same energy X-rays with the same settings, peaks appear at substantially the same position, but adjustment is not possible depending on the state of the X-ray detector 9 and the associated circuit system at the time of measurement. In order to correct subtle differences in characteristics in the subsequent spectral analysis work, the measured X-ray spectrum itself is used to perform strict energy calibration of the X-ray spectrum, and the previously created physical model is By applying and incorporating it into the X-ray spectrum analysis program 13, the characteristics of the X-ray detector 9 including the accompanying circuit are reflected as an appropriate state.
[0009]
The sample adjustment check program 15 performs sample adjustment and analysis on the check sample in the central analysis center 1 and the local analysis center 2 respectively, compares the X-ray spectrum with the quantitative analysis results, and performs statistical processing. This is a program that examines and identifies whether there is an analysis hindrance factor at the analysis center. For example, the deterioration of the detector, energy adjustment to prevent discharge at the electrostatic accelerator, erroneous setting of the detection circuit by the worker, noise (background) contamination due to various causes, etc. Included are those that are caused by, and those that are caused by improper sample preparation before measurement.
[0010]
In each local analysis center 2, a sample is prepared from an analysis object that has been requested by a customer, and elemental analysis is performed by the analyzer 4 as described above. That is, the characteristic X-ray R generated from the sample S is captured by the X-ray detector 9, converted into an electric signal, amplified in the X-ray separator 10 and subjected to signal shaping to separate the characteristic X-ray R for each element, Create and record X-ray spectrum data. This data is sent to the central analysis technology center 1 through the network 3. At the same time, the central analysis technology center 1 receives data related to the check sample whose component elements are known by the analysis device 4 of the analysis center 2. The central analysis technology center 1 analyzes the characteristics of the detector 9 and the like of the analyzer 4 from the X-ray spectrum data relating to the check sample, and the physical model of the characteristics is analyzed by the X-ray spectrum analysis program 13 in the central analysis technology center 1. Quantitative analysis of component elements. The analysis result is sent to the analysis center 2 through the network 3, and the analysis center 2 reports the result to the customer.
[0011]
In addition to analyzing the above data, the Central Analysis Technology Center 1 includes sample adjustments to the Analysis Center 2 such as sample pretreatment, table setting, and special measures for trace elements. It provides technical support by instructing how to handle samples and knowing how to operate the equipment. Therefore, since the analysis center 2 can perform elemental analysis at least if it learns the operation of the analyzer and sample preparation, it becomes easy to use the analyzer. Furthermore, the Central Analysis Technology Center 1 performs software or hardware improvements and developments on the analysis device including analysis programs and related programs.
[0012]
In the present embodiment, a so-called vacuum PIXE apparatus in which a chamber is provided and the inside is evacuated is used. However, the present invention is not limited to this, and a sample is placed in a specific gas atmosphere without providing a chamber. Alternatively, a so-called atmospheric PIXE apparatus placed in the atmosphere may be used.
[0013]
【The invention's effect】
As described above, in the present invention, it is possible to check and correct the adjustment of the sample set in the apparatus and to analyze the analysis data uniformly with high accuracy even if it is a trace element. Reliability for elemental analysis can be improved. Special skill, know-how and knowledge necessary for analysis can be concentrated in the Central Analysis Technology Center, which can simplify the analysis work in the analysis center in the region, Intellectual resources can be used effectively, and the use of analyzers can be expanded.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a network used in an elemental analysis method according to the present invention.
FIG. 2 is a schematic configuration diagram of an analyzer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Central analysis technology center 2 Analysis center 3 Network 4 Analyzer 5 Ion generator 6 Ion accelerator 8 Chamber 9 X-ray detector 10 X-ray separator 11 Computer 11a X-ray spectrum preparation program 12 Computer 13 X-ray spectrum analysis program 14 Characteristic Analysis program 15 Sample adjustment check program S Sample

Claims (3)

An element analysis method for irradiating a sample to be measured with an ion beam from an ion accelerator, detecting X-rays generated from the sample with an X-ray detector, and quantitatively analyzing component elements from an X-ray spectrum,
Send the X-ray spectrum data from the local analysis center that collected the data to the Central Analysis Technology Center through the network.
At the Central Analysis Technology Center, the data related to the sample for checking at the analysis center is compared with known data to find the characteristic unique to the X-ray detector, and this characteristic is reflected in the analysis of the data related to the sample to be measured. Elemental analysis method characterized by quantitative analysis of elements. The elemental analysis method according to claim 1, wherein the central analysis technology center analyzes the data and sends an analysis result to the analysis center through a network. A characteristic element unique to the X-ray detector is found from an error from known data relating to the check sample, and this characteristic element is incorporated into an X-ray spectrum analysis program of a computer that quantitatively analyzes component elements from the X-ray spectrum data. A computer characteristic analysis program used in the elemental analysis method according to claim 1, wherein the analysis data is analyzed without error.

Images