A high-precision quantitative analysis method of laser-induced breakdown spectroscopy

Abstract

The invention provides a high-accuracy quantitative analysis method of laser induced breakdown spectrum. The method includes: using a laser induced breakdown spectrum system to measure different positions of each sample for N times, acquiring original data of N spectra for each sample, and taking the N spectra as a group; repeatedly measuring each sample for M times to acquire M spectrum originaldata; preprocessing the M spectrum original data; respectively extracting intensity of tested element characteristic spectral line in the N spectra in M spectra of each sample, and calculating to acquire mean value, variance and relative standard deviation of M data of each sample; utilizing a significance testing method to screen the M data of each sample, summing all spectrum data of the rest groups after screening, and averaging to acquire final spectrum data; using the final spectrum data of all samples to build a quantitative analysis model. By the method, reproducibility and quantitativeanalysis accuracy of LIBS measuring results can be remarkably improved.

Description

technical field [0001] The invention relates to a quantitative analysis method in the technical field of detection, in particular to a high-precision quantitative analysis method of laser-induced breakdown spectrum. Background technique [0002] Laser-induced breakdown spectroscopy is an analytical method that uses plasma emission spectroscopy to analyze the composition and content of material elements. The laser is focused on the surface of the object, and the material is ablated into plasma. By analyzing the spectrum emitted by the plasma, the element type of the object to be measured can be qualitatively determined and its content can be quantified. Due to the complex coupling mechanism between the laser and the measured substance, the evolution of the plasma is affected by many factors, resulting in poor repeatability of measurement results and low accuracy of quantitative analysis. [0003] In laboratory applications, sophisticated, high-cost experimental devices and c...

AI Technical Summary

Problems solved by technology

However, in the actual field application of LIBS, especially when the relative standard deviation of spectral line intensity reaches 20% to 50%, even if multiple groups of measurements are carried out, and each group is measured hundreds of times, the difference between the mean values ​​of the groups is still possible. significant difference

The mean of each group may still deviate greatly from the true value, and iterative use of Raida's criterion will cause the data to move further towards the wrong mean instead of eliminating this deviation

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