Method of improving precision of quantitative analysis of overlapping peak of laser induced breakdown spectrometry

Abstract

The invention discloses a method of improving the precision of quantitative analysis of an overlapping peak of laser induced breakdown spectrometry. The method comprises the following steps: detecting a calibrated sample with known element content by means of an LIBS technology to obtain a spectrogram of the calibrated sample; then correcting overlapping interference and continuous background interference by means of integral strength combined with small wave transformation, establishing a univariate linear regression model by separately taking the corrected characteristic spectral line integral strength and the content of analysis element as an independent variable and a dependent variable, and optimizing integral region factors w1 and w2, an overlapping interference factor alpha, a decomposing layer number l, and a wavelet function and continuous background deduction scale factor gamma according to a root-mean-square error of the calibrated sample; and finally, correcting the spectrum of a to-be-detected sample by employing the optimized parameters of the corresponding calibrated sample, and predicting the content of the analysis element in the to-be-detected sample by means of the univariate linear regression model. The method disclosed by the invention can remove interference of overlapping and continuous background on the spectral line, so that the precision of quantitative analysis of the overlapping peak in a complicated sample of a base body can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of material component detection, and more specifically relates to a method for improving the quantitative analysis accuracy of laser-induced breakdown spectrum overlapping peaks. Background technique [0002] Laser Induced Breakdown Spectroscopy (LIBS for short) focuses a high-energy-density pulsed laser on the surface of the substance to be measured, ablates it to generate a high-temperature plasma, and then determines the measured substance by collecting and analyzing the emission spectrum in the plasma. Material composition analysis technology for the composition and content of each element in a substance. Due to the advantages of fast speed, no sample preparation, multi-element, long-distance and online simultaneous detection, LIBS technology has broad application prospects in many fields such as industrial production, environmental monitoring, biomedicine and space exploration. [0003] However, the ma...

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Problems solved by technology

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a method for improving the quantitative analysis accuracy of laser-induced breakdown spectrum overlapping peaks, which uses the optimized integral area factor W obtained from the corresponding calibration sample 1 and W 2 , overlapping interference factor α opt , decomposition layer number L, wavelet function F and continuous background subtraction scaling factor γ opt Correct the spectrum, and finally use the univariate linear regression model to predict the content of the analytical elements in the sample to be tested, which can effectively solve the existing problems of quantitative analysis accuracy of overlapping peaks caused by the low accuracy of overlapping peak decomposition and the inability to accurately remove continuous background interference. It has the advantages of convenient and accurate analysis, and is suitable for occasions such as quantitative analysis of overlapping peaks of materials with complex matrices, especially steel, plastic, and petroleum.

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