Influence of spectral characteristics of Cd and Fe elements in soil on laser-induced breakdown spectroscopy

摘要

In order to select more suitable characteristic lines as the analysis lines of the elements, laser-inducedbreakdown spectroscopy is used to detect the self-made soil sample doped with Cd and Fe elements. UsingSavitzky-Golay convolution smoothing method to preprocessed spectral data. Select the common line Cd I:288.122nm, 346.62 nm, Fe I: 357.001 nm, 363.146 nm to establish the calibration curve by externalstandard method, calculate the detection limit ， the influences of atomic configuration and angularmomentum on the calibration curve and detection limit of the spectral transition level are studied. Thestudy shows that the detection limit calculated by the analysis lines with high SNR are relatively low andmore sensitive to the detection of elements; The SNR of the analysis lines with the same atomicconfiguration of the transition show the same trend with the change of element content. The analytical linesCd I: 346.62 nm (2-1) and Fe I: 363.146 nm (4-3) with relatively large angular momentum are betterexcitation, and the correlation coefficient R2 of the obtained calibration curves are relatively higher, thelimit of detection is smaller than the Cd I: 288.122 nm (1-1) and Fe I: 357.001 nm (1-1), the lines with largeangular momentum are more suitable for element detection.