Quantitative analysis of Pb in soil samples by laser-induced breakdown spectroscopy with a simplified standard addition method

A simplified standard addition method (SAM) was proposed for the quantitative analysis of Pb in solid soil samples by laser-induced breakdown spectroscopy. Principal component analysis (PCA) was used to cluster spectral datasets of seven soil samples which were extracted from seven sites in the vicinity of the Northwest China Lead-Zinc Smelter to distinguish component differences of matrices. It was found that the matrices of the samples at each sampling site were different, and thereafter matrix-matched samples were prepared using the SAM. To verify the validity of the SAM, calibration curves were established for all samples. The results show that the concentrations of Pb can be quickly obtained by the SAM while the additional concentrations were selected from the calibration curves. Moreover, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used to assess the accuracy of the results. This study shows that the SAM is a fast method for the quantitative analysis of elements in solid soil. Additionally, the detection limits were calculated from the calibration curves.