Abstract
A procedure for matrix effect reduction is proposed to enhance the precision of quantitative analysis of metal alloys using laser-induced breakdown spectroscopy (LIBS). This procedure is based on a number of successive steps in order to correct the signal fluctuations caused by plasma interaction and the matrix effect. The first step is the selection of optimum parameter settings of the detection system, such as laser power, delay time, and focal distance. The second step is the estimation of the absolute or relative values of impurities on the basis of the internal standard calibration. The third step is the analysis of the metal basis of the alloy used as an internal standard, which requires spectrum averaging, whole integral spectrum normalization, and self-absorption correction. Three sets of metal-based alloys (aluminum, steel, and copper) are used in this investigation as reference standards for calibration and validation. Successive improvements of the quality of calibration curves are observed during the proposed procedure.