Quantitative analysis of bronze samples by laser-induced breakdown spectroscopy (LIBS): A new approach, model, and experiment

A new approach to the quantitative elemental analysis of alloys by means of laser-induced breakdown spectroscopy (LIBS) is proposed. The disproportion between the element stoichiometry and spectral intensities is attributed to selective evaporation of components during the heating-melting-evaporation stage. The proposed correction to plasma spectra with account for the Prokhorov-Bunkin melt transparency wave ensures a good agreement between the relative intensities of LIBS analytical lines [(nm): Cu, 511; Zn, 472; Sn, 286; Pb, 406] and the alloy stoichiometry for five samples of four-component bronze measured in various regimes of plasma excitation and signal detection. A criterion is formulated to select the analytical lines, for which the concentration of elements is proportional to the constant of the process and the intensity of the corrected lines.