A multi-energy calibration method was applied for the determination of chromium and nickel in nickeliferous ores by laser-induced breakdown spectroscopy. For the optimization of the laser-induced breakdown spectroscopy parameters, such as laser fluence and delay time, an experimental study was conducted. The best results in terms of trueness were observed using a laser fluence and a delay time of 2500 J/cm2 and 1.1 μs, respectively. A study of sample matrix effects and the determination of emission lines for calibration and normalization of the spectra were undertaken, and appropriate values of those variables were selected for each analyte. The trueness values for chromium and nickel varied from 89 to 114% when certified reference samples (nickeliferous laterite, rock phosphate and contaminated soil) were analyzed.
Keywords: LIBS; MEC; calibration; chromium; minerals; nickel; ores.