Partial least squares regression for problem solving in precious metal analysis by laser induced breakdown spectrometry

The application of laser induced breakdown spectrometry for the quantitative determination of gold and silver in Au–Ag–Cu alloys is proposed. Laser induced plasma emission spectra in the ultraviolet region were studied in order to characterize the spectral information from time-integrated data. The multivariate calibration method known as partial least squares regression type 1 was used for calibration and prediction purposes. Satisfactory results were obtained for the determination of gold and silver without temporal resolution strategies. Since the employment of this chemometric algorithm was a good alternative for simplification of the experimental setup, a rapid, simple and low cost method is thus proposed for the determination of noble metals in jewelry pieces.