A quick method to determine the impurity content in gold ornaments by LIBS technique

Abstract

Laser induced breakdown spectroscopy (LIBS) and low energy dispersive X-ray fluorescence (ED-XRF) spectrometer, were used to determine the line intensity and concentration ratios of the major impurities (Cu and Ag) with respect to Au in gold ornaments with different caratage. Calibration curves were drawn with the data sets, obtained from LIBS and XRF, and from these calibration curves the unknown caratage of gold ornaments were obtained by using the line intensity of elements determined by LIBS. We have demonstrated the accuracy of this method by comparing the result with the carat value obtained by typical XRF method. This is yet another novel application of LIBS as a versatile analytic technique.