Application of Laser Induced Breakdown Spectroscopy as an Alternative Method for Identification of Quality of Gold Alloys

Abstract

In this study a robust and alternative method of gold quality identification is presented. Four different Karats of gold from different origins were used for investigation. Comparison was made between the traditional Quantum Karat meter and Laser Induced Breakdown spectra to compare their quality. The advantage of the new technique over the Karat meter is that the different types of impurities that are found in the gold were clearly identified and their quantities/percentage tabulated. The method is also robust in such a way that it is calibration free. During the experiment, the most resonant atomic line and ionic line of emission of gold were taken at 267.597 nm and at 226.363nm, respectively, in order to reduce the impact of the back ground on the spectral intensities. The experimental result indicated that both atomic and ionic lines of emission were found in very good agreement with Quantum Karat meter and can reliably be applied as an alternative method of quality control or in a place where such equipment is not available. It was found that the ionic to background and atomic to back ground ratios as well as their normalized intensities were in excellent match with the results from the measured quantum Karat meter.