A fast and accurate method for the determination of precious alloys caratage by Laser Induced Plasma Spectroscopy

The purpose of this paper is to present a new and efficient technique for precious alloys caratage based on the Laser Induced Plasma Spectroscopy (LIPS) method. The LIPS analysis can be carried out in few minutes and in an essentially non-destructive way on samples of arbitrary shape. Experimental results showing the feasibility of the method for fast and precise analysis of gold jewellery without the need of calibration are presented. Using a new technique of LIPS spectra analysis, recently developed and patented by the Applied Laser Spectroscopy Laboratory at IFAM, we were able to obtain quantitive information about all the alloy components, including trace elements at concentration down to the order of 1 ppm. Matrix effects do not affect the accuracy of the technique.