Comparison of Detection Methods for Gold Content in Gold Jewelry

At present, testing methods for gold content in gold jewelry are mainly fire assaying method, X ray fluorescence(XRF) and inductively coupled plasma-atomic emission spectrometry(ICP-AES). When there are disagreements in the testing results, fire assaying method is the arbitral method. In this paper, the gold contents of 14K, 18K and 22K gold samples were determined by the three different methods, and the results were compared and analyzed. The results showed that, under the conditions that the three methods met the accuracy requirement of sample analysis, and using the fire assaying method as the criterion, then the relative errors were quite different in the results of determing the same purity of gold by XRF and ICP-AES. The results of the XRF method can meet the testing requirements, while that of the ICP-AES method can not. The relative error of XRF method was 0.05%~0.77%, and that of the ICP-AES method was 1.24%~3.89%. From the results, the test results of low purity precious metal jewelry using XRF method were closer to the fire assay method.