Determination of platinum and palladium in geochemical samples by low Pb fire assay enrichment-inductively coupled plasma mass spectrometry……Mao Ying,Zhu Kun,Zou Guangfu

Abstract：The paper establishes a method of fire assay-inductively coupled plasma mass spectrometry(ICP-MS) for the determination of platinum and palladium in geochemical samples.The method uses the fire assay (7-11 g assay button) instead of classical lead assay (40 g assay button) and basic lead carbonate instead of toxic carbonyl nickel,adds the protective agent of silver nitrate,making the elements to be detected in lead button enter silver alloy without loss after ash blowing and the interference elements further separated,and carries out the determination of platinum and palladium by inductively coupled plasma mass spectrometry.The detection limits of platinum and palladium are 0.10 ng/g and 0.12 ng/g respectively.The recoveries of standard materials are 92.50 %-106.75%,and the relative standard deviations (RSD)are 2.35 %-6.44 %,and the accuracy and precision meet the requirements.The method has high sensitivity and is easy to operate with accurate results,which makes it suitable for the analysis of large-scale geochemicalsamples,especially in the detection of trace precious metals.

Keywords:low Pb fire assay enrichment; inductively coupled plasma mass spectrometry; geochemical samples; platinum; palladium