Determination of platinum,palladium,rhodium and iridium in mineral samples by Zeeman graphite furnace atomic absorption spectrometry after the preconcentration with lead fire assaying

A novel method for determining platinum palladium,rhodium and irdium in mineral sample was established using Zeeman graphite furnace atomic absorption spectrometry.Mineral sample was melten using traditional lead fire assaying,and platinum,palladium,rhodium and irdium was accumulated in 3 mg of lead by cupellation.This alloy was dissolved in HNO3,and then HCl was added to form aqua regia solution to make sure that platinum,palladium,rhodium and irdium were fully dissolved in this solution.The concentration of the above four elements was detected at the selected instrumental parameters using Zeeman graphite furnace atomic absorption spectrometry.A calibration curve was created based on linear least squares fitting technique with a satisfactory curve fitting effect.The standard correlation coefficients are 0.999 9,0.999 9,0.999 2 and 0.999 4,and the characteristic concentration is 1.854 2 ng/mL,1.543 5 ng/mL,0.488 3 ng/mL,and 0.481 1 ng/mL for platinum,palladium,rhodium and irdium,respectively.The relative standard deviations(n=4) are 1.5%-4.5%(Pt),1.1%-2.9%(Pd),3.4%-6.3%(Rh),2.9%-5.8%(Ir).The concentration of platinum,palladium,rhodium and irdium of standards material detected by this method is consistent with the certified value.