Abstract：The sample was dissolved in hydrochloric acid and separated with cation exchange resin. After the solution was concentrated by evaporation,trace lead in high purity indium was determined by graphite furnace atomic absorption spectrometry. The optimum conditions for sample dissolution,ion-exchange separation and determination of lead were investigated. It was indicated that 1 g of indium could be dissolved with 8 mL of hydrochloric acid. Trace silver,arsenic,cadmium,silicon and most of indium in the sample could be separated and removed after ion-exchange with 0.5 mol/L hydrochloric acid as leacheate. Then,lead could be eluted with 2.0 mol/L hydrochloric acid. Although aluminium,copper,iron,magnesium,nickel,tin,thallium,zinc and less than 10 μg indium could not be separated from lead,they had no influence on the determination. With sample dosage as 1 g,diluted volume as 1.0 mL and sample volume as 50 μL,the linear range of this method was 0.5-4.0 ng/mL,and the limit of quantitation was 0.000 6 μg/g,which was lower than that of industry standard method YS/T230.1-1994 (0.1 μg/g) by three orders of magnitude. The proposed method was applied to the analysis of actual sample,and the results were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS). The relative standard deviations (RSD,n=8)was 1.1%-19.7%,and the recoveries were 92%-120%.
