Studies on the determination of trace elements in high-purity Sb using GFAAS and ICP-QMS

摘要

Trace element impurities in high-purity antimony were determined employing three different methods for the removal of matrix; on Dowex 50WX 8 by adsorption from 0.1 mol/L HF and elution with 4 mol/L HNO_3; on Chelex-100 resin (in NH_4~+ form) Bi, Cd, Co, Cu, and Pb were separated in the presence of tartaric acid at a pH of 9.0 +- 0.1 with subsequent elution with 2 mol/L HCl; these determinations were carried out by GFAAS. The separation of trace impurities from Sy by volatilization of the matrix from H_2SO_4 and HBr medium was also investigated. ICP-MS was used for the determination in these cases. All the three procedures showed that the removal of the antimony matrix was nearly quantitative (> 99.99%). The recoveries of trace elements were found to be > 95%. The relative standard deviations were in the range 2-7%. Standard addition calibrations were used. The levels of process blanks indicate that with careful optimization, the volatilization procedure coupled with ICP-QMS can be used for trace impurity characterization of 6N + Sb.