Elimination of matrix effect and spectral interference by two compactly combined separations in the determination of Cd in geological samples with high Mo, Zr or Sn contents by ICP-MS

Abstract

The determination of Cd in geological samples with high Mo, Zr or Sn contents by ICP-MS suffered from matrix effects and severe spectral interferences. In this work solvent and solid phase extractions (SPE) were combined and both matrix and spectral interference free determinations were realized. After solvent extraction with an acidic extractant, interferences from Sn and Zr were reduced over 1000 fold, and Mo about 250 fold, while matrix elements could be effectively removed by a SPE column. A linear working curve could be obtained between Cd concentrations of 0.2–20 μg L⁻¹, with a correlation coefficient of 0.9992. Cd recoveries in both separation systems were shown to be near 100%, and a total enrichment factor could reach 22. Feasibility of the established method was demonstrated by analyzing three soil geological standard reference materials with high Mo, Zr or Sn contents. The results showed that the established method was accurate, fast, low in procedural blank value, and good in Cd recovery.