On-site separation of arsenic species using a sorbent C18 column modified with APDC followed by ICP-MS determination

Abstract

The separation of unchanged As(III) species, just after sampling, is crucial for reliable speciation analysis of that element in water systems. In the presented paper, a simple and quick procedure is described for As(III) separation from a water matrix on the sampling site, integrated with speciation analysis using ICP-MS. For the separation of As(III) anions, a C18 column was saturated with APDC. The acidification of the water sample to pH 2 ensured 100% retention of As(III) anions and effective separation from As(V), MMA and DMA. C18 columns modified with APDC can be prepared and stored in the laboratory for up to 24 hours before use on the sampling site. The influence of Pb, Cd, Tl, and Cr cations can be limited with the addition of EDTA. Anions such as SO₄²⁻ and PO₄³⁻ do not significantly affect the efficiency of As(III) anion retention.