Arsenic speciation in soil-pore waters from mineralized and unmineralized areas of south-west England

Arsenale, arsenite and monomethylarsonic acid (MMAA) have been characterized in soil-pore waters extracted from soils in mineralized and unmineralized areas. Special attention has been paid to collection and storage of the samples. The dominant arsenic species in aerobic soils was arsenate, with small quantities of arsenite and MMAA in mineralized areas. In anaerobic soils arsenite was found to be the major soluble species. The analysis was done with an HPLC anion-exchange column combined with continuous-flow hydride-generation and atomic-absorption spectrometry. A preconcentration column was incorporated to increase the sensitivity.