Speciation of inorganic arsenic and selenium in contaminated ground water samples - distribution and long-term stability of species

This paper presents the results of speciation studies of arsenic and selenium in contaminated ground water samples from Kelheim/Germany. Results are based on separation of ions by HPLC using a phosphate buffer. The separated species were collected in fractions and analysed element-specifically by HG- AAS. Dominating species were arsenate and selenate, while arsenite and selenite were less important. Long-term studies revealed that As (V), Se (IV) and Se (VI) remained stable for up to 12 months, whereas oxidation of As (III) was observed after 3 months