Arsenic speciation in water by hydride cold trapping-quartz furnace atomic absorption spectrometry: an evaluation

Abstract

Arsenate, arsenite, monomethylarsonate, monoethylarsonate and dimethylarsinate are speciated in environmental waters. After pH-dependent hydride generation, the arsines are collected on a cold trap and volatilised sequentially into a quartz furnace atomic absorption spectrometer.The various parameters of the methodology are optimised, and their influence critically discussed and compared with other methods. Aspects such as interferences in organoarsenic speciation, the effect of atomisation support gases in collection mode techniques and unambiguous identification of dimethylarsine are emphasised in particular. An evaluation of the analytical characteristics and performance of the method is presented, using representative environmental samples. This paper attempts to illustrate the advantages and drawbacks of the technique and includes a review of recent progress in arsenic hydride methodology.