The speciation of arsenic compounds

It is known that arsenic demonstrates species-dependent toxicity. Quantification of elemental species in a sample, rather than determining total element levels alone, provides information that can be utilised in assessingtoxicity, bioavailability and potential effects on the environment. High performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) has proved an extremely efficient tool for identification and determination of arsenic species providing limits of detection at μg L - 1 levels. Low-pressure ion exchange chromatography using mini-columns can provide a simple, yet effective, method for rapid screening of samples. Inorganic forms of arsenic can be separated from organic forms within 3 min with limits ofdetection at 1.6 and 1.8 μg kg - 1 , respectively. The increasing use of electrospray techniques to provide structural information has enhanced the ability to distinguish with confidence previously unidentified species.