Ion Chromatography Method for the Determination of Trace Levels of Chromium(VI) in Water

Chromium exists usually in the (III) or (VI) oxidation states. In contrast to Cr(III), which is essential to mammalian systems, Cr(VI) is dangerous for humans due to its toxicity and carcinogenic properties. Cr(VI) compounds are highly soluble, mobile and bioavailable compared to Cr(III) species. Chromium is usually analyzed using instrumental methods such as AAS or ICP, which are accurate and sensitive, but allow determination of only the total content of chromium in a sample. Determination of Cr(VI) still represents a formidable challenge in analytical chemistry. This paper describes sensitive and selective determination of Cr(VI) in water samples on μg L-1 levels using an ion chromatography system with UV detector, without any sample preconcentration method. The detection limits achieved were less than 0.1 μg L-1 in deonized water and 0.2 μg L-1 in rainwater and drinking water, respectively. The method was applied to determination of Cr(VI) in rainwater and water extracts from galvanic sediments.