Application of a metal free high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the determination of chromium species in drinking and tap water

In some environmental and occupational setting, determination of total chromium is inadequate fora complete toxicological evaluation and risk assessment because the toxicity and bioavailability ofchromium depend upon the form or species.In this study, trivalent and hexavalent chromium compounds were determined by high performanceliquid chromatography with inductively coupled plasma mass spectrometry (HPLC–ICP-MS) equippedwith dynamic reaction cells (DRCs) and a reversed-phase C8 column. All the instruments and deviceswere metal free, thus avoiding any interference caused by leaching from metallic components.The mobile phase (EDTA2(Na) 5 mM pH 7, 40◦C) directly forms a complex with the Cr(III) in the pre-heated, allowing a single chromatographic method to be used to separate the Cr(III) EDTA complex andthe Cr(VI).This analytical method was applied in several samples of mineral and tap water with the aim todetermine a different ratio of Cr(III) and Cr(VI).In tap waters Cr(VI), ranged from 10.88 to 0.1 _g/L while Cr(III) ranged from 0.33 to 0.1 _g/L.The highest levels of Cr(VI) were measured in Brescia, a highly industrialized province in northern Italyin which high levels of Cr(VI) have been a public health concern.In commercial mineral waters, the range of Cr(III) and Cr(VI) were 0.11–0.80 _g/L and 0.25–3.4 _g/L,respectively. The method applied in this study is a rapid, sensitive (LOD 0.1 _g/L) and specific technique for determination of chromium species in water.