Analysis of Chromium in Waters Using Voltammetry

摘要

Chromium can make its way into different water sources from a variety of outlets and historically chromium has been measured using spectroscopic or colorimetric techniques. Chromium enters the different water supplies via discharges from industries, leaching from hazardous waste sites or naturally from the erosion of natural deposits. Two distinct forms of chromium occur in these water sources; the non-toxic trivalent chromium (Ⅲ) an essential trace nutrient and hexavalent chromium (Ⅵ), a toxic species that can cause great harm to individuals and the surrounding environment The toxicity of chromium (Ⅵ) serves as the basis of setting the (total) chromium standard for drinking water currently 50μg l~(-1) in the United Kingdom. With voltammetry one also has the option to speciate between the two chromium species, but usually chromium (Ⅵ) is the reported analysis due to its environmental and health impact. Over recent years, voltammetry has undergone a tremendous surge in popularity and today represents a refined, clean simple technique that offers outstanding limits of detection and is now the fastest growing analytical technique for trace analysis being eminently suited to chromium analysis. The nature of the water sample being quantified does not restrict the voltammetric analysis, it makes little difference (other than sample preparation) as to whether the samples are potable, effluent or saline in nature.