Speciation Analysis of Chromium in Environmental Samples

Chromium occurs in all compartments of the environment. Its wide range of natural sources determines the diversity of its forms of occurrence, which affect living organisms in a variety of ways. Chromium(II) has powerful reducing properties and forms colored complexes, chromium(III) is the most stable oxidation state, and chromium(VI) has strong oxidizing properties. Chromium(VI) compounds are considered the most toxic to humans and animals. Environmental contamination by chromium is assessed using analytical methodologies in which the key step is sample preparation, especially the use of appropriate techniques for extracting the various forms of chromium from samples prior to their quantitative determination.