Evaluation of Methods for Quantifying Cr (VI) and Cr (III) in Soils and Wastes

Accurate measurement of Cr species in non-aqueous media such as soils and sediments is complicated by chemical processes that can alter the indigenous amounts of Cr (III), a micronutrient, and Cr (VI), a known carcinogen. The accurate determination of Cr (VI) is critical in order to make informed decisions about remedial actions and to assess the health and safety of the public. For soils or sediments without significant amounts of certain organics, metals or anions, Cr (VI) can be measured with a high degree of accuracy. However, many soils and/or sediments with matrix components including those listed above can oxidize a laboratory spike of Cr(III) species to Cr(VI) species [resulting in the over-reporting the true amount of Cr(VI)], or reduce a laboratory spike of Cr(VI) to Cr(III) [resulting in the under-reporting the true amount of Cr(VI)].SR06-051R. Lee Lippincott is the NJDEP project manage