Determination of Hexavalent Chromium (Cr+6) by USEPA 218.7

Chromium exists in the environment in two basic forms including trivalent chromium (Cr+3) and hexavalent chromium (Cr+6). While Cr+3 is a beneficial nutrient to humans, significant study into the detrimental effects of Cr+6 in humans has labeled hexavalent chromium as carcinogenic. The EPA’s new federal mandate, in addition to growing public concern over Cr+6, is now persuading municipal water systems to monitor Cr+6 down to sub-parts-per-billion (ppb) levels. Use of ion chromatography (IC) coupled with post column reaction and UV detection is demonstrated according to EPA 218.7.

Keywords: chromate, Cr VI