Determination of Hexavalent Chromium in Drinking Water According to EPA Method 218.7

This scientific poster looks at modifying EPA Method 218.6 to meet California`s rigorous public health goal (PHG) of detecting 0.02 μg/L of hexavalent chromium in drinking water. Separation is performed using anion-exchange columns from Metrohm; Chromium(VI) is then derivatized with 1,5-diphenylcarbazide in a post-column reaction. This enables a method detection limit (MDL) of 0.01 μg/L. The microbore column guaranteed precise and accurate analytical results within less than six minutes, and the applied flow-through reactor and the UV/VIS detector enabled significant enhancing of the efficiency of the post-column reaction.