Application Note: Chromium in waste water
8 October 2007

Cr(VI) can be determined by polarography at the SMDE (Static Mercury Drop Electrode) in acetate solution containing ethylene diamine to mask interfering copper ions.

Only Cr(VI) is electrochemically active. Therefore all chromium has to be oxidised to Cr(VI) prior to analysis. UV irradiation at pH 4 is used to oxidise chromium.