An oxidative procedure for the electrochemical determination of chromium(VI) using modified carbon paste electrodes

A new electrochemical methodology to determine Cr(VI) in aqueous solutions is presented, The key to this methodology is in the oxidation range. This procedure is based on the electrochemical response of Cr(VI)/1,5-diphenylcarbazide (DPCI) complex as analyzed by differential pulse voltammetry and cyclic voltammetry. This new sensitive, fast and economic alternative for the determination of Cr(VI) offers a number of advantages: good detection limit; decrease in the duration of analysis (since it is not necessary to work with a deoxygenated atmosphere and removal of all interferents, followed in reduction procedures). The use of the reagent DPCI directly in the material of the electrode is also broached. Finally, the proposed methodology was applied to the determination of Cr(VI) in real seawater samples.