A simple, rapid, reliable and fully validated differential pulse adsorptive cathodic stripping voltammetric procedure has been developed for determination of the curcumin in human serum and turmeric, based on its electrochemical reduction at a hanging mercury drop electrode. The Britton–Robinson (BR) buffer of pH 9.5 was found to be reasonable as a supporting electrolyte for the assay of the compound. The effect of different parameters, such as pH, accumulation potential and accumulation time, on the sensitivity of method was evaluated. Under the optimized conditions (accumulation potential –0.3 V, accumulation time 50 s, BR buffer pH 9.5), curcumin was generated one irreversible cathodic peak. This cathodic peak showed a linear dependence on the concentration of curcumin over the range of 5.0 × 10–9–2.8 × 10–7 mol l–1. The obtained detection limit under the optimal experimental conditions is 1.5 × 10–9 mol l–1 after 50 s of the accumulation time. The relative standard deviation of 1.12% for concentration of 5.0 × 10–8 mol l–1 with 50 s accumulation time was obtained. The procedure was used successfully to the assay of the curcumin in turmeric and spiked human serum, and a good agreement was obtained between the results of the proposed method and high performance liquid chromatography (HPLC) analysis.

Faculty of Chemistry Razi University Kermanshah Iran

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