Voltammetric behaviour and square-wave voltammetric determination of the potent antioxidant and anticarcinogenic agent ellagic acid in foodstuffs.

The voltammetric behaviour of ellagic acid (EA) is investigated by cyclic, differential pulse and square-wave voltammetry (CV, DPV and SWV, respectively). Based on the anodic oxidation peak at approximately 0.42V in acetic/acetate buffer (pH 5.5) a robust and a highly reliable square-wave voltammetric method is presented for the determination of EA. The oxidation peak current was linearly dependent on the concentration of EA in the range of 1.0×10(-7)-1.5×10(-6)mol/L (r=0.9997), with a detection limit of 1.0×10(-8)mol/L (S/N=3) and a quantification limit of 3.4×10(-8)mol/L (S/N=10), good reproducibility and a satisfactory level of selectivity towards others polyphenols. The proposed method was applied to the determination of free and total EA in fruits, nuts and juices with good analytical results being obtained.