Determination of copper in food by stripping voltammetry using Cu(II)–[2-(2,3,5-triazolylazo)-5-dimethylaninobenzonic] complex

Abstract

The electrochemical behavior of copper (II)-2-[2,3,5-triazolylazo]-5-dimethyl-aninobenzonic [Cu(II)–TZAMB] complex was studied. In 0.05 mol l −1 potassium hydrogenphthalate (PBS, pH 2.5) buffer solution, Cu(II) and TZAMB can form Cu(II)–TZAMB complex. This complex has adsorptive characteristics on hanging mercury drop electrode (HMDE) and can be reduced in an irreversible reduction step. The calibration graph for copper(II) was linear over the concentration range 9.5×10 −9mol l −1 to 4.7×10 −7 mol l −1; the detection limit of the method was 9.5×10 −9 mol l −1. The interference of some common ions was studied and the method was found suitable for the determination of copper(II) in rice and vegetables.