Abstract: An electrochemical method was developed for the sensitive and selective determination of melamine in milk samples. The sample preparation involved extraction with acetocaustin and clean-up on a solid phase extraction column. The cyclic voltammetry was used to determine melamine in 1.0 mol/L H2SO4 solution, and a strong and stable current of reduction and oxidation peak was observed in the presence of melamine. Under optimal experimental conditions, the glassy carbon electrode (GCE) offered a highly sensitive and rapid response to melamine at the potential of 0.7 V for Ag/AgCl/saturation KCl in 1.0 mol/L H2SO4. The developed method displayed a good linearity over the range of 15－345 mg/kg with a detection limit of 5 mg/kg. The relative standard deviation (RSD) and recovery rate of this method were 3.5%－4.5% and 97.3%－101.2%, respectively. Compared with other reported methods, this method had multiple advantages, such as a broader linear range, a lower detection limit, easier sample pretreatment, quicker determination, lower cost and no requirements for complicated equipments.

Key words: melamine, cyclic voltammetry, milk, glassy carbon electrode (GCE)