Determination of trace arginine by adsorptive voltammetry of its nickel(II) complex

The adsorptive voltammetric wave of the arginine-nickel(II) complex is obse rved In 0.02 M borax buffer solution whose nit is adjusted to 8.5 by nitric acid. The complex is adsorbed strongly on the surface of hanging mercury d rop electrode (HMDE), giving a sensitive reduction peak at -0.82 V (vs SCE) . A linear relationship holds between derivative peak height and the argini ne concentration in the range 1.0 x 10(-8) to 1.0 x 10(-6) mol dm(-3). The detection limit is 5.0 x 10(-9) mol dm(-3). The method has been applied to the detection of arginine in food samples, The mechanism of electrode react ion is dicussed.