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

Department of Chemistry, Shandong University, Jinan, 250100, P. R. China

Manuscript received 19 March 1998, accepted 18 July 1998

The adsorptive voltammetric wave of the arginine-nickel(II) complex is observed in 0.02 M borax buffer solution whose pH is adjusted to 8.5 by nitric acid. The complex is adsorbed strongly on the surface of hanging mercury drop electrode (HMDE), giving a sensitive reduction peak at -0.82 V (vs SCE). A linear relationship holds between derivative peak height and the arginine 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 reaction is discussed.