Indirect Differential Pulse Voltammetric Determination of Aluminum Biological Samples in the Presence of 3, 4-Dihydroxyphenylalanine

ABSTRACT

Indirect differential pulse voltammetric (DPV) determination of aluminum in the presence of 3, 4-dihydroxyphenylalanine (L-dopa) with glass carbon electrode as working electrode has been described. The method relies on the decrease of DPV anodic peak current of L-dopa with the addition of Al^III The decreasing value of the peak current is linear with the increase of Al^III concentration. Under the optimum experimental conditions (pH 4.8, 6×10^?4 M L-dopa, 0.06M NaAc - HAc ¹buffer solution), the linear ranges are 4.0×10^?7 - 5.2×10^?6 M and 7.2×10^?6 - 4.5×10^?5 M. The relative standard deviation for 8×10^?6 M aluminum is 1.0% (n = 8) and the detection limit is 3.5×10^?7 M. A number of foreign species for interference have been studied. The method has been applied to determine aluminum in drinking water, synthetic renal dialysate and urine samples.