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.

Keywords::

• aluminum; 3, 4-dihydroxyphenylalanine
• differential pulse voltammetry
• glass carbon electrode