Differential pulse voltammetric indirect determination of aluminium in drinking waters, blood, urine, hair, and medicament samples using l-dopa under alkaline conditions

Abstract

The differential pulse voltammetric (DPV) indirect determination of aluminium using L-dopa under alkaline conditions on a glassy carbon working electrode was studied. The proposed method relies on the linear decrease of the DPV anodic peak current of L-dopa with increase in the concentration of aluminium added. Under the optimum experimental conditions (pH 8.5, 0.08 M NH₄Cl–NH₃·H₂O buffer solution, and 4 × 10⁻⁴ M L-dopa), the linear range is 2–18 × 10⁻⁷ M Al ^III. The detection limit is 7.6 × 10⁻⁸ M and the relative standard deviation for 8 × 10⁻⁷ M Al ^III is 3.5% (n = 8). A number of foreign species were examined as potential interferents. The method was applied to the determination of aluminium in drinking waters, synthetic renal dialysate, sodium chloride injection, sucrafate, hydrothorax, blood, urine and hair samples. The physiological significance is discussed.