Determination of molybdenum by adsorptive anodic stripping voltammetry of molybdenum-alizarin violet complex at an acetylene black paste electrode

A reliable and sensitive procedure for the determination of trace levels of molybdenum by adsorptive anodic stripping voltammetry is proposed. The method is based on adsorptive accumulation of the molybdenum (Mo)-alizarin violet (AV) complex onto an acetylene black paste electrode (ABPE), followed by oxidation of the adsorbed species by voltammetric scan using a second-order derivative modulation. For voltammetric determination of molybdenum, the parameters influencing the peak current have been optimized. Under the selected conditions, the electrode demonstrated linear response over a wide range of Mo(VI) concentration (6.0 x 10(-9)-1.0 x 10(-5) mol/L), the detection limit was 2.0 x 10(-9) mol/L (S/N = 3) for 120 s accumulation. The effects of potential interfering ions were studied, and it was found that the proposed procedure was free from most interferences. The method has been applied to the determination of molybdenum in plant foodstuffs, and satisfied results were obtained. (C) 2010 Elsevier Ltd. All rights reserved.