Differential pulse anodic stripping voltammetric determination of Ni(II) and Co(II) in water and vegetable samples using analytical reagent 2,2’-{benzene-1,2-diylbis (nitrilomethylylidene]} diphenol

摘要

A highly selective, fairly rapid and economical method for the determination of Ni(II) and Co(II) by differential pulse anodic stripping voltammetric method was developed using 2,2'-{benzene-1,2-diylbis (nitrilomethylylidene]}diphenol as a complexing reagent onto hanging mercury drop electrode(HMDE). The optimum experimental conditions were found to be 2,2'-{benzene-1,2-diylbis(nitrilomethylylidene]}diphenol concentration of 3.0mM, NH4OH-NH4Cl buffer (pH-9.0), scan rate of 12mV/sec, accumulation potential of -300.0 mV versus Ag/AgCl, accumulation time of 110sec, and pulse amplitude of 50mV. The peak currents of Ni(II) and Co(II) were directly proportional to the initial metal concentration in the ranges of 0.01-90|ìg/mL under the optimized conditions. A relative standard deviation of 0.52%(n=5) was obtained, and the limit of detection was found to be 0.0042 and 0.0026 |ìg/mlfor Ni(II) and Co(II) respectively. The method was applied to the determination of Ni(II) and Co(II) ions in water and vegetable samples with satisfactory results.