Original Articles: 2015 Vol: 7 Issue: 10
Respon surface methodology optimization for the determination of zinc in water sample by adsorptive stripping voltammetry
Abstract
A procedure for the determination of zinc in water sample by adsorptive stripping voltammetry using calcon as a complexing agent has been optimized. The influence of several parameters were studied : variati ons of calcon concentration, pH, accumulation potential and accum ulation time. The design experiment was a central c omposite design with 4 factors/variables, 3 levels and 31 tr eatment combinations. From analysis of variance, it was decided to accept the second-order model and the independen t variable, concluded that a significant effect on the response variable (peak current). Based on data analysis wit h response surface method, the determination of zin c obtained optimum conditions are : calcon concentration 0.62 mM, pH 7.85, accumulation potential -0.61 Volt and accumulation time 48.39 seconds with a maximum peak current 1008.44 nA. At the optimum condition were obtained relative standard deviation 2.5%, recover y 98 %, the linear range 0.2 - 105 μ g/L, coefficient of correlation 0.966 with a detection limit of 1.21 μ g/L. Finally, the method was succesfully applied to the determination of Zn(II) in water samples without pr ior treatment.