"APPLICATION OF CENTRAL COMPOSITE DESIGN OPTIMIZATION TECHNIQUE FOR DETERMINATION OF COPPER IN FRUIT AND VEGETABLE SAMPLES WITH ADSORPTIVE STRIPPING VOLTAMMETRY IN THE PRESENCE OF CALCEIN "

This study was to optimize the determination of copper by adsorptive stripping voltammetry (AdSV) in the presence calcein. The independent factors that affect the response were: calcein concentration, pH, potential accumulation and time accumulation. The research design was used a central composite design (CCD) with 4 variables, 5 levels and 31 a combination of treatments. The first step of 2 k factorial design optimization is: to give the highest level of code values (+1.68), the lowest level (-1.68) and code (0) as the center point. Programs were used for statistical data processing, Minitab 17. The obtained optimum conditions for the determination of copper were: calcein concentration 0.11 mM, pH 6.8, potential accumulation -0.88 V and time accumulation 42.34 s. The RSD 0.74%, recovery 99.88%, the linear calibration graph for the concentration (0.2 -110.0) g/L, and the detection limits 1.79 g/L. This procedure was applied for the determination of copper in the fruit and vegetable samples with satisfactory results.