ADSORPTIVE STRIPPING VOLTAMMETRIC METHODFOR THE INDIVIDUAL DETERMINATION OFCd(II), Cu(II), Pb(II), AND Zn(II) IN VEGETABLESAMPLES USING CALCEIN

Adsorptive stripping voltametric method is presented for the individual determination of Cd(II), Cu(II), Pb(II) and Zn(II) in vegetable samples using calcein as a complexing agent. The purpose of this study was to obtain the optimum condition of each metal ions. The optimized experimental conditions include: concentration of 0.2 mM calcein for Cu(II) and Cd(II), 0.6 mM for Zn(II), and 0.7 mM for Pb(II); pH 6 for Cd(II) and Zn(II), pH 7 for Cu(II) and Pb(II); accumulation potential -0.4 V for Cd(II) and Pb(II), -0.6 V for Zn(II) and Cd(II); accumulation time 70 s for Cd(II), 50 s for Cu(II) and 60 s for Pb(II) and Zn(II). This method has been applied to determine relative standard deviation (RSD) were (0.39; 0.74; 1.35 and 0.41)% for Cd(II), Cu(II), Pb(II) and Zn(II) with eight replicates (n = 8) measurements of 10 g/L Cd(II), Cu(II), Pb(II) and Zn(II); with recovery are: (99.11; 99.88; 98.76 and 99.79)%. Linear range for Cd(II) and Pb(II) (0.2 -110) g/L, while Cu(II) and Zn(II) (0.2 -100) g/L . Limit of detection (LOD) (1.3871; 0.7663; 1.4372 and 0.9831) g/L.