Determination of components of the Cd(II)-Pb(II)-Cu(II) system in aqueous solutions of (polyethylene imine)methylthiourea by stripping voltammetry

Conditions were studied for the stripping voltammetric determination of com ponents of the Cd(II)-Pb(II)-Cu(II) system in aqueous solutions of (polyeth ylene imine)methylthiourea (PMT), the most efficient polymer complexant for the membrane preconcentration of heavy metal ions. It was shown that PMT s ignificantly enhances the selectivity of determining Pb(II) and Cd(II) in s olutions of Cu(II) by stripping voltammetry. Pb(II) and Cd(II)can be determ ined in the presence of up to 200- and 50-fold amounts of Cu(II), respectiv ely. The limits of detection for Pb(II) and Cd(II) after a 40-s accumulatio n were 6.9 x 10(-8) and 6.8 x 10(-7) M, respectively.