Preparation of Glassy Carbon Electrode Modified with Polymeric Meso–Tetrakistetrabromo Thienylporphyrin for Determination of Cadmium and Lead by Anodic Stripping Voltammetry

摘要

The use of a glassy carbon electrode modified with polymeric mesoetrakistetrabromothienylporphyrin (TBrTP) to determine Pb(II) and Cd(II) is reported. TBrTP was prepared by electrochemicalpolymerization in acetonitrile. Using SWASV, variables like number of cycles on theelectropolymerization, pH, time and accumulation potential (tacc, Eacc) were optimized. Optimalanalytical conditions were: pH 5.0 (acetate buffer); Eacc .00 V vs. Ag/AgCl and tacc 60 s. The linear calibration curves ranged from 10.0 to 70.0 L for Pb(II) and from 10.0 to 100.0 L for Cd(II). The detection limits (3 were 0.03 and 0.02 L for Pb(II) and Cd(II) respectively. The relative standard deviation was 4.8 % and 6.3 % (n=6), respectively, for a solution containing 10.0 L ofPb(II) and Cd(II). The method was validated using TMDA 51.3 and SPSW1 certified referencematerials and then applied to determination of Pb(II) and Cd(II) in spiked tap water.