IOANA GEORGIANA LAZAR, ELENA DIACU, GEORGE OCTAVIAN BUICA, ELEONORA MIHAELA UNGUREANU,GEORGIANA LUIZA ARNOLD, LIVIU BIRZAN THE HEAVY METALS SENSING BASED ON 2,6-BIS(-2-(THIOPHEN-3-YL)VINYL)- 4-(4,6,8-TRIMETHYLAZULEN-1-YL)PYRYLIUM MODIFIED ELECTRODES This paper focuses on electrochemical characterization of new azulene compound 2,6-bis((E)-2-(thiophen-3-yl)vinyl)-4-(4,6,8-trimethylazulen-1-yl)pyrylium (L) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), rotating disk electrode voltammetry (RDE) on glassy carbon disk working electrodes. The character of redox processes was established by CV and RDE using increasing scan rates at different scan domains. PolyL modified electrodes have been prepared by scanning or controlled potential electrolysis (CPE). The complexing properties of L and polyL have been investigated towards detection of heavy metal ions by anodic stripping technique. The voltammetric curves present well defined peaks for Pb2+, Cd2+, Cu2+ and Hg2+, which can be used as analytical signals for their determination. The performances of the modified electrodes obtained at different potentials and charges have been evaluated. The best results have been obtained for Pb2+ and Cd2+ with the achievement of detection limits of 10-7 M.
Keywords: 2,6-bis((E)-2-(thiophen-3-yl)vinyl)-4-(4,6,8-trimethylazulen-1-yl)pyrylium, voltammetric methods, modified electrodes, anodic stripping, heavy metal ions