رضا اوجانی

Heavy metal ions are the hazardous pollutants in the environment around us [1]. Some electrochemical methods have been applied to determine these metal ions [2]. In this study, an antimony trioxide modified multi-walled carbon nanotube paste electrode (Sb2O3/CNTPE) was employed for square wave anodic stripping voltammetric (SWASV) measurement of Cd2+ and Pb2+ ions. For estimating the morphology and properties of the modified electrode, the field emission-scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS) methods were applied. SWASV measurements were done in 0.01 M HCl at -1.2 V vs. Ag|AgCl|KCl (3 M) for 130 s as deposition step. After equilibrium time of 15 s, an SWASV signals appeared at -0.7 for Cd2+ and -0.5 V for Pb2+ vs. Ag|AgCl|KCl (3 M) as stripping step. The Sb2O3/CNTPE revealed a good linear operation in the examined concentration range of 10-100 ppb Cd2+ and Pb2+ with appropriate detection limits of about 1.7 ppb for Cd2+ and 1.2 ppb for pb2+, respectively. The stability of the modified electrode during 7 weeks and its behavior in the presence of some other metal ions were evaluated. Finally, the method was successfully tested via measuring Cd2+ and Pb2+ in tap water. References [1] Araya M.; Olivares, M.; Pizarro, F.; Gonzlez, M.; Speisky, H.; Uauy, R.; Am. J. Clin. Nutr., 2003, 77, 646 [2] Lund, W. The Importance of Chemical “Speciation” in Environmental Processes. Springer Berlin Heidelberg, 1986, 533