Wang Joseph, Lu Donglai, Thongngamdee Sompong, Lin Yuehe, Sadik Omowunmi A
Departments of Chemical & Materials Engineering and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
Talanta. 2006 Jun 15;69(4):914-7. doi: 10.1016/j.talanta.2005.11.029. Epub 2005 Dec 20.
Bismuth-coated glassy carbon electrodes have been successfully applied for catalytic adsorptive stripping voltammetric measurements of low levels of vanadium(V) in the presence of chloranilic acid (CAA) and bromate ion. The new protocol is based on the accumulation of the vanadium-chloranilic acid complex from an acetate buffer (pH 5.5) solution at a preplated bismuth film electrode held at -0.35V (versus Ag/AgCl), followed by a square-wave voltammetric scan. Factors influencing the adsorptive stripping performance, including the CAA and bromate concentrations, solution pH, and accumulation potential or time have been optimized. The response compares favorably with that observed at mercury film electrodes. A linear response is observed over the 5-25mug/L concentration range (2min accumulation), along with a detection limit of 0.20mug/L vanadium (10min accumulation). High stability is indicated from the reproducible response of a 50mug/L vanadium solution (n=25; R.S.D.=3.1%). Applicability to a groundwater sample is illustrated.
铋膜玻碳电极已成功应用于在氯冉酸（CAA）和溴酸根离子存在下对低含量钒（V）的催化吸附溶出伏安测量。新方法基于在预镀铋膜电极上，于-0.35V（相对于Ag/AgCl）下从乙酸盐缓冲液（pH 5.5）溶液中富集钒 - 氯冉酸络合物，随后进行方波伏安扫描。对影响吸附溶出性能的因素，包括CAA和溴酸盐浓度、溶液pH值以及富集电位或时间进行了优化。该响应与在汞膜电极上观察到的响应相比具有优势。在5 - 25μg/L浓度范围内（2分钟富集）观察到线性响应，同时钒的检测限为0.20μg/L（10分钟富集）。50μg/L钒溶液的可重复响应表明其具有高稳定性（n = 25；相对标准偏差 = 3.1%）。展示了该方法对地下水样品的适用性。
