Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560210 | Talanta | 2005 | 5 Pages |
Abstract
A sensitive adsorptive stripping voltammetric protocol at a bismuth-coated glassy-carbon electrode for trace measurements of chromium (VI) in the presence of diethylenetriammine pentaacetic acid (DTPA) is described. The new protocol is based on accumulation of the Cr-DTPA complex at a preplated bismuth film electrode held at â0.80Â V, followed by a negatively-going square-wave voltammetric waveform. Factors influencing the stripping performance including the film preparation, solution pH, DTPA and nitrate concentrations, deposition potential and deposition time, have been optimized. The resulting performance compares well with that observed for analogous measurements at mercury film electrodes. A preconcentration time of 7Â min results in a detection limit of 0.3Â nM Cr(VI) and after 2Â min a relative standard deviation at 20Â nM of 5.1% (n = 25). Applicability to river water samples is demonstrated. The attractive behavior of the new “mercury-free” chromium sensor holds great promise for on-site environmental and industrial monitoring of chromium (VI). Preliminary data in this direction using bismuth-coated screen-printed electrodes are encouraging.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Lin Lin, Nathan S. Lawrence, Sompong Thongngamdee, Joseph Wang, Yuehe Lin,