ANYL 133 |
| A fast, sensitive and selective method for the determination of cadmium based on the reaction of the metal with guanine (G) to form a Cd(G)2 complex which is adsorbed on the mercury electrode is presented. The reduction current of the accumulated complex is measured by scanning the potential in the cathodic direction. The variation of peak current with pH, adsorption time, adsorption potential, ligand concentration, and some instrumental parameters such as stirring rate in the accumulation stage, and step amplitude, pulse amplitude and step duration while obtaining the square wave voltamperograms were optimized. The best experimental parameters were choosing using univariable and multivariable experimental design. The values obtained by both methods were similar: CG = 150 ?mol L-1, tads = 30 s, and Eads = -0.30 V vs Ag/AgCl (KCl 3M). A linear response is observed over the 0.0–24.0 ?g L-1 concentration range, with a detection limit of 0.9 µg L-1. Reproducibility for 12.0 µg L-1 cadmium solution was 1.9% (n = 7). Synthetic sea water, fortified water (GBW08607) and sediment (GBW08301) reference material were used for validation measurements. |
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General Posters
7:00 PM-9:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Analytical Chemistry |