Determination of trace amounts of mercury by pure carbon-paste and by chemically modified carbon-paste electrodes

Abstract

A differential pulse anodic stripping voltammetric method was developed for the determination of trace amounts of mercury in water samples using pure carbon-paste electrode. The method offered a sensitivity of 410 nA/ppm. In order to improve selectivity several' chemically modified C-paste electrodes were prepared and investigated. By this study it was found that at pH 10.5, in 0.1 M sodium acetate solution, the hydroxylamine modified carbon-paste electrode accumulated mercury non-electrochemically at ppm levels. Using this electrode, an adsorptive stripping voltammetric method, offering a sensitivity of 105 nA/ppm, was developed for mercury determination.