Trace measurement of dithiocarbamate based pesticide by adsorptive stripping voltammetry Original Research Article

This paper reports a sensitive and rapid scheme of adsorptive stripping voltammertry to measure a dithiocarbamate based pesticide, Zineb. Zineb can be preconcentrated onto the mercury electrode surface and is subsequently determined by a cathodic scan. Zineb is preconcentrated at −0.3 V (vs. Ag/AgCl) onto a mercury drop electrode with a surface area of 0.0133 cm2/drop. Subsequently, the preconcentrated Zineb species is measured by scanning the potential negatively from −0.3 to −0.7 V. Thus, the necessary sensitivity can be enhanced more than 15 times with a preconcentration time of 120 s to meet the requirement of acceptable daily intakes (ADIs). The calibration plot is linear to 1 μM and the sensitivity is 759.85 nA/μM with a correlation coefficient of 0.999. The detection limit of S/N=3 is 1 nM. A relative standard deviation of 3.8% is obtained from a series of 15 repetitive measurements of 0.4 μM Zineb.