A sensitive voltammetric method for the determination of parathion insecticide Original Research Article

A sensitive voltammetric method is developed for the determination of parathion (φNO2) using a Nafion®-coated glassy carbon electrode. In this method, parathion is first irreversibly reduced from φNO2 to φNHOH. The reversible peaks at around +0.33 V (versus Ag/AgCl) corresponding to a two-electron oxidation/reduction of hydroxylamine (φNHOH) to the nitroso (φNO) derivative were used for detection with square-wave voltammetry. The experimental parameters, such as, pH, film thickness, preconcentration potential, preconcentration time, and square-wave voltammetric parameters were optimized. Using this method, a linear calibration curve for parathion was obtained up to 15 μM range in pH 1.1 citrate buffer solution with a detection limit (S/N = 3) of 50 nM.