CATHODIC STRIPPING VOLTAMMETRY OF PARAQUAT ON A CARBON PASTE ELECTRODE ELECTRODE MODIFIED WITH AMBERLITE XAD-2 RESIN

A carbon paste electrode chemically modified with Amberlite XAD-2 resin was used for the determination of paraquat by cathodic stripping voltammetry. A previous study on the electrochemical behavior of paraquat showed that the cathodic peak at -0.70 V (vs. Ag/AgCl) permits adequate quantification of the analyte. The response was characterized in terms of preconcentration period, bulk concentration, pH, paste composition, supporting electrolyte and other parameters. The procedure exhibits good linearity for concentrations of paraquat lower than 1.08-mu-g ml-1 with a detection limit of 0.10-mu-g ml-1. The proposed method is suitable for the determination of paraquat in river water.