Simple, selective and sensitive voltammetric method for the determination of herbicide (paraquat) using a bare boron-doped diamond electrode

A simple, selective and sensitive electroanalytical method for detection of paraquat on a bare boron-doped diamond electrode (BDDE) using square-wave voltammetry is demonstrated. It was found that paraquat provided a highly reproducible and well-defined reduction peak in aqueous media (ammonia buffer, pH 9.0) using BDDE. Excellent linear response of peak current on the paraquat concentration in the range from 5 x 10(-9) to 1 X 10(-6) MOl L-1, good repeatability (RSD 3.2%) and low detection limit of 1.5 X 10(-9) MOl L-1 without any chemical modifications and electrochemical pretreatment of the electrode surface were evaluated. The effect of possible interferences appeared to be negligible which proved very good selectivity. The proposed method was successfully applied to paraquat determination in natural water samples collected from a Polish river and sea. (C) 2014 Elsevier B.V. All rights reserved.