Green electrochemical sensor for environmental monitoring of pesticides: Determination of atrazine in river waters using a boron-doped diamond electrode

A novel, simple and sensitive electrochemical method for the determination of atrazine using a square-wave voltammetry on boron-doped diamond electrode was developed. Atrazine provided a single well-defined reduction peak at −1.1 V vs. Ag/AgCl electrode in Britton–Robinson buffer solution at pH 3. The effect of supporting electrolyte, pH and scan rate on the current response of atrazine was studied to select the optimum experimental conditions. The linear concentration range from 0.05 to 40 μM (R2 = 0.999, n = 6), the good repeatability (relative standard deviation of 2.9% at 10 μM for n = 6) and the detection limit of 10 nM were achieved at optimized square-wave voltammetric parameters (step potential of 5 mV, frequency of 60 Hz and amplitude of 80 mV). The influence of possible interfering agents appeared to be minor which evidently proved the good selectivity of method. The proposed method was successfully applied for the determination of atrazine in spiked river water samples with satisfactory recoveries (92 to 100%) and the good agreement to results obtained by reference high performance liquid chromatography method at confidence interval for 95% probability. In this way, boron-doped diamond could represent an environmentally acceptable (green) alternative to highly toxic mercury electrodes for monitoring of pesticides.