Electrochemical behavior study of some selected phenylurea herbicides at activated pencil graphite electrode. Electrooxidation of linuron and monolinuron

A novel and rapid voltammetric assay for the simultaneous determination of monolinuron (MLN) and linuron (LIN) using an electrochemically pretreated pencil graphite electrode (PGE*) is reported for the first time. Enhanced oxidation peak currents of MLN and LIN were observed at PGE* when compared with electrochemically non-pretreated PGE. Differential pulse voltammetric (DPV) results showed distinct anodic peaks at 1.064 V and 1.170 V for MLN and LIN, respectively. Under optimum conditions, the detection limits were 3.7 x 10(-7) mol L-1 and 5.8 x 10(-7) mol L-1 for MLN and LIN respectively. The DPV method was applied for the quantitative determination of the mentioned compounds in spiked tap water samples enriched by solid phase extraction. The voltammetric results were in good agreement with high-performance liquid chromatography data.