Voltammetric Monitoring of Photodegradation of Clothianidin, Nitenpyram and Imidacloprid Insecticides Using a Tricresyl Phosphate-Based Carbon Paste Electrode

摘要

A voltammetric investigation of two commercial neonicotinoid insecticides, Clothianidin (Clo) andNitenpyram (Nit), was carried out and completed with the third one, Imidacloprid (Imc), from aprevious study when using two different types of carbon paste electrodes made from graphite powderand silicone oil (SO-CPE) or tricresyl phosphate as the binder (TCP-CPE). For all substances ofinterest, the latter has been found superior with respect to the signal-to-noise characteristics and theoveral electroanalytical performance. Subsequently, a new method employing the direct differentialpulse voltammetry (DPV) and the TCP-CPE has been proposed for the determination of Clo and Nit at-1 the low g mL concentration level; all the key parameters being applicable also to Imc. Finally, theprocedure combining DPV with the TCP-CPE could be applied for the monitoring of the photolyticand TiO2-assisted photocatalytic degradation of Clo, Nit, and Imc via their voltammetrically detectabledisappearance, when the quantitative and kinetic data obtained have agreed well with the results of thereference HPLC/DAD measurements.