Square wave stripping voltammetric determination of cyprodinil fungicide in food samples by nanostructured multi walled carbon nanotube paste electrode

Cyprodinil is a fungicide from an anilinopyrimidine group and is widely used in agricultural fields to control fungi that are harmful to vegetables and plants, and therefore requires a reliable, sensitive and selective method for its analysis in food samples. The electrochemical behavior of cyprodinil was investigated by square wave stripping and cyclic voltammetric techniques by using both glassy carbon electrode and multi-walled carbon nano tube paste electrode (MWCNTPE). Prior to analytical determinations, parameters such as pH, frequency, deposition time and deposition potentials were optimized. The oxidation peak potential of cyprodinyl fungicide was + 1160 mV (vs Ag/AgCl). The linear dynamic range was 0.25–4.0 mg/L. The limit of detection and the limit of quantification were calculated as 0.076 and 0.25 mg/L, respectively. In addition, the interference effects of other fungicides in the same class with cyprodinil (pyrimidine fungicides) such as pyrimethanil, nuarimol, fenarimol and another class of dioxacarb (carbamate insecticide) were also investigated. The recommended electroanalytical method was successfully applied to the commercial formulation of Fragman®50 WG containing 50% cyprodinil and apple juice and tap water samples. The percentage of cyprodinil in commercial formulation was calculated as 50.3 ± 3.5% with a relative standard deviation of 6.9% and relative error of 0.65, respectively. The calculated relative standard deviations and high recoveries indicate that the accuracy and precision of the recommended method for is highly acceptable.