Investigations of electrochemical behavior of triazine group pesticides and their determinations

In this work, new electroanalytical methods were developed for the determination of triazine pesticides ?cyromazine, anilazine and cyanazine? using voltammetric techniques.For the determination of cyromazine, a sensitive analytical method was developed using glassy carbon (GC) and carbon nano tube paste electrode (CNTPE) by square wave stripping voltammetry (SWSV). The calibration curve obtained from SWSV using CPE was linear in the range of 0.41 to 83.30 ? g /mL with a detection limit of 0.12 µg/mL. The method was extended to determination of cyromazine in agrochemical formulation Trigard ? with recovery of 100.49 % and accuracy was in agreement with that obtained by comparison HPLC method.Voltammetric oxidation behavior of anilazine was investigated by SWSV and cyclic voltammetry (CV) using GCE. The pesticide anilazine was found to give a single oxidation peak over the pH range of 1.0-9.0 and the pH dependency of the peak potential showed a linear segment. The relationship between the peak current and anilazine concentration was linear in the range of 0.11- 3.50 ? g/mL with a detection limit of 0.03 ? g/mL. Reduction behavior of anilazine was investigated by differential puls polarography and linear calibration range was found as 1.16 ? 17.50 ?g/mL. The interferences with the reduction peak of anilazine peak observed with several commonly used pesticides and inorganic species were also tested. Some interfering species were eliminated either by providing selectivity with pH changes or using complexing agents, e. g., EDTA.Voltammetric behavior of cyanazine was investigated by SWSV and CV at hanging mercury drop electrode. The relationship between the peak current and cyanzine concentration was linear in the range of 1.56- 100.5 ? g/L with a detection limit of 0.47 ? g/L The applicability and validation of the proposed SWS voltammetric method for the assay of cyanazine in spiked natural water and soil were investigated. The recoveries calculated for river water and soil samples spiked with 10.0 ? g/L cyanazine were 97 and 91 % with relative standard deviations of 1 and 2%, respectively.The good recoveries and low relative standard deviations for the data reflect the high accuracy and precision of the proposed electrochemical methods for determination of triazine pesticides.