Simultaneous Determination of Dimethomorph and Chlorothalonil in Pesticide Formulation: HPLC Method Development and Validation

Abstract

The identification and accurate quantification of pesticides is important to verify the recommendedconcentration of active content of each pesticide in formulated products to avoid adverse effects on human life due toover dosage. In this study, method of quantitative determination of Dimethomorph and Chlorothalonil in pesticideformulation was developed and validated by using ICH guidelines. Chromatographic separations with good resolutionwere performed on Beckman C-18 column (5 µm x 150 mm x 4.6 mm), using 80:20, v/v – (CH3CN:H2O) as mobilephase in isocratic mode at 230 nm. The retention time for Dimethomorph and Chlorothalonil at flow rate 1.2 mL/minwas 6.21 and 9.63 minutes, respectively. Calibration curves of both studied fungicides (Chlorothalonil andDimethomorph) were linear showing coefficient of determination greater than 0.996. %RSD value of inter-dayprecision was found to be less than 3 for both pesticides and for intra-day precision these values were less than 2. Interlaboratory comparison (ILC) method was applied to evaluate the accuracy of the proposed method and Z-score valueswere found to be less than 2. The proposed method is therefore efficient, accurate, and cost-effective and can suitablybe used for simultaneous quantitative determination of Dimethomorph and Chlorothalonil in pesticide formulatedproducts.