Standardization and Validation of Method for Estimation of Four Insecticide Residues in Soil and Water Matrices by Liquid Chromatographic Technique

A simple, fast and selective method for residue analysis of four insecticides (carbendazim, carbofuran, imidacloprid and carbaryl) by HPLC-UV-PDA is reported. It employs methanol: water (60: 40, v/v) at flow rate of 0.6 mL min⁻¹ as mobile phase in single chromatographic run of 30 min. Performance of the method was validated by analysis of soil and fortified water samples at 5.0, 2.0 and 1.0 μg g⁻¹ by two different analysts. The validation included calibration curve, linearity, limits of detection and quantification, accuracy and precision. The recovery was studied using different organic solvents, dichloromethane, chloroform, hexane and ethyl acetate in four replicates each with fortified water and soil samples at 5.0 μg mL⁻¹. The average recoveries were ranged between 77 to 92 percent with acceptable precision (RSD of 3.3 to 9.4%). The limits of detection and quantification for all the pesticides were 0.009–0.026 in case of water and 0.01–0.031 in soil samples whereas 0.029–0.091 in water and 0.039–0.146 μg g⁻¹ in soil matrix respectively.