Application of RP-HPLC method for the analysis of some pesticide residues in water samples

Abstract

A reversed-phase high-performance liquid chromatography (RP-HPLC) method for determination of some pesticide residues in different water samples has been developed and validated. The investigated pesticides belong to a different chemical classes, such as: organonitrogen, among which triazines (e.g., atrazinе), organophosphorus (e.g., malathion, fenitrothion, parathion) and phenoxycarboxylic acids (e.g., 2,4-D (2,4-dichlorophenoxy)acetic acid)), which have different chemical structures and polarities. A Purospher STAR RP-8e (30 x 4 mm, 5 µm) analytical column, mobile phase consisted of acetonitrile and water, flow rate of 1 mL/min and constant column temperature at 25 °C were used for successful separation and quantitative determination of target analytes. The UV-detection was performed at 220 nm and 270 nm. Concentration and clean-up of analytes were done by solid-phase extraction (SPE). The developed method was validated according to European Commission guidelines for pesticide residue analytical methods and specificity, selectivity, linearity, precision, accuracy, and limit of quantification (LOQ) were tested for that purpose. The obtained values for relative standard deviation of retention times and peak areas (RSD ≤ 11.26 %), recoveries ranged from 95.01 - 111.20 %, multiple correlation coefficients (R2 ≥ 0.99) revealed that all performance characteristics were found within acceptance criteria. The method was successfully applied for determination of target pesticide residues in different water samples.