Determination of some herbicide residues in pond water using dispersive liquid-liquidmicro-extraction followed by high performance liquid chromatographyAuthor(s): SNVS.Murthy, Tentu.Nageswara Rao, G.Kumar, N.Krishna Rao, Karri.Apparao, K.Raghu Babu
A rapid and simple extraction and preconcentration method for the determination of herbicide residues (2,4-D Sodium, Ethoxysulfuron and Halosulfuron methyl) in pond water samples using dispersive liquid-liquid micro extraction (DLLME) technique coupled with HPLC-UV was developed. The significant factors in dispersive liquid-liquid microextraction such as volume of extraction, disperser solvent, pH, ionic strength as well as extraction time were investigated and optimized in detail. The optimumexperimental conditions of the proposed method were 5.00 mL aliquot of the sample solution, 5 mL acetonitrile, natural pH containing 5% (w/v) NaCl, while keeping centrifugation time and speed fixed at 10 min, 4000 rpm respectively. The calculated calibration curves gave high-level linearity for all target analytes with correlation coefficients ranging between 0.9997 and 0.9999. The reproducibility and recovery of the proposed method, expressed as relative standard deviation, varied between 85 % to 95 % and 2% to 5%, respectively. The obtained LOQ values were in the range of 0.05 µg/mL.