Aqueous acetonitrile extraction for pesticide residue analysis in agricultural products with HPLC−DAD

To reduce hazardous organic solvent consumption during sample preparation procedures as much as possible, an extraction method of smallest feasible sample volume (5 g) using aqueous acetonitrile (MeCN) was developed to extract pesticide residues from agricultural samples prior to HPLC−DAD determination. Extraction with MeCN/water (1:1, v/v), and adjustment of the MeCN concentration by diluting with water after extraction recovered successfully most pesticides showing various physicochemical properties. The matrix effects of tested samples on the proposed method developed herein were generally negligibly-small. The average recoveries were in the range 70-120% for all pesticides with the coefficient of variation values below 20%. The reduction rate of organic solvents used for the proposed sample preparation method was up to approximately 60% compared with the Japanese authorised official method for pesticide residue analyses. These results demonstrate the feasibility of the proposed method for pesticides with diverse properties.