Dispersive liquid-liquid microextraction combined with non-aqueous capillary electrophoresis for the determination of imazalil, prochloraz and thiabendazole in apples, cherry tomatoes and grape juice

BACKGROUNDFruit and vegetables are frequently treated with fungicides to reduce possible spoilage. As a result, fungicide residues may be accumulated in derived products. This important group of chemical compounds has been heavily regulated because of their potential toxicity. Therefore, a simple and rapid method to determine fungicides is desired. RESULTSA simple non-aqueous capillary electrophoresis (NACE) method based on dispersive liquid-liquid microextraction (DLLME) has been proposed for the determination of imazalil, prochloraz and thiabendazole fungicides in fruits and juice samples. Separation buffer consisted of a methanol-acetonitrile mixture (35:65, v/v) containing 30mmolL(-1) ammonium chloride and 0.5% phosphoric acid. The optimum DLLME conditions were 80 mu L trichloromethane as extraction solvent, 0.5mL tetrahydrofuran as disperser solvent, sample solution pH at 6.0, 5% (w/v) NaCl and 10s extraction time. Recoveries obtained for various samples ranged from 72% to 102%, with relative standard deviation lower than 6.4%. The limits of detection ranged from 0.47 to 0.72 mu gkg(-1). CONCLUSIONThe proposed method takes the advantages of DLLME and NACE. It is rapid, accurate, sensitive and reproducible for the determination of imazalil, prochloraz and thiabendazole in fruit samples. (c) 2014 Society of Chemical Industry