title: Combination of hollow-fiber-supported liquid membrane and dispersive liquid-liquid microextraction as a fast and sensitive technique for the extraction of pesticides from grape juice followed by high-performance liquid chromatography.
abstract: The simultaneous use of a hollow-fiber-supported liquid membrane and dispersive liquid-liquid microextraction for the determination of pesticides directly in grape juice was investigated. The detection and quantification were performed by liquid chromatography with diode array detection. The optimum extraction condition was reached by filling the pores of the membrane wall with dodecanol and using hexane/acetone as extraction/dispersion solvents. Salt addition had a highly negative effect on the extraction efficiency and the optimum extraction time was 60 min. The volume of hexane/acetone mixture and the sample pH did not affect the signal at the levels studied. Therefore, an intermediate amount of these solvents (250 μL; 1:7.5 v/v) and pH 6 were selected. The optimum desorption condition was obtained with acetonitrile and 10 min of desorption time. The linear working range varied from 58 to 500 μg/L (parathion-methyl), 62-500 μg/L (difenoconazole) and 107-500 μg/L (chlorpyrifos), with correlation coefficients ranging from 0.9980-0.9942. The limits of detection and quantification found were, respectively, 17 and 58 μg/L for parathion-methyl, 19 and 62 μg/L for difenoconazole and 32 and 107 μg/L for chlorpyrifos. The relative standard deviation ranged between 3.5 and 11.2%.
authors: Departamento de Química da Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors: Vanessa Dutra
authors: VD
authors: Silva
authors: Departamento de Química da Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors: Vanessa
authors: V
authors: Simão
authors: Departamento de Química da Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors: Adriana Neves
authors: AN
authors: Dias
authors: Departamento de Química da Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors: Jeferson Schneider
authors: JS
authors: Carletto
authors: Departamento de Química da Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors: Eduardo
authors: E
authors: Carasek
mesh_terms: D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D010575:Pesticides / Q000302:isolation & purification*; D012015:Reference Standards; D027843:Vitis
chemical_list: D010575:Pesticides
keywords: Dispersive microextraction; Grape juice; Hollow fibers; Pesticides