Rotating sorptive extraction (RSE) as a green approach for determining pesticides from fruit and vegetable wash-water using GC–MS

In this work, a simplified device based on rotating disk sorptive extraction is described for the first time and denominated rotating sorptive extraction (RSE). Cork disks fitted with magnetic bars were applied for the extraction of 5 pesticides (carbofuran, molinate, trifluralin, atrazine and tebuconazole) in fruit and vegetable wash-water samples obtained from lettuce, apple, banana, orange, and mango washes. The proposed method was optimized using multivariate procedures. Ethyl acetate was used as desorption solvent, as indicated by a simplex-lattice design. Time and volume of desorption were 30 min and 1 mL, respectively. The optimum extraction conditions were 35 min of extraction using 30% of salt. Under these conditions, the LOD obtained for the analytes was 0.95 µg L−1, except for carbofuran, which was 1.89 µg L−1; coefficients of determination ranged from 0.990 to 0.998. Relative recoveries in these samples varied from 84.4% to 135.8%, and relative standard deviation from 1.0 to 23.6%. The device is simple, easily obtainable and made of discarded biomaterial. The method was applied for the extraction of real samples and tebuconazole was found in lettuce and apple wash-water, at a concentration of 27.26 and 2.42 μg L−1, respectively.