Determination of organophosphorous pesticides in summer crops using ultrasound-assisted solvent extraction followed by dispersive liquid-liquid microextraction based on the solidification of floating organic drop

The ultrasound-assisted solvent extraction (UASE) followed by dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) has been developed for extraction and determination of organophosphorous pesticides from summer crops. Organophosphorous pesticides were determined by high performance liquid-liquid chromatography-ultraviolet detector (HPLC-UV). Some effective parameters on extraction were studied and optimized. Under the optimum conditions, recoveries for different fruits are in the range of 44.0-61.0%. The calibration graphs are linear in the range of 5-800 mu g kg(-1) and limit of detections (LODs) are in the range of 1-4 mu g kg(-1). The relative standard deviations (RSDs) for 100 mu g kg(-1) of OPPs in different fruits are in the range of 5.5-9.1 (n = 5). The obtained results show that UASE-DLLME-SFO combined with HPLC-UV is a fast and simple method for the determination of pesticides in summer crops. (C) 2013 Elsevier Ltd. All rights reserved.