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

- Combination of USAE-DLLME-SFO was used for determination of OPPs in summer crops.
- The new method avoided using high density and toxic extraction solvents.
- Extraction time in DLLME stage is short relative to the other methods.
- The method provides good repeatability and high extraction recovery.
- No clean-up or evaporation were required after extraction.

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 μg kg−1 and limit of detections (LODs) are in the range of 1-4 μg kg−1. The relative standard deviations (RSDs) for 100 μg 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.