Research Article

Detection of Organophosphorus Pesticides in Wheat by Ionic Liquid-Based Dispersive Liquid-Liquid Microextraction Combined with HPLC

Figure 6

Effects of ultrasonic time on EFs (a) and ERs (b). Extraction conditions: solvent, methanol; solvent volume, 1 mL; extractant, [OMIM][Tf2N]; extractant volume, 22 L; extraction temperature, room temperature; ultrasonic time, 2 min, 5 min, 8 min, 11 min, and 14 min, respectively; centrifugal time, 5 min.
(a)
(b)