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

Figure 7

Effect of aqueous solution temperature on EFs (a) and ERs (b). Extraction conditions: solvent, methanol; solvent volume, 1 mL; extractant, [OMIM][Tf₂N]; extractant volume, 22 L; extraction temperature, 10°C, 20°C, 30°C, 40°C, and 50°C, respectively; ultrasonic time, 2 min, 5 min, 8 min, 11 min, and 14 min, respectively; centrifugal time, 5 min.

(a)

(b)