Determination of Diphenylether Herbicides in Water Samples Using Dispersive Liquid-Liquid Microextraction Combined...

Shaker-assisted dispersive liquid-liquid microextraction (SA-DLLME) and surfactant dispersive liquid-liquid microextraction (SDLLME) have been developed to determine five diphenylether herbicides in water samples using high-performance liquid chromatography with photodiode array detection (HPLC-PDA). For SA-DLLME, an up-and-down shaker-assisted emulsification was used. Extraction was complete in 3 min. Only 30 μL of decyl acetate was required, without a dispersive solvent. The linear range was from 2 to 1000 μg L-1, the coefficient of determination (r2) was better than 0.9992, and the limit of detection (LOD) was from 0.62 to 1.74 μg L-1. The relative recovery (RR) ranged from 90 to 102% for river water, 88 to 104% for lake water, and 93 to 102% for irrigating water. In SDLLME, a microsyringe was used to withdraw and discharge a mixture consisting of an extraction solvent and 1 mg L-1 Tween 60 as a surfactant four times within 10 s to form an emulsified solution. The linear range for the target compounds was from 2 to 1000 μg L-1. The LODs were between 0.72 and 1.38 μg L-1. The RR ranged from 95 to 108% for river water, 96 to 109% for lake water, and 86 to 114% for irrigating water.