Abstract
In this study, we compare two methods which are used to detect five diphenylether herbicides. One is up-and-down shaker-assisted emulsion, the other is water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid–liquid microextraction (WLSEME). The first method cause the extraction solvent to form fine droplets in the sample solution by shaking violently. After optimization, this method can finish extraction in three minutes using only 30 μL of decyl acetate. The linear range is 2-1000 μg L-1 and r2 is greater than 0.9992; detection limit is from 0.62 to 1.74 μg L-1. The relative recoveries range from 90 to 102% for river water; 88–104% for lake water and 93–102% for irrigating water. The WLSEME method use a microsyringe to withdrew and discharge extraction solvent and 1 mg L-1 tween 60 (as the dispersed solvent) four times within 10 seconds. After that, a cloudy emulsified solution is formed in the syringe. The effect of various experimental parameters on extraction conditions were studied. The linear range is from 2 to 1000 μg L-1 for the target compounds, and the LODs are between 0.72 and 1.38 μg L-1. The relative recoveries range from 95 to 108% for river water; 96–109% for lake water and 86–114% for irrigating water.