1-Octyl-3- methyl imidazole hexafluorophosphate ([Omim]PF6) and 1-octyl-3-methyl imidazole tetrafluoroborate ([Omim]BF4) have been synthesized. Using 2-chlorophenol

4-chlorophenol

2

4-dichlorophenol and 2

4

6-trichlorophenol as reactants

Ultraviolet spectrum analysis (USA) as test method

ultrasonic oscillation as extraction method

the performance of extraction to different chlorophenols

the impact on extraction ratio by extraction temperature

time

phase ratio(VIL:VCP) and pH have been studied and the performance of reuse has also been discussed in this paper. It is concluded that the ionic liquids achieve the best condition with 15min

1:3(VIL:VCP) phase ratio

308 K and pH <5. Under the best condition

the extraction rates of [Omim]BF4 to 2-chlorophenol

4-chlorophenol

2

4-dichlorophenol

2

4

6-trichlorophenol are 97.60%

95.20%

99.40% and 87.20%

respectively. For [Omim]PF6

however

the extraction rates are 95.80%

92.20%

98.20% and 85.40%. The mechanism of extraction is also discussed in this essay. It is also showed that the extraction rate is rising with the increase of temperature by ultrasonic oscillation

which is different with magnetic stirring method.