The choice of extraction solvent is very important for a DLLME process in order to maximize the extraction efficiency and increase selectivity for the target compounds. In this case, the extraction solvent should have low solubility in water, high capability with the target analytes and be miscible with the dispersive solvent. Three commonly used solvents including dichloromethane, chloroform and carbon tetrachloride were examined as an extraction solvent. The result shows that only carbon tetrachloride can efficiently extract the desired analytes. So carbon tetrachloride was selected as an extraction solvent.