GC Determination of Phenols in Water with Liquid-phase Microextraction

A GC method for determination of microamounts of phenol pollutants in water with liquid-phase microextraction (LPME) to separate and enrich the phenols,was proposed.Various factors affecting the rate of extraction of LPME,including selection of solvent and amount of solvent required,rate of stirring,time of extraction,and acidity as well as the ionic strength of the extraction medium,were studied and the optimized conditions for LPME were summarized as follows:① toluene was chosen as solvent and 3.0 μL was used;② 4-nitrotoluene was used as internal standard;③ extraction was performed in a medium of pH 2.2,containing 200 g·L-1 NaCl,with stirring rate of 150 r·min-1 for 20 min.Linearity of working curves of phenol and chlorophenols were kept in the ranges of 0.02-20.00 mg·L-1 and of 0.02-10 mg·L-1 respectively.Recovery and precision of the method were tested on a lake water sampe,giving values of av.recovery and RSD (n=7) of 93.7% and 6.3% respectively.Detection limit (3S/N) of this method was found to be 0.01 mg·L-1.