Determination of Phenolic Compounds in Wastewater by Liquid-Phase Microextraction Coupled with Gas Chromatography

Liquid-phase microextraction (LPME) coupled with gas chromatography-flame ionization detection is applied to the analysis of phenolic compounds (phenol, o-cresol, m-cresol, 2,4-dimethylphenol, 2,3- dimethylphenol, and 3,4-dimethylphenol) in water samples. Experimental parameters affecting the extraction efficiency (including extraction solvent and drop volume, stirring rate, extraction time, temperature, salt concentration, and pH) are investigated and optimized. The developed protocol yields a good linear calibration curve from 5 or 20 to 10000 microg/L for the target analytes. The limits of detection are in the range of 0.94 to 1.97 microg/L, and the relative standard deviation is below 9.37%. The established method is applied to determine the phenolic pollutants in real wastewater samples from a coking plant. The recoveries of the phenolic compounds studied are from 92% to 102%, suggesting the feasibility of the LPME method for the determination of the phenolic compounds in wastewater.