Application of Continuous-Flow Liquid Phase Microextraction to the Analysis of Phenolic Compounds in Wastewater Samples

A novel method for the determination of phenolic compounds (phenol, o-cresol, m-cresol, 2,4-dimethylphenol, 2,3-dimethylphenol and 3,4-dimethylphenol) in water samples was developed by combined continuous-flow liquid-phase microextraction (CFME) with gas chromatography-flame ionization detection (GC-FID). The effects of extraction solvent type and volume, flow rate of sample solution, extraction time, salt concentration and pH on the extraction performance were investigated and optimized. The calibration curves and analyses of real samples were obtained under the following conditions: 3.0 µL n-Amyl acetate, 1.5 mL min−1 flowing rate, 15 min extracting time and pH 1.5. The developed protocol was found to yield a linear calibration curve in the concentration ranged from 10 to 10000 µg L−1 for the target analytes, and the limits of detection ranged from 2.32 to 2.95 µg L−1. Good repeatabilities of extraction were obtained, with relative standard deviation (R.S.D.) values below 6.89%. The results demonstrated that the CFME followed with GC-FID is a simple and reliable technique for the determination of phenolic compounds in water samples.