Characterization of phenol and alkyl phenols in organic matrixes with monoethylene glycol extraction and multidimensional gas chromatography/mass spectrometry

The use of monoethylene glycol as an extraction medium for removing phenol and alkyl phenols in organic matrixes such as hydrocarbons is introduced and combined with a practical analytical multidimensional gas chromatography approach. The analytical approach has been successfully developed for the characterization of phenol, cresols, xylenols, and alkyl phenols like 4-ethylphenol and 2,3,5-trimethylphenol. The technique employs a single-step extraction of the analytes with monoethylene glycol and sonication, followed by multidimensional gas chromatography with mass spectrometry in selected ion monitoring mode for the detection and quantitation. Extraction efficiency of phenol approached 100% while cresols, xylenols, and 4-ethylphenol were 97% or higher and 2,3,5-trimethylphenol was better than 91% under the analytical conditions used. With the technique described, a complete analysis can be conducted in less than 16 min. Reproducibility of area counts at two levels, namely, 5 ppm_w and 50 ppm_w over a period of 2 days were found to be less than 4% (n = 20). The analytes of interest was found to be linear over a range from 100 ppb_w to 250 ppm_w with correlation coefficient of at least 0.999 and detection limit of 50 ppb_w. Spike recoveries from 500 ppb_w to 250 ppm_w for all analytes range from 96 to 102%.