Separation of alkylphenols by gas chromatography

Abstract

The single-run separation of the mixture of twenty-two C0-C3 alkylphenols was investigated by capillary gas chromatography using polysiloxane (OV-1701) and three derivatized cyclodextrins as stationary phases. These derivatized cyclodextrins were hexakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-α-cyclodextrin (ASiMe), heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin (BSiMe) and octakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-y-cyclodextrin (GSiMe). The result showed that the separation of 2,4-dimethylphenol from 2,5-dimethylphenol was not achieved on OV-1701 column. When derivatized cyclodextrins were used as stationary phases, the best single-run separation was achieved on BSiMe column using a column temperature of 120 ºC for 11 min and then programmed from 120-180 ºC at 25 ºC/min. The mixture could be separated in 13 minutes. In addition, chromatograms showed acceptable peak shapes without any prior derivatization. Thermodynamic parameters described the interaction between analytes and the stationary phases were also determined. The interactions of analytes on column that contains cyclodextrin derivatives were in the order of GSiMe < ASiMe < BSiMe, respectively, and were stronger than on OV-1701 column.