title: Phase-transfer catalytic determination of phenols as methylated derivatives by gas chromatography with flame ionization and mass-selective detection.
abstract: A convenient method for the GC determination of phenols as methylated derivatives is proposed, taking advantage of the beneficial features of phase-transfer catalysis (PTC). The optimal experimental conditions of pH, temperature, organic solvent, time of extraction-derivatization and amounts of the participating reactants and catalysts, were properly established. Several catalysts in soluble or polymer-bound form were tested. Most of them demonstrated appreciably high-performance characteristics but the polymer-bound catalyst is most favourable due to its facile separation from the rest of the reaction system after the extraction-derivatization. Interferences with the extraction and derivatization yield were not noticed. The chromatographic separation of 11 methylated derivatives of phenols was complete within 23 min. The detection limits of the method, which range from 0.005 to 0.120 microg, are inadequate for drinking water analysis. However, the method was successfully applied to the analysis of fortified composite lake water samples using GC-flame ionization detection and GC-MS in the single ion monitoring mode with the most abundant characteristic ions. Spiked recoveries of phenolics were in the range 94-102%, on the basis of distilled water calibration graph, signifying that PTC determination of phenols is not affected by the composition of such matrices.
authors.affiliation: University of Ioannina, Department of Chemistry, Ioannina 451 10, Greece.
authors.forename: Yiannis C
authors.initials: YC
authors.lastname: Fiamegos
authors.forename: Christos G
authors.initials: CG
authors.lastname: Nanos
authors.forename: George A
authors.initials: GA
authors.lastname: Pilidis
authors.forename: Constantine D
authors.initials: CD
authors.lastname: Stalikas
mesh_terms: D002384:Catalysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008745:Methylation; D010636:Phenols / Q000032:analysis*; D012680:Sensitivity and Specificity; D012997:Solvents
chemical_list: D010636:Phenols; D012997:Solvents