Simultaneous gas chromatographic analysis of lower fatty acids, phenols and indoles using a glass capillary column.

The simultaneous gas chromatographic separation of a mixture of 14 lower fatty acis, 11 phenols and 7 indoles has been effected by using a glass capillary column. Complete separation of the mixture has been obtained, except for phenol and o-cresol and o-ethylphenol and 3,5-xylenol whose peaks overlapped, and 2- and 3-methylindoles which were poorly separated. The optimum conditions are as follows: stationary phase, FFAP or PEG-20M; column (20 m X 0.28 mm I.D.) temperature, held for 1 min at 145 degrees (FFAP) or 130 degrees (PEG-20M); column oven, heated at 4 degrees/min from 145 or 130 to 180 degrees (FFAP) or 165 degrees (PEG-20M), maintained at 180 or 165 degrees for 30 min; carrier gas (helium) flow-rate, 0.6 ml/min (FFAP), 1.3 ml/min (PEG-20M); flame ionization detector. The method has been applied to the analysis of lower fatty acids, phenols and indoles in Japanese cigarette smoke, where the peaks were identified by the disappearance method using an alkaline pre-column.