Gas Chromatography - Applications > The Head space Analysis of Tobacco > Page 70

The procedure as outlined by Supelco Inc. is as follows. 1 g of tobacco (12% moisture) was placed in a 20 ml headspace vial and 3.0 ml of 3M potassium chloride solution added. The fiber was coated with polydimethyl siloxane (a highly dispersive adsorbent) as a 100 mm film. The vial was heated to 95˚C and the fiber was left in contact with the headspace for 30 min. The sample was then desorbed from the fiber for one minute at 250˚C.


Courtesy of Supelco Inc.


Figure 45 A Chromatogram of Tobacco Headspace


The separation was carried out on a column 30 m long, 250 mm I.D. carrying a 0.25 mm thick film of 5% phenylmethylsiloxane. The stationary phase was predominantly dispersive with a slight capability of polar interactions with strong polarizing solute groups by the polarized aromatic nuclei of the phenyl groups. Helium was used as the carrier gas at 30 cm/sec. The column was held isothermally at 40˚C for one minute and the programmed to 250˚C at 6˚C/min. and then held at 250˚C for 2 min. It is seen that a clean separation of the components of the tobacco headspace is obtained and the resolution is quite adequate to compare tobaccos from different sources, tobaccos with different histories and tobaccos of different quality.