A Modified Method for the Rapid Analysis of Long-Chain Alkanes and Neophytadiene from Tobacco

A rapid method for the analysis of aliphatic hydrocarbons and neophytadiene in cured tobacco was developed. Briefly, ground tobacco was extracted for 15 min with methylene chloride in a flask placed in an ultrasonic vibration bath, 3-Methyltricosane was added as the internal standard. The solution was filtered and the solvent removed. The sample was redissolved in hexane and chromatographed on a small silicic acid column. The hydrocarbonneophytadiene fraction that eluted with hexane was reduced in volume and analysed on a SE-54 wall-coated glass capillary column, which resolved and permitted quantitation of the normal, iso-methyl- branched, and anteiso-methyl-branched hydrocarbons. The analytical data obtained by this method were equal to those obtained by the conventional Soxhlet extraction procedure. Based on experience in our laboratory, analysis time was reduced about fivefold and isomeric hydrocarbons were resolved by capillary gas chromatography.