Conversion of tobacco leaf constituents to total mainstream smoke polycyclic aromatic hydrocarbons

Conversion of Tobacco Leaf Constituents to Total Mainstream Smoke Polycyclic Aromatic Hydrocarbons 

Phytosterols Palmitic add Neophytadiene Polar fraction Alkaloids 

The PAHs identified in the various pyrolysates ranged in complexity from bicyclic (naphthalenes), tricyclic (acenaph-thenes, anthracenes, phenanthrenes), tetracyclic (pyrenes, fluoranthenes, chrysenes, benzanthracenes), pentacyclic (perylenes, benzopyrenes, dibenzanthracenes, benzofluoranthenes), hexacy-clic (dibenzochrysenes), and heptacyclic (coronene). Eventually, all the PAHs identified in the various pyrolysates were identified in mainstream CSC. In every case where the pyrolysis temperature was lowered, the yields of the PAHs in the pyrolysate also decreased (see Table XXV-6). 

From data they generated, Rayburn and Wartman (3091) and Rayburn et al. (3092) challenged the concept that the saturated aliphatic hydrocarbons in tobacco were precursors of the PAHs in mainstream CSC. Wynder and Hoffmann (4319,4332), in turn, criticized the experimental procedures that provided the data upon which Rayburn et al. based their argument  

In 1979, Severson et al. (3616), in their study of the petro-lenm ether extractables (8% of tobacco weight) chromato-graphically separated into eight fractions (see Table XXV-8), reported the identification of PAHs in the pyrolysate from fraction F-1, the fraction containing the saturated aliphatic hydrocarbons extracted from the tobacco. 

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