Head space analysis is basically a technique where the vapors in the gas above, and in equilibrium with a solid or liquid is sampled, as opposed to sampling, solely, the solid or the liquid themselves. The advantage of this approach is that gas chromatography can be used as the analytical technique, as opposed to liquid chromatography, thus providing four to five orders of magnitude greater sensitivity.
This technique has been used to identify spoiled food, fragrances from botanical material, the determination of plasticizers in plastics and for forensic samples involving arson snuff. Its main component, nicotine is habit forming and other compounds produced by pyrolysis during smoking are carcinogenic and can cause a number of other health problems. Tobacco is an extremely valuable export in the United States despite the health concern, and its quality is carefully monitored. Tobacco can be flue cured, air cured, fire cured or sun cured, but the quality of the product can often be monitored by analyzing the vapors in the head space above the tobacco. The head space over tobacco can be sampled and analyzed using a Solid Phase Micro Extraction (SPME) technique.
Diesel is similar in chemical composition to kerosene and heating oil in that it is composed of aliphatic hydrocarbons that are obtained from the fractional distillation of crude oil. Diesel has a higher boiling point fraction and the distillation range is greater than that of kerosene and heating oil being composed of essentially C10 to C25 aliphatic hydrocarbons.
The use of these extremely sensitive laboratory techniques must be made carefully because of the consequence of o ...