Investigation of Vaporization Enthalpies and Vapor Pressures of Organic Compounds by Correlation Gas Chromatography

Thermodynamic properties of organic compounds are useful to scientists and manufacturers in many areas of research and technology. This work focuses on measuring and reporting these properties on materials of commercial, environmental and scientific interest. Vaporization enthalpies and vapor pressures of several organic compounds have been studied using correlation gas chromatography (CGC) and are reported here as well as in recent publications. The CGC method allows for the indirect measurement of these properties in instances where these materials are available only in mixtures or in very small amounts. The qualities of these measurements for any chosen target are directly related to the quality of standards chosen. In some cases, no reliable standards are available that most closely represent the properties of a molecule of interest. In these circumstances, it is necessary to search and identify the appropriate structural features necessary to evaluate the targets of interest. One aspect of this work examined the structural features necessary to successfully evaluate both the vaporization enthalpy and vapor pressures of several sesquiterpenes, polycyclic natural products emitted by plants that are partially responsible for photochemical production of smog. Another aspect of this work evaluated both the vaporization enthalpies and vapor pressures of adamantane and diamantane, two substances causing depositional problems in natural gas pipelines from reservoirs that are hot. A third aspect evaluated these properties for a series of flavor ingredients used in foods. Included in this dissertation are values evaluated for the following additional substances; sesquiterpines : cedrol, E & Z nerolidol, , α & β cedrene, β caryophyllene, α bergamotene, α humulene; flavor ingredients: d carvone, β damascenone, geranylacetone, nerylacetone, β ionone, isophorone, cis jasmone, two isomers of isojasmone; and tentative evaluations for α tocopherol, and tetrahydrocannabinol