Indirect Determination of Vapor Pressures by Capillary Gas鈥揕iquid Chromatography: Analysis of the Reference Vapor-Pressure Data and Their Treatment

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• 作者：Kv臎toslav R暖啪i膷ka ; Bohum铆r Koutek ; Michal Fulem ; Michal Hoskovec
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2012
• 出版时间：May 10, 2012
• 年：2012
• 卷：57
• 期：5
• 页码：1349-1368
• 全文大小：807K
• 年卷期：v.57,no.5(May 10, 2012)
• ISSN：1520-5134

文摘

Knowledge of low vapor pressures p⁰ is indispensible for modeling the fate of chemicals in the environment as well as for other important applications. The indirect determination of vapor pressures by the capillary gas鈥搇iquid chromatography鈥搑elative retention time (GLC鈥揜T) technique has attracted the attention of many research groups, and two review papers devoted to this topic have already been published. To complement these reviews, the quality of the literature vapor pressures for reference compounds is analyzed, along with the influence of the equations used for the temperature dependence of p⁰ and the effects of the extrapolation interval applied. Since the GLC鈥揜T techniques yield p⁰ of subcooled liquid even in the case of solid samples, different approaches employed for the recalculation of solid vapor pressures for reference compounds to the values for subcooled liquids are discussed. It is shown that a selection and/or application of the physicochemical properties of the reference compounds can significantly influence the quality of the GLC鈥揜T based vapor pressures and, if improperly selected/applied, even lead to vague and physico-chemically groundless results. In an effort to allow potential users to make an informed decision about what reference data and/or methodology to use to improve the reliability of the GLC鈥揜T based vapor-pressure data, we present a set of recommendations and advisories for appropriate reference data use and manipulation.