Estimating Vapor Pressure Data from Gas–Liquid Chromatography Retention Times: Analysis of Multiple Reference Approaches, Review of Prior Applications, and Outlook

Reliable methods for determining the vapor pressures of organic materials are of increasing importance as a tool for predicting the behavior and fate of chemicals that are introduced into the environment. In the present work, we analyze the method that relates the gas–liquid chromatography (GLC) retention data, namely, the retention factors (k) of selected organic compounds with their vapor pressures (p⁰) using multiple reference standards. Temperature-dependent k values of test chemicals and an adequate number y of reference standard chemicals having directly measured vapor pressure values at temperatures corresponding to GLC measurements are required to apply this method (GLC-RTyS). Retention data of 49 test compounds including a series of alkanes, alkanols, alkyl benzenes, phenols, some (hydro)­naphthalene derivatives, and menthol determined on a low-polar dimethylpolysiloxane (HP-1) column at a temperature range from 353 K to (403 or 423) K were used for method validation. We present a first systematic analysis aimed at examining whether and to what extent the selection of experimental conditions might influence/improve the results. Furthermore, we present a review of an alternative multireference correlation gas chromatographic (CGC) method that employs significant extrapolations and is based on the use of adjusted retention time t′ instead of k in order to reveal uncertainties inherent in routine application of this method.