Vaporization Enthalpies and Vapor Pressures of 5α-Androstane and 5α-Cholestane by Correlation Gas Chromatography

Abstract

Vaporization enthalpies and vapor pressures of 5α-androstane and 5α-cholestane are reported using correlation gas chromatography (CGC). The results for 5α-cholestane are compared to both estimated and experimental values reported previously for 5α-cholestane. The results are generally in agreement with the literature within the reported uncertainties. A simple method for reducing the amount of curvature in logarithm plots of vapor pressures as a function of K/T when using n-alkanes as standards in CGC experiments is also reported. This may prove useful in evaluating vapor pressures of rigid hydrocarbons at high temperatures.

Keywords

• 5α-androstane
• 5α-cholestane
• vaporization enthalpy
• vapor pressure
• correlation gas chromatography