Supercritical Fluid Chromatography and Supercritical Fluid Chromatography/Mass Spectrometry for Analysis of Complex Hydrocarbon Mixtures

Abstract

Supercritical fluid chromatography (SFC) and SFC/mass spectrometry (MS) techniques offer the potential of making major contributions to the analysis and characterization of complex hydrocarbon mixtures, particularly for compounds of higher molecular weight and greater polarity. The combination of a chromatographic separation method with MS detection provides a powerful analytical tool as evidenced by the dominance of gas chromatography (GC)/MS for the characterization of amenable compounds. The favorable physical properties and high solvating powers of supercritical fluids allow separation of many compounds that are generally reserved for liquid chromatography (LC) owing to either thermal lability or insufficient volatility, with chromatographic resolution and efficiency per unit time approaching that of GC. These properties also allow successful interfacing to MS. Both capillary column and microbore column SFC/MS interfacing methods are described, and the advantages and limitations of each method are defined. Selected examples illustrating these methods for the characterization of complex hydrocarbon mixtures are also presented.