Liquid Chromatographic Separation of Sediment, Rock, and Coal Extracts and Crude Oil into Compound Classes

A method is described for the rapid fractionation of sediment, rock, and coal extracts and crude oils into compound classes. The method is based on combined polarity/affinity chromatography of soluble organic matter. Five heterocompound fractions are obtained in addition to the conventional saturated and aromatic hydrocarbon fractions. Model compound studies show that those fractions are chemically well-defined. The applicability to a variety of geological materials is demonstrated by analyzing a North Sea crude oil and solvent extracts of Posidonia shale, coal, and recent lake sediment samples. Generally reproducibilities and linearities are satisfactory. The total recoveries vary between 76% and 57%, depending on the sample type. The method is shown to be well-suited for the bulk compositional characterization of soluble organic matter. Separations can be performed on both the analytical and the semipreparative scales. Isolated fractions are amenable directly or after derivatization to qualitative and quantitative analysis by gas chromatography and gas chromatography/mass spectrometry.