Inadequate separation of saturate and monoaromatic hydrocarbons in crude oils and rock extracts by alumina column chromatography

When compared to the classical silica gel/alumina column chromatographic method, the neutral alumina procedure, recently validated for the isolation of organic nitrogen fractions from crude oils/rock extracts, appears to yield severely altered distributions for many classes of monoaromatic hydrocarbons in the aromatic hydrocarbon fraction. The potential analytical sequestration, if not recognized, could lead to erroneous geochemical interpretations.