Rapid column chromatography separation of alkylnaphthalenes from aromatic components in sedimentary organic matter for compound specific stable isotope analysis

A rapid, small scale method for separating alkylnaphthalenes from aromatic fractions in sedimentary organic matter, named two-step column chromatography, is described using alumina as the stationary phase. The entire process operates using minimal amounts of solvents and alumina, with sample sizes of as little as 1 mg and a duration of 30 min. The results monitored by gas chromatography-mass spectrometry showed that clean alkylnaphthalenes and biphenyls can be obtained that are free of unresolved complex mixture (UCM), monoaromatics and triaromatics, which allows accurate measurement of compound specific stable isotope data. This method provides rapid sample processing suitable for routine analysis in organic geochemistry to better extract the geological and geochemical information carried by alkylnaphthalenes in sedimentary organic matter.