Polycyclic aromatic hydrocarbons in the environment. Isolation and characterization by chromatography, visible, ultraviolet, and mass spectrometry

Abstract

Polycyclic aromatic hydrocarbons from many sources accumulate in soils, recent and ancient sediments, and in many other environmental samples. They occur at low concentrations and in the presence of other extractable materials. We describe an isolation technique utilizing a sequence of gel filtration, adsorption chromatography, and charge transfer complexation. It leads rapidly to aromatic ring-type concentrates that are sufficiently pure for UV, visible, and mass spectrometry. In combination, these techniques resolve adequately very complex mixtures of aromatic hydrocarbons, for instance from fossil fuels, and provide a detailed insight into the hydrocarbon composition, on a milligram to microgram scale. Analyses of some recent near-shore marine sediments demonstrate an unanticipated complexity of the polycyclic aromatic hydrocarbon fraction. The principal hydrocarbon series extends over a wide molecular weight range; minor series are the naphthenologs and thienologs of the major series. The analytical and biochemical implications are discussed.