The low concentration of hydrocarbons anticipated in pollution base-line and monitoring studies necessitates the development of analytical techniques for marine tissue sensitive at the sub-microgram per kilogram level. In addition it is important to know the extraction efficiency of the petroleum hydrocarbons from the tissue sample so that appropriate sample sizes can be used for the desired sensitivity levels. Furthermore, analytical methods that ultimately permit the identification of individual hydrocarbon components are desired. A method meeting these experiments has been developed. It utilizes dynamic headspace sampling (1) of the tissue homogenate to extract the volatile organic components, followed by liquid chromatographic (LC) separation of the biogenic components extracted, gas chromatographic quantitation and gas chromatographic-mass spectrometric identification of the petroleum hydrocarbons present in the extract.