Characterization of molecular biomarkers in peat samples by GC-MS

Abstract

The biomarker composition of peats in North Spain has been studied by gas chromatography and gas chromatography/mass spectrometry. We have identified n-alkanes and n-alkan-2-ones. The former compounds are more abundant in high boiling point regions with a strong odd over even preference. The second group also has a strong odd over even preference, the most abundant being the C27 n-alkan-2-one. These related compounds point to a predominant terrestrial input. Substantial amounts of hopanoids are also present in the sample. Two of the most abundant are the hop-22(29)-ene and hopenone isomers. Hopanoids are mainly derived from bacterial membrane lipids, through diagenetic processes involving biohopanoids (Innes et al., 1997). This study was carried out in order to obtain information about climatic changes 4000 years ago in the north of Spain.