Isotopic biomarker

Schouten, S., Klien, W.C.M., Breteler, K., Blokker, P., Schogt, N., Irene, W., Rupstra, I.C., Grice, K., Bass, M., and Damste J.S.S. (1998) Biosynthetic effects on the stable carbon isotopic compositions of algal lipids Implications for deciphering the carbon isotopic biomarker record. Geochim. Cosmochim. Acta 62, 1397-1406. 

The question of microbial sulphide weathering at vents is currently being seriously addressed by a variety of combined approaches, including textural and isotopic biomarkers, water-rock interaction experiments and in situ colonisation experiments (Edwards McCollom, 2001 Leveille Juniper, 2002 Leveille etal., 2002). Sulphide weathering may prove to be a quantitatively important, long-term biogeochemical process at mid-ocean ridges. 

Boeda et al. (1996) identified bitumen on a flint scraper and a Levallois flake, discovered in Mousterian levels (about 40 000 BP) at the site of Umm el Tlel in Syria. The occurrence of polyaromatic hydrocarbons such as fluoranthene, pyrene, phenanthrenes and chrysenes suggested that the raw bitumen had been subjected to high temperature. The distribution of the sterane and terpane biomarkers in the bitumen did not correspond to the well-known bitumen occurrences in these areas. In other studies of bitumen associated with a wide variety of artefacts of later date, especially from the 6th Millennium BC onwards, molecular and isotopic methods have proved successful in recognizing different sources of bitumen enabling trade routes to be determined through time (Connan et al., 1992 Connan and Deschesne, 1996 Connan, 1999 Harrell and Lewan, 2002). 

To develop a method to determine urinary biomarkers for benzoates. The method involves the use of gas chromatography-combustion-isotope ratio mass spectrometry. It is proposed that the procedure developed will allow differentiation of natural benzoates from synthetic ones. 

The haptophyte microalga Emiliania huxleyi produces biomarkers in the form of long-chain (C37, C38, and C39) alkenones (Brassell, 1993). Alkenones are well preserved in marine sediments and their molecular distributions and isotopic composition have been used to infer paleo-temperatures (Brassell, 1993) and pC022 values (Jasper et ak, 1994), respectively. Unsaturation patterns in the alkenone series are related to the growth temperature of the haptophyte algae that produce these compounds (Brassell et ak, 1986 Prahl and Wakeham, 1987), and hold great promise as indicators of absolute ocean paleotemperature. 

Mansuy et al. [97] investigated the use of GC-C-IRMS as a complimentary correlation technique to GC and GC-MS, particularly for spilled crude oils and hydrocarbon samples that have undergone extensive weathering. In their study, a variety of oils and refined hydrocarbon products, weathered both artificially and naturally, were analyzed by GC, GC-MS, and GC-C-IRMS. The authors reported that in case of samples which have lost their more volatile n-alkanes as a result of weathering, the isotopic compositions of the individual compounds were not found to be extensively affected. Hence, GC-C-IRMS was shown to be useful for correlation of refined products dominated by n-alkanes in the C10-C20 region and containing none of the biomarkers more commonly used for source correlation purposes. For extensively weathered crude oils which have lost all of their n-alkanes,it has been demonstrated that isolation and pyrolysis of the asphaltenes followed by GC-C-IRMS of the individual pyrolysis products can be used for correlation purposes with their unaltered counterparts [97]. 

Radke J, Bechtel A, Gaupp R, Piittmann W, Schwark L, Sachse D, Gleixner D (2005) Correlation between hydrogen isotope ratios of lipid biomarkers and sediment maturity. Geochim Cosmochim Acta 69 5517-5530... 

Sass E, Kolodny Y (1972) Stable isotopes, chemistry and petrology of carbonate concretions (Mishash formation, Israel). Chem Geol 10 261-286 Sauer PE, EgUnton Tl, Hayes JM, Schimmelmann A, Sessions AL (2001) Compound-specific D/H ratios of hpid biomarkers from sediments as a proxy for environmental and climatic conditions. Geochim Cosmochim Acta 65 213-222... 

Newer instrumental methods of potential utility in organic analysis of environmental and geological biomarkers are compound specific isotope analysis (CSIA) and carbon-14 dating with accelerator mass spectrometry (AMS). CSIA provides the carbon isotope composition of individual... 

Simoneit BRT, Atmospheric transport of terrestrial organic matter to the sea, in Volkman JK (ed.). The Handbook of Environmental Chemistry, Vol. 2, Part N, Marine Organic Matter Biomarkers, Isotopes and DNA, Springer Verlag, Berlin, 165-208, 2006. 

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