PRELIMINARY-RESULTS FOR THE ANALYSIS OF LIPIDS IN ANCIENT BONE

Lipid extracts were prepared for a number of samples of modern and anc ient bones of humans and other animals (pig, cow, horse and whale). Al iquots of the total lipid extracts were trimethylsilylated and analyse d directly by gas chromatography (GC) and gas chromatography/mass spec trometry (GC/MS) without prior fractionation or purification. The anal ysis of archaeological bones and samples of adhering soil showed that contamination of the bone by migration of lipids from the burial envir onment was not a serious problem. Analyses of modern reference materia ls showed the lipid extracts of bone possessing adhering marrow fat to be dominated by acyl lipids, e.g. triacylglycerols and free fatty aci ds. In contrast the lipid extract of a sample of the modern cow bone w ith the marrow fat removed was dominated by cholesterol; acyl lipids w ere present at low abundance. The GC and GC/MS analyses of the ancient bones of varying age and context of recovery also showed only a very low abundance of acyl lipids. Most significant was the finding of an a ppreciable concentration (1.5-46.5 mug g-1) of cholesterol together wi th its diagenetic degradation products, in all the samples that were e xamined. The possibility of using the cholesterol (and its degradation products) as a palaeodietary indicator is discussed. Evidence is also presented for the occurrence of bacterial marker compounds in the bon e total lipid extracts.