Trace analysis of endogenous and exogenous biomolecules from archaeological skeleton materials

An analytical procedure was developed for the determination of pharmacologically active substances in archaeological skeleton materials. In comparative model studies, added ("spiked") test biomolecules of varying chemical behaviours were extracted from sample matrices and percentage of the analytes recovered were estimated using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC). For the sterols and steroids studied, several organic solvents were appropriate. Extraction yields for the alkaloid nicotine, representing non-endogenous basic agents, were increased by alkalizing with triethylamine or by extracting with a two-phase system consisting of an alkaline aqueous and an organic layer (toluene). The flavonol quercetin was extractable only in an acidic environment. In a screening for native biomolecules using GC/MS, nicotine was identified in individual samples, in addition to lipophilic substances such as the endogenous cholesterol and its degradation products and two phytosterols which may have migrated into the bones from the surrounding soil.