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Pitch compounds are frequently identified inside archaeological ceramic vessels. As their presence might affect the permeation of oil or wine into the ceramic fabric, experiments were conducted in which the diffusion of lipids or polyphenols into pitched and non-pitched modern vessels was followed by chemical analysis. Results show that the polyphenols of wine can intrude into the ceramics even through a pitch layer. Consequently, the absence of polyphenols in archaeological sherds is not due to their inability to reach the ceramic matrix under the pitch layer. By contrast, a pitch layer is quite effective to avoid oil intrusion into the ceramic matrix. Thus, it seems logical that oil amphorae would have been coated with pitch at the inside prior to use. Experiments in which the pitched ceramic was simultaneously exposed to oil and wine, show that the wine makes the pitch more permeable for the lipid compounds. These experimental data are confronted with residue analysis results obtained on amphorae fragments excavated in Sagalassos, Turkey. Pitch and oil were frequently found together. Based on a polyphenol test, indications for wine storage could only be obtained for two vessels. Against this background, the possible uses of the Sagalassos amphorae are discussed, and the traditional association of pine pitch with wine storage in archaeological amphorae is critically assessed.

Burned greasy deposits were found inside shells of the large Nile bivalve Chambardia rubens, excavated in an eight- to tenth- century AD church of the Coptic monastery of Bawit, Egypt, and supposedly used as oil lamps. The residues were subjected to a combination of chromatographic residue analysis techniques. The rather high concentrations of unsaturated fatty acids, as analysed by gas chromatography (GC) in the methylated extract, suggest the presence of a vegetal oil. Analysis of the stable carbon isotopes (delta C-13 values) of the methyl esters also favoured plants over animals as the lipid source. In the search for biomarkers by GC coupled to mass spectrometry on a silylated extract, a range of diacids together with high concentrations of 13,14-dihydroxydocosanoate and 11,12-dihydroxyeicosanoate were found. These compounds are oxidation products of erucic acid and gondoic acid, which are abundantly present in seeds of Brassicaceae plants. Liquid chromatography coupled to mass spectrometry analysis showed low concentrations of unaltered triglycerides, but revealed sizeable amounts of triglycerides with at least one dihydroxylated acyl chain. The unusual preservation of dihydroxylated triglycerides and alpha,omega-dicarboxylic acids can be related to the dry preservation conditions. Analysis of the stereoisomers of the dihydroxylated fatty acids allows one to determine whether oxidation took place during burning of the fuel or afterwards. The results prove that the oil of rapeseed (Brassica napus L.) or radish (Raphanus sativus L.) was used as illuminant in early Islamic Egypt, and that not only ceramic lamps but also mollusk shells were used as fuel containers. ispartof: Analytical and Bioanalytical Chemistry vol:390 issue:2 pages:783-793 ispartof: location:Germany status: published

Three lipid analysis methods were applied to extracts of archaeological potsherds from the ancient city of Sagalassos, south-west Turkey. In the fatty acid methyl ester fraction, obtained by selective transesterification of acylglycerols, the ratio of methyl palmitate to methyl stearate was determined. Secondly, by means of gas chromatography‐ combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS), stable carbon isotope ratios were measured for the same methyl esters. Finally, triglyceride composition was determined via high-performance liquid chromatography‐mass spectrometry (HPLC‐MS). All three methods can be used to trace the origin of animal fat. Agreement between them is reasonable, especially in recognizing ruminant adipose fat. One sample was found to be of dairy origin using both GC‐C‐IRMS and HPLC‐MS. The advantages of the various methods are discussed. Variations in lipid composition were observed between samples from different periods and excavated in diverse areas within the city of Sagalassos.