Characterization of lipids preserved in Roman cooking pots by gas chromatography -mass spectrometry (GC-MS) (original) (raw)
Related papers
Archaeometry, 2007
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.
ABSTRACT This research establishes a methodology for extracting fatty acid residue from archaeological pottery sherds in order to verify the use of the vessels and corroborate theories of seasonal migration through dietary habits. Pottery sherds from unidentified sections of the vessels were powdered and washed in solvent to withdraw the embedded fatty residue. Fatty acids are present as free fatty acids or tri, di or monoacylglycerols in all natural animal or plant food sources.
… of Chromatography A, 1999
A new method is described for distinguishing between animal fats preserved in ancient pottery. Analysis of lipid fractions from two morphologically distinct vessel types (lamps and ''dripping dishes'') using on-line gas chromatography-13 combustion-isotope ratio mass spectrometry (GC-C-IRMS) showed that they could be distinguished by plotting the d C 13 value for n-hexadecanoic acid against that for n-octadecanoic acid. The d C values obtained for modern reference fats from domesticated animals likely to have been important in antiquity showed the lamp extracts to correlate with ruminant animal 13 fat, such as sheep or cattle, whereas the ''dripping dishes'' had d C values similar to those of non-ruminant animal fat, such as pig. These findings were entirely consistent with distributional information obtained by GC and with positional isomer information gained from analysis of dimethyldisulphide derivatives of the monounsaturated fatty acids. The results indicate that GC-C-IRMS has considerable potential for the classification of animal fats absorbed in ancient pottery particularly where fatty acid distributions have been altered by degradation during vessel use or burial. d C values were also shown to be of value in detecting the use of vessels in the processing of animal products from more than one source.
Lipids in Archaeological Pottery: A Review on Their Sampling and Extraction Techniques
Molecules
Several studies have been performed so far for the effective recovery, detection and quantification of specific compounds and their degradation products in archaeological materials. According to the literature, lipid molecules are the most durable and widespread biomarkers in ancient pottery. Artificial ageing studies to simulate lipid alterations over time have been reported. In this review, specific lipid archaeological biomarkers and well-established sampling and extraction methodologies are discussed. Although suitable analytical techniques have unraveled archaeological questions, some issues remain open such as the need to introduce innovative and miniaturized protocols to avoid extractions with organic solvents, which are often laborious and non-environmentally friendly.
POTENTIAL OF LIPID ANALYSIS ON PREHISTORIC PORTUGUESE POTTERY
This projected was a pilot study aiming to assess the potential of lipid analysis on Portuguese archaeological pottery. Thirty potsherds were analysed from two Portuguese prehistoric ditched enclosures: Perdigões and Bela Vista 5. In order to analyse the potsherds through GC-MS, 2g of ceramic powder were drilled from each potsherd and from different sections of the same: rim; base and exterior wall. In total 40 samples were analysed and the results compared through site, type of vessel, ware and section of the vessel. From Perdigões about 1500µg of lipid per gram of potsherd were extracted and 821µg from Bela Vista 5. Several free fatty acids and other lipids were identified in the majority of the samples. Due to lipid degradation, modern contamination and peak ratio variability only the content of one potsherd was identified. The results from this project demonstrated that lipids can be extracted from Portuguese archaeological vessels; however, they also show that modern contamination and degradation are major problems for this kind of research.
This paper presents evidence for increased recovery of organic residues from archaeological pottery through use of a microwave-assisted liquid chromatography protocol. C 16:0 and C 18:0 saturated fatty acids were obtained from archaeological potsherds recovered from nine Neolithic settlements in the Middle East dating between 4700 and 7300 cal BC, including materials that had not produced evidence for the survival of any lipid species through use of 'conventional'solvent extraction techniques. Compound-specific isotopic analyses of C 16:0 and C 18:0 fatty acids in potsherd extracts subsequently revealed d 13 C/d 12 C compositions consistent with modern subcutaneous fats of wild boar and goats pastured on lands adjacent to the Jordan Valley, and residues from a modern pottery vessel used in the manufacturing of butter, cheese and yogurt in central Turkey. These results are presented as an illustration of capabilities of the microwave-assisted recovery protocol. The reclamation of saturated and unsaturated fatty acids from archaeological pottery fragments recovered from a number of the earliest ceramic horizons in the Middle East is herewith reported, and the extraction methods and instrumental analytical techniques are described.