INVESTIGADORES
LANTOS Irene Johanna
congresos y reuniones científicas
Título:
New insights into the characterization of lipids in pre-Hispanic ceramics by mass spectrometry techniques
Autor/es:
IRENE J. LANTOS; VALERIA P. CAREAGA; EVELYN L. BONIFAZI; DIANA M. CASTELLANOS RODRÍGUEZ; MARTA S. MAIER
Lugar:
Bilbao
Reunión:
Congreso; Technart 2017; 2017
Institución organizadora:
Universidad del País Vasco
Resumen:
The usual method of lipid analysis in archaeological samples involves hydrolysis and derivatization of lipids to obtain FAME (fatty acid methyl esters). Because fatty acids are unspecific biomarkers it is also necessary to study residuary acylglycerides which are better biomarkers of original source. In this study we carried out a multi-analytical approach based on the integration of three different mass spectrometric techniques: gas chromatography-mass spectrometry (GC/MS), high performance liquid chromatography-mass spectrometry (HPLC-MS) and elemental analysis-isotope ratio mass spectrometry (EA-IRMS) to characterize archaeological organic residues which provides relevant information on past human activities. This work focuses on the lipid profile analysis of organic residues from ceramic storage and service containers from archeological sites in Catamarca, Argentina. In addition reference samples of typical plants (maize, mesquite, chañar and mistol) and animal (llama, guanaco and ñandú) food resources rich in lipids were studied for comparative purposes.Results from GC-MS in archaeological samples indicated mixtures of plant and animal lipids, including odd carbon and branched fatty acids. Neutral lipid analysis showed presence of animal and/or plant sterols. Isotopic analysis indicated the presence of different mixtures of C3 and C4 plants lipids, and/or animal lipids. With HPLC-MS we identified intact mono-, di- and triacylglycerides (MAG, DAG, TAG) in the archeological samples. A comparison between TAG profile of reference and archaeological samples allowed us to identify TAG of vegetable origin and biomarkers of South American camelids fat. The latter are characterized by having in their structure an odd fatty acid, in agreement with data from GC-MS data. The occurrence of intact TAG with odd fatty acids, both in archaeological samples and camelid samples (guanaco and llama), suggest that these compounds are not the product of contamination or post-depositional microbial degradation.The statistical significance of the biomarkers obtained by the multi-analytical approach was estimated using multivariate statistical analysis (MCA and DA).Lipids in the archaeological samples are largely found as TAG (even unsaturated), proving exceptional preservation. The characterization of the lipid profile and the identification of biomarkers by a multi-analytical approach in these samples could be useful to know the use of these archaeological utensils. The characterization of the acylglycerides and fatty acids in the references samples allowed us to start the construction of a database of lipids from plants and animals native to the area under study.