UMYMFOR   05516
UNIDAD DE MICROANALISIS Y METODOS FISICOS EN QUIMICA ORGANICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Study of Organic residues in archaeological ceramics by mass spectrometry
Autor/es:
BONIFAZI, EVELYN L.; MAIER, MARTA; CAREAGA, VALERIA P.; LANTOS, IRENE
Lugar:
Rio de Janeiro
Reunión:
Conferencia; 1st Ibero-American, 6th BrMass Conference on mass spectrometry; 2016
Institución organizadora:
Sociedade Brasileira de Espectrometria de Massas
Resumen:
The study at a molecular level of archaeological organic residues provides relevant information on past human activities. The organic compounds are absorbed into the porous matrix of ceramics in contact with food during cooking and / or storage, favoring an exceptional preservation of some types of compounds, such as lipids. The usual method of lipids analysis in archaeological samples involves hydrolysis and derivatization of acylglycerides and phospholipids to obtained FAME (fatty acid methyl ester). Then this is analyzed by GC and GC-MS. Because fatty acids are unspecific biomarkers it is necessary to study residuary acylglicerides and phospholipids which are better biomarkers of original source. This work focuses on the lipid profile analysis of organic residues from reference samples, replica and archeological ceramic vessels.It was required to carry out optimization and application of methodologies based on liquid chromatography-mass spectrometry (LC-ESI and LC-APCI) and tandem mass analysis. Total lipid were analyzed, samples were extracted with chloroform/ methanol (2:1) and injected directly into LC-MS (Bruker MicrOTOF-Q II).Four varieties of native Zea mays L. (Pisingallo, Chullpi, Dentado blanco and Capia) were characterized. Using these results as a reference, the lipid profiles of residues absorbed into fragments of replica and archaeological ceramics were characterized. The results showed the presence of tri- di- and monoacylglicerides, and phospholipids in the maize samples, with characteristic profiles of vegetable oils. It was observed that part of the lipids extracted from replica and archaeological ceramics were preserved as intact acylglicerides and degradation products as minor components. Hydroxylated acylglycerides derivatives and possible hydroperoxides species were identified as the main degradation products. Through high sensitivity and resolution of the technique used and the exhaustive tandem mass analysis it was possible to characterize the analyzed samples. The lipid profiles obtained contribute to our knowledge on diet and eating habits of past cultures.