MALDI‐FT‐ICR‐MS for archaeological lipid residue analysis

Abstract

Soft-ionization methods are currently at the forefront of developing novel methods for analysing degraded archaeological organic residues. Here, we present little-used soft ionization method of matrix assisted laser desorption/ionization-Fourier transform-ion cyclotron resonance-mass spectrometry (MALDI-FT-ICR-MS) for the identification of archaeological lipid residues. It is a high-resolution and sensitive method with low limits of detection capable of identifying lipid compounds in small concentrations, thus providing a highly potential new technique for the analysis of degraded lipid components. A thorough methodology development for analysing cooked and degraded food remains from ceramic vessels was carried out, and the most efficient sample preparation protocol is described. The identified components, also controlled by independent parallel analysis by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS), demonstrate its capability of identifying very different food residues including dairy, adipose fats as well as lipids of aquatic origin. The results obtained from experimentally cooked and original archaeological samples prove the suitability of MALDI-FT-ICR-MS for analysing archaeological organic residues. Sample preparation protocol and identification of compounds provide future reference for analysing various aged and degraded lipid residues in different organic and mineral matrices.

Combined use of gas chromatography and HPLC-ESI-Q-TOF to assess the culinary uses of archaeological Santa María style ceramic vessels from El Colorado (Catamarca, Argentina)

“…The characterization of intact TAGs with HPLC-ESI-Q-TOF in archaeological samples allowed us to (1) consider the preservation of lipid residues in samples, and (2) provide a first approach to the identification of TAG markers of original food sources. Moreover, this is the first study to characterize intact TAGs recovered from South American archaeological ceramics with HPLC-ESI-Q-TOF, while previous similar studies analyze European examples (Mottram et al 1997(Mottram et al , 2001Kimpe et al 2001Kimpe et al , 2004Mirabaud et al 2007;Romanus et al 2007;Garnier et al 2009;Saliu et al 2011Saliu et al , 2014La Nasa et al 2015;Tirat et al 2016;Degano et al 2016;van Dam et al 2017;Shevchenko et al 2017;Tuñón-López et al 2017;Oras et al 2017;Blanco-Zubiaguirre et al 2018;Lucejko et al 2018;Hammann and Cramp 2018).…”

“…Studies of archaeological lipids frequently comprise appropriate chemical treatment such as hydrolysis and derivatization for identification of fatty acids and sterols by gas chromatography-mass spectrometry (Vázquez et al 2008;Lucquin et al 2016;Bonaduce et al 2017, among others). Recently, different high-resolution mass spectrometry techniques have been successfully applied to the characterization of underivatized residual acylglycerides in objects of cultural heritage (Mottram et al 1997(Mottram et al , 2001Kimpe et al 2001Kimpe et al , 2004Mirabaud et al 2007;Romanus et al 2007;Garnier et al 2009;Saliu et al 2011Saliu et al , 2014La Nasa et al 2015;Tirat et al 2016;Degano et al 2016;van Dam et al 2017;Shevchenko et al 2017;Tuñón-López et al 2017;Oras et al 2017;Blanco-Zubiaguirre et al 2018;Lucejko et al 2018;Hammann and Cramp 2018). Considering that lipids in food sources are mostly in the form of triacylglycerides (TAGs), the advantage of studying non-decomposed TAGs in ceramic residues is that they can be more specific to the original source than their decomposition products.…”

A novel route for identifying starch diagenetic products in the archaeological record

“…Fortunately, new solvent classes have appeared in the last few decades, and ionic liquids have a wide range of customizable properties [ 77 ], suggesting this will be one route to explore as we seek a viable extraction protocol. Other routes will link imaging and advanced mass spectrometry systems, such as MALDI-FTMS approaches and derivatives [ 78 ]. While various methods will undoubtedly ensue, there is no current substitute for skilled archaeological insights to select appropriate settings and samples for biogeochemical and materials science examination.…”

The ARchaeological Organic residues Literature Database (AROLD): Construction of a tool for reviewing and querying published lipid data in organic residue analysis

“…Research based on soft ionization methods with high‐resolution mass spectrometry is interested in accurately determining triacylglycerol distribution when they are preserved for a more precise identification of animal fats (Mirabaud et al, 2007) or plant oils (Garnier et al, 2009; Oras et al, 2017; Saliu et al, 2014).…”