Mass spectrometry archaeological samples

In the present chapter, we first provide some general information concerning the chemistry of waxes and lipids currently encountered in various items from our cultural heritage and we detail the main protocols based on direct mass spectrometry that have been developed so far. We then discuss the mass spectra obtained by EI-MS on a range of reference substances and materials sampled from museum and archaeological artefacts. We then focus on the recent possibilities supplied by electrospray ionisation for the elucidation of the structure of biomarkers of beeswax and animal fats. 

Figure 4.1 Analytical strategy in which direct mass spectrometry analyses using either elec tron ionisation or electrospray are used for detecting and identifying lipid substances in archaeological and museum samples...

Results obtained by Direct Mass Spectrometry using the Electron Ionisation Mode on Archaeological Samples and Wax Sculptures... 

C. Mathe, J. Connan, P. Archier, M. Mouton, C. Vieillescazes, Analysis of frankincense in archaeological samples by gas chromatography mass spectrometry, Annal. Chim., 97, 433 445 (2007). 

Gratuze, B., Blet-Lemarquand, M. and Barrandon, J.N. (2001). Mass spectrometry with laser sampling a new tool to characterize archaeological materials. Journal of Radio analytical and Nuclear Chemistry 247 645-656. 

In 1986, researchers at the Research Laboratory for Archaeology and the History of Art, University of Oxford, reported on how the radioactive carbon-14 isotope can be separated from other atoms in a sample by use of accelerator mass spectrometry, thus making it possible to derive more accurate chronologies from much smaller archaeological or anthropological specimens. For details, consult Hedges/Gowlett reference listed. 

Use of inductively coupled plasma-mass spectrometry (1CP-MS) coupled to a laser-ablation sample introduction system (LA-ICP-MS) as a minimally destructive method for chemical characterization of archaeological materials has gained favor during the past few years. Although still a relatively new analytical technique in archaeology, LA-ICP-MS has been demonstrated to be a productive avenue of research for chemical characterization of obsidian, chert, pottery, painted and glazed surfaces, and human bone and teeth. Archaeological applications of LA-ICP-MS and comparisons with other analytical methods are described. 

Inductively coupled plasma-mass spectrometry (ICP-MS) has been utilized as a bulk technique for the analysis of obsidian, chert and ceramic compositional analyses 12-14). However, due to the high level of spatial variation of ceramic materials, increased sample preparation is necessary with volatile acids coupled with microwave digestion (MD-ICP-MS) to properly represent the variability of ceramic assemblages IS, 16). Due to the increased sample preparation and exposure to volatile chemicals, researchers have continued to utilize neutron activation analysis (INAA) as the preferred method of chemical characterization of archaeological ceramics (77). 

Other analytical methods can also be applied for the detection of F in archaeological artefacts, especially when it is possible to take a sample or to perform microdestructive analysis. These are namely the electron microprobe with a wavelength-dispersive detector (WDX), secondary ion mass spectrometry (SIMS), X-ray fluorescence analysis under vacuum (XRF), transmission electron or scanning electron microscopy coupled with an energy-dispersive detector equipped with an ultrathin window (TEM/SEM-EDX). Fluorine can also be measured by means of classical potentiometry using an ion-selective electrode or ion chromatography. 

Techniques for analysis and sample preparation have been developed for using spark source mass spectrometry (SSMS) to study archaeological samples. Comparative studies of neutron activation and SSMS on identical samples have been made. The technique is used to determine the ores of origin of two series of early Peruvian artifacts. 

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