Direct exposure-(chemical ionisation)mass spectrometry for a rapid characterization of raw and archaeological diterpenoid resinous materials

摘要

Direct exposure chemical ionisation (isobu-tane) mass spectrometry (DE-CIMS) was examined for its suitability to quickly identify diterpenoid resinous materials in archaeological findings. The technique was tested on standard compounds and reference raw materials. It was found that DE-MS using chemical ionization by isobutane provided a mass spectral fingerprint of the organic material of the sample in just a few minutes. The main components were highlighted, thus allowing the identification of a diterpenoid resinous material from Pinaceae and to assess its degree of oxidation. Of particular interest was the possibility to distinguish between pine resin and pine pitch, which is not feasible with electron ionization at 70 eV. DE-(isobutane)CI was then successfully applied to a resinous archaeological substance sampled from the material contained in a Roman amphora (2nd-4th centuries AD) recovered from a waterlogged archaeological site in Liguria (Italy). The results prove the occurrence of a pitch from Pinaceae in the amphora.