Nontargeted Pattern Recognition in the Search for Pyrolysis Gas Chromatography/Mass Spectrometry Resin Markers in Historic Lacquered Objects

Abstract

A differential expression analysis technology developed for linear modeling of gene expression data was used in combination with thermally assisted hydrolysis and methylation gas chromatography/mass spectrometry (THM-GC/MS) to support the analysis of lacquers and varnishes on historical objects. Exudates from tropical trees, such as Manila copal, sandarac, South American copal, and Congo copal, which were frequently used in finishing layers on decorative objects up to the early 20th century, were compared through this approach. Highly discriminating features indicate biomarkers that can help to identify copals in resinous lacquers. The approach allows new, more systematic ways for finding biomarkers in the analysis of lacquered objects of art and varnishes.

Headspace solid-phase microextraction comprehensive 2D gas chromatography-time of flight mass spectrometry (HS-SPME-GC × GC-TOFMS) for origin traceability of the genus Hymenaea resinites

“…Previous studies 30,31 provided the data analysis process of the amber extract compositions. The chromatograms for each sample were imported into the programme -The Automatic Mass Spectral Deconvolution and Identication System (AMDIS), which automatically deconvoluted the data to extract the pure component spectra while allowing for more accurate identication.…”

The search for organic compounds with TMAH thermochemolysis: From Earth analyses to space exploration experiments

“…TMAH-Py-GC/MS is a practical method for the characterization of ancient art works, especially the composition of lacquer, such as the black lacquers of 19th-century furniture [218], European lacquer [199], wooden chips [219], varnish [206,220,221], the paints of antiques, historical coatings on objects of art [222] and the organic matters of archaeological scenarios [79,223,224]. Lists of markers generated in this process could be added into a database to improve the interpretation of complex mixtures in lacquers and combined with other complementary techniques for the compositional analysis of coatings, lacquers, pigments and binders in different antique and ancient architecture.…”

Digging deeper - A new data mining workflow for improved processing and interpretation of high resolution GC-Q-TOF MS data in archaeological research

“…The converted dataset can be processed with various peak picking software tools, such as MZmine 19,21 , XCMS 20 , or OpenMS 25 . Due to its open-source modular framework, MZmine 2 has seen multiple extensions implemented by various different laboratories in the past years, which include feature detection algorithms [26][27][28] , molecular networking 29,30 , visualization techniques 31,32 , as well as compound identification algorithms 33,34 , making the overall toolbox almost ready for GC-TOF MS data mining of complex archaeological sample sets, as recently shown by Decq et al 35 . Since electron ionisation (EI) results in numerous fragments, which provide information about the molecular structure, spectra matching was the choice for compound identification.…”