The Simultaneous Analysis of Proteins, Lipids, and Diterpenoid Resins Found in Cultural Objects.

Abstract

We report a GC-MS method for the simultaneous analysis of proteins oil, and diterpenoid resins found in cultural objects. The method was initially designed for protein analysis of protenaceous paints and adhesives and involves acid hydrolysis as the first step. The amino acids in the protein hydrolysates, thus obtained, are treated with propan-l-ol/ hydrogen chloride and then pentafluoropropionic anhydride. The procedure was found also to yield the propyl esters of fatty acids derived from lipids and diterpenoid acids derived from natural resins, and thus allows the choice of a single method for the analysis of artists media which contain either oil s or proteins or mixtures of both proteins and oils or even resins. Thus natural mixtures such as egg yolk and also mixtures made by the artist such as animal glue/seed oil emulsions can be analysed. Coupled with FTIR analysis of paints and the staining of cross sections, to indicate layer structure the method can help to elucidate the paints and adhesives used by artists.

Analytical Approaches Based on Gas Chromatography Mass Spectrometry (GC/MS) to Study Organic Materials in Artworks and Archaeological Objects

“…In the last ten years some improvements in the analytical procedures used by the scientific community for the analysis of organic materials in art samples have been proposed [101,[138][139][140][141][142][143][144][145][146][147]. Particular focus has been on both understanding and removing analytical interferences caused by inorganic constituents [148][149][150] and on developing methods for the simultaneous detection of more than one class of organic materials in the same micro-sample [151][152][153][154][155].…”

Ageing behaviour and analytical characterization of the Jatobá resin collected from Hymenaea stigonocarpa Mart.

“…Analytical studies have been done which not only deal with the characterization of the resins but also with their photochemical or thermal degradation. They have been performed by means of gas chromatography-mass spectrometry (GC-MS) [15,[19][20][21][22][23], pyrolysis-GC-MS (Py-GC-MS) [24], thermally assisted hydrolysis and methylation-Py-GC-MS (THM-Py-GC-MS) [25][26][27][28][29] and online trimethylsilylation Py-GC-MS [17,[30][31][32].…”

GC/MS in the Characterisation of Protein Paint Binders

“…• Transformation of amino acids into their N-trifluoroacetyl methyl esters [30], their corresponding propyl esters [83], butyl esters [16,55] or N-pentafluoropropionyl n-propyl esters [84] requires two distinct reaction steps. First, methanol, propanol, butanol, or n-propanol is used for the esterification of the acidic functions, and subsequently the reagents and solvents are evaporated.…”