Study of Complex Organic Binding Media Systems on Artworks Applying GC‐MS Analysis: Selected Examples from the Kunsthistorisches Museum, Vienna

Abstract

Within the Kunsthistorisches Museum (KHM), Vienna, three off‐line GC‐MS analytical procedures for the identification of natural organic media have been refined, tested, and validated for the use in investigating original, historic works of art. The analysis of a sample from a Greek terracotta statue suggested that the white ground layer of the polychromy, still partly present today, contained a gum‐based binding medium. Furthermore, a procedure for the simultaneous analysis of oils, waxes and resins was applied to the identification of the composition of the varnish layer from the 16th century painting “Lucretia” by Jacopo Negretti (1480–1528). In addition, in a collaboration with the Department for Conservation and Restoration, University of Applied Arts, Vienna, a series of samples from paintings on wooden panels from the Buddhist temple complex in Nako, Himachal Pradesh, India, was investigated for the presence of proteinaceous binding media.

Analytical characterization of lacquer objects excavated from a Chu tomb in China

“…However, linseed oil -a typical drying oil -was also reported to be added to lacquer as a solvent (Niimura et al, 1999;Lu et al, 2006). Linseed oil was the most studied drying oil due to its use in western oil paintings (Scalarone et al, 2001;Pitthard et al, 2006;Bonaduce et al, 2009) and in the Byzantine art (Valianou et al, 2011). Those two oils can be clearly identified in a fresh state by its fatty acid composition using GC/MS: tung oil contains a large amount of a-eleostearic acid (C18:3c), but no linolenic acid (C18:3); while there is no a-eleostearic acid in linseed oil (Schönemann et al, 2006).…”

Capillary Electrophoresis as Analytical Method for the Characterisation of Natural Diterpenoid Resins in Artistic and Historic Works: A Comparison with Gas Chromatography

“…After evaporating the solvent at a Rotavapor, the residue was derivatized with TFTMAH as described in ref. [16] by adding 20 L MethPrepII, 14 L MeOH and 28 L toluene, sealing the vials properly and leaving them in the oven for 60 min at 60°C. After cooling to room temperature, the slightly yellow solutions were transferred into conical 300 l glass inserts and 1 L sample solution was injected (in the splitless mode) into the GC without dilution.…”

“…As for gas chromatography (GC) the analytes must be volatile, the polar resin acids are normally derivatized and converted into esters before analysis. GC separation has been combined with spectrometric detection methods like Fourier transform (FT) IR spectrometry [8] or mass spectrometry (MS) [8][9][10][11][12][13][14][15][16]. In pyrolysis GC-MS the native resin samples are thermally decomposed in the inlet of the chromatograph, and the resulting components are separated and detected then [12,17].…”

“…In pyrolysis GC-MS the native resin samples are thermally decomposed in the inlet of the chromatograph, and the resulting components are separated and detected then [12,17]. In direct temperature MS [15][16][17][18], pyrolysis MS [19,20] and MALDI-TOF MS [21] the according substances are introduced into the MS without preceding separation with GC. Other applied methods were thermo microscopy and FTIR spectrometry [14,22], FT Raman spectrometry [23] and micro-Raman spectrometry [24].…”

The identification of binding agent used in late Shang Dynasty turquoise-inlayed bronze objects excavated in Anyang

“…The technique of gas chromatography coupled to mass spectrometry (GC/MS) was used to identify binding media of drying oil, resin and wax in artworks or archaeological objects (Cappitelli et al, 2002;Challinor, 1996;Pitthard et al, 2006;Bonaduce et al, 2009). The GC/MS analytical procedure for the analysis of lipids is based on the transesterification of fatty acids and the determination of their relative ratios to identify particular lipids, while the analytical procedure for the analysis of resinous binding media is based on the esterification of resinous acids followed by the identification of particular resins according to their resinous acid methyl esters (Pitthard et al, 2010;Colombini and Modugno, 2009;Valianou et al, 2011).…”