Mass Spectrometric and Synchrotron Radiation based techniques for the identification and distribution of painting materials in samples from paints of Josep Maria Sert

Abstract

BackgroundEstablishing the distribution of materials in paintings and that of their degradation products by imaging techniques is fundamental to understand the painting technique and can improve our knowledge on the conservation status of the painting. The combined use of chromatographic-mass spectrometric techniques, such as GC/MS or Py/GC/MS, and the chemical mapping of functional groups by imaging SR FTIR in transmission mode on thin sections and SR XRD line scans will be presented as a suitable approach to have a detailed characterisation of the materials in a paint sample, assuring their localisation in the sample build-up. This analytical approach has been used to study samples from Catalan paintings by Josep Maria Sert y Badía (20th century), a muralist achieving international recognition whose canvases adorned international buildings.ResultsThe pigments used by the painter as well as the organic materials used as binders and varnishes could be identified by means of conventional techniques. The distribution of these materials by means of Synchrotron Radiation based techniques allowed to establish the mixtures used by the painter depending on the purpose.ConclusionsResults show the suitability of the combined use of SR μFTIR and SR μXRD mapping and conventional techniques to unequivocally identify all the materials present in the sample and their localization in the sample build-up. This kind of approach becomes indispensable to solve the challenge of micro heterogeneous samples. The complementary interpretation of the data obtained with all the different techniques allowed the characterization of both organic and inorganic materials in the samples layer by layer as well as to establish the painting techniques used by Sert in the works-of-art under study.

Fourier transform infrared spectroscopic study of rabbit glue/inorganic pigments mixtures in fresh and aged reference paint reconstructions

“…ATR, DRIFT, PAS spectroscopies, FT-IR microspectroscopy, etc.) ensures high versatility in investigating both organic and inorganic materials in Cultural Heritage, for several purposes, such as diagnostic [1][2][3][4][5][6] and localization of materials in paint cross sections [7][8][9][10][11][12]. Infrared spectroscopy is also a fundamental tool to investigate the degradation and ageing of organic materials in Cultural Heritage.…”

Investigation of the Cross-Section Stratifications of Icons Using Micro-Raman and Micro-Fourier Transform Infrared (FT-IR) Spectroscopy

“…54,55 The detection of saponified oil was achieved by the observation in the spectra of the stretching vibrations of the methylenes C-H bonds at $2926 and 2855 cm À1 , the oil carbonyl band at $1730 cm À1 , the carboxylate modes at $1575 and 1540 cm À1 and, finally, the weak C-O band at $1270 cm À1 . [42][43][44]56 It should be noted that the FT-IR results suggested the presence of saponified oil only in samples 2.3, 2.4, and 5.2 (Table IV). Consequently, an intentional and systematic saponification is unlikely for the objects of this study and the presence of bands related to carboxylates could be explained as a result of natural ageing and alteration of oil due to oxidation and water hydrolysis.…”

“…[57][58][59] The existence of shellac was denoted by the carbonyl vibrations, which appear as a doublet band around 1725 cm À1 (due to the ester) and 1710 cm À1 (due to the acid), the C-H stretching bands, which fall in positions similar to those of oil, at $2926 and 2855 cm À1 , and the weak C-O band at $1270 cm À1 . 56,60,61 The identification of tree resin was based on the emergence of the strong C-H stretching vibrations at $2934 and 2875 cm À1 , the strong carbonyl stretch at $1716 cm À1 , and the ester groups C-O mode at $1250 cm À1 . 60 For the latter case, it is worth noting that the C-H modes appear at slightly higher wavenumbers than those in the oils and shellac, because of the cyclic ring structure of the tree resin, while the carbonyl band shifts to lower frequencies, as expected.…”

Characterization of Zahari Zograph’s nave wall paintings in the church “The nativity of the virgin” of Rila Monastery (Bulgaria) by vibrational spectroscopy and SEM–EDX analysis

“…The band at 1560 cm −1 , which is the strongest in the whole spectrum, evidenced the presence of large amount of carboxylates which might be metal salts of fatty acids (fatty acid soaps) (Lluveras-Tenorio et al 2012;Otero et al 2014;Sotiropoulou, Papliaka, and Vaccari 2016), resin metal salts (resinates) (Conti et al 2014) and beeswax metal salts (wax soaps) (Cuní et al 2012). Noteworthy, the carbonyl band appeared at 1708 cm −1 with a shoulder around 1730 cm −1 .…”