Jana Sanyova | Royal Institute for Cultural Heritage, Brussels (IRPA / KIK) (original) (raw)

Papers by Jana Sanyova

Heritage science, Jun 19, 2024

Minerals

The paint materials and techniques of The Descent from Cross, a panel painting attributed to the ... more The paint materials and techniques of The Descent from Cross, a panel painting attributed to the Portuguese painter Francisco João (act. 1558–1595), were investigated with a combination of visible, ultraviolet, and infrared imaging and an analysis of paint samples with microscopic, spectroscopic, and chromatographic techniques. The colour palette is composed of lead white, lead–tin yellow, minium, vermilion, ochres of different colours, umber, smalt, azurite, verdigris, charcoal black, and a variety of different-coloured red lakes made of brazilwood and cochineal. An oil-based medium was identified. The characterisation of the pigment mixtures, paint build-up, and particular paint handling techniques enabled us to determine their role in the style and formal appearance of this painting and to discuss Portuguese painting practices in the larger context of 16th-century European painting. Mineral and elemental associations or impurities in the blue pigments, as well as degradation issu...

$Research paper thumbnail of Characterization of non-aged and aged modern Prussian Blue pigments by Mössbauer spectroscopy, x-ray powder diffraction and x-ray absorption spectroscopy$

Analytical and Bioanalytical Chemistry, Jun 16, 2011

Egyptian blue has been identified in a painting from 1524 by the Italian artist Ortolano Ferrares... more Egyptian blue has been identified in a painting from 1524 by the Italian artist Ortolano Ferrarese (Giovanni Battista Benvenuto). Egyptian blue is the oldest known synthetic pigment, invented by the Egyptians in the fourth dynasty (2613-2494BC) of the Old Kingdom and extensively used throughout Antiquity. From about 1000A.D., it disappeared from the historical record and was only reinvented in the late nineteenth and early twentieth century. The discovery of Egyptian blue in Ortolano Ferrarese's painting from 1524 shows that Egyptian blue was in fact available in the period from which it is normally considered not to exist. The identification of Egyptian blue is based on optical microscopy supported by energy-dispersive spectroscopy and visual light photon-induced spectroscopy, and finally confirmed by Raman microspectroscopy.

Anthocyanins are colorants that provide most of the blue, red and violet colours in numerous plan... more Anthocyanins are colorants that provide most of the blue, red and violet colours in numerous plants and fruits. Because of their great sensitivity to the slightest changes in pH and their instability in ordinary daylight, it is generally thought that these colorants were used only to dye everyday clothes in a domestic context. However, medieval artists' recipe books not only describe these elusive substances, but also indicate their use in illumination. This is notably the case for the texts of the so-called 'Strasbourg Tradition', written in the south of Germany and the north of France between 1400 and 1560, and partly composed from an older Alsatian treatise on illumination. Departing from these sources, this paper details the methods employed to prepare these colorants and (re)evaluates their diverse uses in painting and illuminating techniques. These technical data subsequently served as a basis upon which to make reconstructions. Finally, an attempt to correlate the information provided by these recipe books with specific artistic practices was carried out collating the descriptions with the results of analyses from contemporary illuminations by an Alsatian workshop active in the same geographical area.

Informes y Trabajos: Excavaciones en el exterior, 2015

espanolEl retablo de San Juan de la catedral de Santo Domingo de la Calzada es una obra cumbre de... more espanolEl retablo de San Juan de la catedral de Santo Domingo de la Calzada es una obra cumbre del estilo tardogotico, integrada por pinturas sobre tabla y esculturas policromadas, que sirvio de referencia a un nutrido grupo de artistas riojanos de la primera mitad del siglo XVI. El estudio riguroso por medio de metodos microscopicos analiticos y tecnicas instrumentales de identificacion elemental y molecular (espectroscopicas y cromatograficas) fue efectuado en el laboratorio de analisis de materiales del IPCE para el asesoramiento cientifico de la intervencion sobre el retablo. La realizacion de estos trabajos contribuyo a determinar la ejecucion pictorica, diagnosticar las alteraciones, perdidas y adiciones existentes, asi como caracterizar y localizar los materiales en la pintura y la policromia. EnglishThe altarpiece of San Juan of the Cathedral of Santo Domingo de la Calzada is a masterpiece of late Gothic style, composed of panel paintings and polychrome sculptures, which served as a reference to a large group of La Rioja’s artists of the first half of the sixteenth century. The rigorous study through analytical microscopic methods and instrumental (spectroscopy and chromatography) techniques of elemental and molecular identification was performed in the Material Analysis Laboratory of the IPCE for the scientific advice of the intervention on the altarpiece. The completion of this work helped determine the pictorial execution, diagnose alterations, losses and existing additions, as well as characterize and locate materials in painting and polychromy.

Contribution à l'étude de la structure et des propriétés des laques de garance (Unpublished docto... more Contribution à l'étude de la structure et des propriétés des laques de garance (Unpublished doctoral dissertation). Université libre de Bruxelles, Faculté des sciences appliquées-Chimie, Bruxelles.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Mar 1, 2017

In an investigation of the artists' materials used by P. S. Krøyer the contents of the tube colou... more In an investigation of the artists' materials used by P. S. Krøyer the contents of the tube colours found in Krøyer's painting cabinet were examined. In most cases, the results of the pigment analyses were as expected based on our knowledge of artists' colours used in the late 1800s and early 1900s. However, in one of the tube colours labelled "Jaune de Cadmium Citron" (cadmium lemon yellow) an extremely rare cadmium chromate pigment was found. The pigment was analysed and characterised by Raman microscopy (MRS), scanning electron microscopyenergy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), powder X-ray diffraction (PXRD), single-crystal X-ray crystallography, and electron paramagnetic resonance (EPR) spectroscopy. Cadmium chromate was synthesised by precipitation from an aqueous solution of cadmium nitrate and potassium chromate, and the resulting yellow crystals proved identical to the pigment found in the tube colour "Jaune de Cadmium Citron". The structure determined by single-crystal X-ray diffraction identified the pigment as 2CdCrO 4 •KOH•H 2 O or more accurately as KCd 2 (CrO 4) 2 (H 3 O 2) illustrating the μ-H 3 O 2 species. The yellow colour of the paint sample taken from the tube had a greenish hue, which became even more prominent upon storage and drying. EPR analysis of the sample showed the presence of paramagnetic degradation products containing Cr(III) and Cr(V).

Journal of Raman Spectroscopy, May 30, 2016

Raman spectroscopy is a powerful technique for the characterization of materials and is of valuab... more Raman spectroscopy is a powerful technique for the characterization of materials and is of valuable use in archaeometrical research in general. Green compounds of natural or synthetic origin are found in many research areas, ranging from mineralogy, to pigment identification, to corrosion studies. However, a detailed and comprehensive database of spectra and references is still missing in the literature. This paper provides both, a literature review and downloadable Raman spectra of reference products, to the researcher dealing with green materials in cultural heritage. Moreover, it tackles nomenclature issues. The collected spectra are discussed in relation to the preliminary/commercial identification of the material itself and to the published data. Practical aspects regarding the laser wavelength selection are also discussed with regards to the comparison to published reference spectra.The range of studied green materials is wide and encompasses Cu containing compounds (natural and synthetic, more or less known as pigments or degradation products, including polymorphs of the same formula), Fe based (green earths and synthetic organic pigments), modern Cr and Co green pigments.This approach is illustrated by analysing a cross section of a green zone of the Early Netherlandish panel painting ‘Ghent Altarpiece’ by the Van Eyck brothers. Copyright © 2016 John Wiley & Sons, Ltd.

Journal of Cultural Heritage, Oct 1, 2006

A mild extraction approach using HF, a weak acid but a strong aluminum-complexing agent, was inve... more A mild extraction approach using HF, a weak acid but a strong aluminum-complexing agent, was investigated as an alternative to usual methods such as treatment by strong acid solutions (HCl or H2SO4) at high temperature, or methylation by BF3 in MeOH, for the extraction of alizarin and other colorants from their aluminum complexes in madder lakes. HF and HCl extractions

Heritage Science, May 11, 2018

An analytical study of the painted folding doors at Herlev Hospital in Denmark has been performed... more An analytical study of the painted folding doors at Herlev Hospital in Denmark has been performed in connection with the creation of new doors. The hospital which construction was completed in 1976 is one of the first polychrome hospitals in the world. The building has achieved international awareness not only as a piece of architecture but also as an artwork being the largest artistic decoration of a public space in Denmark. Besides the decoration of the walls and interior which colour scheme was designed by the Danish artist Poul Gernes, the hospital foyer includes 65 individual paintings and two painted folding doors, which were executed by Poul Gernes. The folding doors are the original doors from 1976 and have never been restored. The paint used for the decoration of the folding doors were analysed by micro-Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, micro-Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography-mass spectrometry. The results showed, that the variant colours were created by the use of a limited number of pigments and consist of a mixture of inorganic pigments and synthetic organic pigments. The detected pigments were chrome yellow, chrome orange/chrome red, PY3, PR3, PR122, PB15, and PV23. Titanium white (rutile) was found in all paint and preparatory layers, and it was used as both a whitening agent in mixtures with other pigment and a filler material in the paint. The study also shows how the decorations were created and it hence relates to other studies of wall paintings from that period giving useful information for future restoration issues about the possible pigments and binder used.

Journal of Molecular Structure, Aug 1, 2017

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate wit... more The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO 4 •K 2 O•3H 2 O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopyenergy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn 2 (CrO 4) 2 (H 2 O)(OH) or as KZn 2 (CrO 4) 2 (H 3 O 2) emphasizing the µ-H 3 O 2 − moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.

Analytical Chemistry, Jan 10, 2011

The painting materials of the Portrait of Nicolaes van Bambeeck (Royal Museums of Fine Arts of Be... more The painting materials of the Portrait of Nicolaes van Bambeeck (Royal Museums of Fine Arts of Belgium, Brussels, inv. 155) painted by Rembrandt van Rijn in 1641 has been studied using high resolution cluster-TOF-SIMS imaging. In the first step, a moderate spatial resolution (2 μm) was used to characterize the layer structure and the chemical composition of each layer on account of a high mass resolution. Then, in the second step, and despite a low mass resolution, the cluster primary ion beam was focused well below 1 μm in order to reveal smaller structures in the painting sample. The study confirmed the presence of starch in the second ground layer, which is quite surprising and, at least for Rembrandt paintings, has never been reported before. TOF-SIMS also indicated the presence of proteins, which, added to the size and shape of lake particles, suggests that it was manufactured from shearings (waste of textile manufacturing) of dyed wool, used as the source of the dyestuff. The analyses have also shown various lead carboxylates, being the products of the interaction between lead white and the oil of the binding medium. These findings considerably contribute to the understanding of Rembrandt's studio practice and thus demonstrate the importance and potential of cluster-TOF-SIMS imaging in the characterization on a submicrometer scale of artist painting materials.