Evidence for Degradation of the Chrome Yellows in Van Gogh's Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron-Radiation-Based X-ray Techniques.
This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur-rich PbCr1-x Sx O4 (x≈0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., Cr(III) compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future.
CNR-ISTM and SMAArt Centre, Department of Chemistry, Biology and Biotechnologies, University of Perugia, via Elce di Sotto 8, 06123 Perugia (Italy). letizia.monico@istm.cnr.it.|Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium). letizia.monico@istm.cnr.it.
Letizia
L
Monico
Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium).
Koen
K
Janssens
Conservation Department, Van Gogh Museum, Paulus Potterstraat 7, 1070 AJ Amsterdam (The Netherlands).
Ella
E
Hendriks
Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium).
Frederik
F
Vanmeert
Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium).
Geert
G
Van der Snickt
ESRF, Avenue des Martyrs 71, 38000 Grenoble (France).|LAMS, CNRS UMR 8220, Sorbonne Universités, UPMC Univ Paris 06, place Jussieu 4, 75005 Paris (France).
Marine
M
Cotte
DESY, Notkestrasse 85, 22607 Hamburg (Germany).
Gerald
G
Falkenberg
CNR-ISTM and SMAArt Centre, Department of Chemistry, Biology and Biotechnologies, University of Perugia, via Elce di Sotto 8, 06123 Perugia (Italy).
Brunetto Giovanni
BG
Brunetti
CNR-ISTM and SMAArt Centre, Department of Chemistry, Biology and Biotechnologies, University of Perugia, via Elce di Sotto 8, 06123 Perugia (Italy).
Costanza
C
Miliani
X-ray absorption spectroscopy; dyes/pigments; lead chromate; photoreduction; vibrational spectroscopy