Lead soaps in paintings: symptoms and the role of humidity

0538352 - ÚACH 2022 RIV CZ eng C - Conference Paper (international conference)
Garrappa, Silvia - Švarcová, Silvie - Kočí, Eva - Hradilová, J. - Bezdička, Petr - Hradil, David
Lead soaps in paintings: symptoms and the role of humidity.
Prague: Academy of Fine Arts in Prague, 2020. ISBN 978-80-88366-14-0. In: ACTA ARTIS ACADEMICA 2020 : The Colour Theme. Prague: Academy of Fine Arts, 2020 - (Hradil, D.; Hradilová, J.; Švarcová, S.; Kočí, E.), s. 55-68. ISBN 978-80-88366-14-0.
[Interdisciplinary ALMA Conference /7./. Bratislava (SK), 16.10.2019-18.10.2019]
Grant - others:AV ČR(CZ) StrategieAV21/6
Program: StrategieAV
Institutional support: RVO:61388980
Keywords : lead soaps * paintings * oil * egg yolk * humidity
OECD category: Analytical chemistry

In this study, an overview of the symptoms of lead soaps reported in artworks in combination
with the study of the role of humidity on the formation of these degradation products have
been thoroughly investigated. The use of optical microscopy, scanning electron microscopy
(SEM) in combination with Fourier-transform infrared spectroscopy (FTIR) proved to be an
efficient analytical approach to highlight both the saponified area of artworks’ samples and the
formation of metal carboxylates within mock-up model systems. Optical microscopy revealed
to be very useful for the first screening of samples embedded in resin, while SEM helped in
the detection and distribution of elements within the cross-sections. On the other hand, FTIR
microscope proved to be a very powerful instrument for high-resolution point measurements
performed in the attenuated total reflection mode (ATR) mode with mercury-cadmium-telluride
(MCT) detector, as well as for chemical imaging of larger area of both artworks’ and mock-up
samples performed in the ATR mode with focal plane arrays (FPA) detector. This study provides
new useful insights contributing to better understanding of factors affecting the paints‘ stability,
which is neccesary for developing new efficient strategies for preservation and restoration of
fatty-based painted artworks.
Permanent Link: http://hdl.handle.net/11104/0320105