Non-invasive Investigations of Paintings by Portable Instrumentation: The MOLAB Experience

Abstract

The in situ non invasive methods have experienced a significant development in the last decade because they meet specific needs of analytical chemistry in the field of cultural heritage where artworks are rarely moved from their locations, sampling is rarely permitted, and analytes are a wide range of inorganic, organic and organometallic substances in complex and precious matrices. MOLAB, a unique collection of integrated mobile instruments, has greatly contributed to demonstrate that it is now possible to obtain satisfactory results in the study of a variety of heritage objects without sampling or moving them to a laboratory. The current chapter describes an account of these results with particular attention to ancient, modern, and contemporary paintings. Several non-invasive methods by portable equipment, including XRF, mid- and near-FTIR, UV-Vis and Raman spectroscopy, as well as XRD, are discussed in detail along with their impact on our understanding of painting materials and execution techniques. Examples of successful applications are given, both for point analyses and hyperspectral imaging approaches. Lines for future perspectives are finally drawn.

Role of the Relative Humidity and the Cd/Zn Stoichiometry in the Photooxidation Process of Cadmium Yellows (CdS/Cd1−xZnxS) in Oil Paintings

“…Zn carboxylates have often been identified in oil paintings, with consequent negative effects on both the mechanical and aesthetical properties of the artworks. In hex‐CdS/thermal 95 %RH and cub‐CdS/thermal 95 %RH paints, the sensitivity of the reflection mode MA‐FTIR spectroscopy to the surface components, permitted us to reveal the presence of CdC 2 O 4 ⋅ 3 H 2 O as a degradation product (weak derivative‐like bands at 1310 and 785 cm −1 ; Figure S3 in the Supporting Information).…”

Complementary use of Optical Coherence Tomography (OCT) and Reflection FTIR spectroscopy for in-situ non-invasive monitoring of varnish removal from easel paintings

“…However, the development of additional analytical instruments that improve the evaluation of varnish removal is still highly encouraged amongst conservators. Within the joint research activities of the IPERION CH project [4] a specific task is dedicated to the development of non-invasive analytical methodologies, which, by combining different techniques currently available through the European mobile infrastructure MOLAB [5,6], would offer to conservators-restorers access to advanced chemical and physical information on the effect of solvent cleaning. As a result of this research, here an approach based on the integration of the stratigraphic information obtained from optical coherence tomography (OCT) with the chemical characterization of superficial layers accessible through reflection FTIR spectroscopy is presented and discussed.…”

EDXRF analysis of gold jewelry from the Archaeological Museum of Taranto, Italy

“…The non‐destructive and in situ analysis have experienced a significant development in the last decade because they meet specific needs of analytical methods in the field of cultural heritage and, especially, of goldwork …”

“…The non-destructive and in situ analysis have experienced a significant development in the last decade because they meet specific needs of analytical methods in the field of cultural heritage [7][8][9][10] and, especially, of goldwork. [11,12] In particular, three of these interesting samples, which highlight the presence of traces of polychrome and/or pasta vitrea, were studied to infer, through elemental analysis, the chemical composition of the polychrome and/or glazes used in the Hellenistic period and to deepen their realization techniques.…”