Elemental labeling for the identification of proteinaceous-binding media in art works by ICP-MS

Abstract

In the history of art, artists have used many different organic compounds to dissolve pigments and apply them onto a support to obtain a paint layer. Proteins were used with success from the Middle Ages up to the Renaissance, and the traditional protein sources were animal parts (skins, tendons and bones) or milk and eggs. Moreover, some of these materials are commonly used as adhesive. In this paper, the first application of the metallomic analytical technique to the identification of proteins in artworks is reported. Samples were derivatized with DTPA/Eu and the derivatization procedure was evaluated by matrix-assisted laser desorption/ionization time-of-flight before high performance liquid chromatography inductively coupled plasma MS analysis. This study has been carried out on laboratory models prepared in-house for method development, resulting in the correct identification of the different classes of proteinaceous binders typically used. In addition, some unknown paint layer samples have been analyzed demonstrating that the method is applicable to very small sample amounts (0.6 mg), which are compatible with the amount normally available for this kind of analysis. The results obtained demonstrate the effectiveness of the method, suggesting the potential future use as novel diagnostic tool in the scientific study of artworks.

Proteins in Art, Archaeology, and Paleontology: From Detection to Identification

“…338 Mainly used for quantitative studies in biological applications based on peptides 339−341 or proteins, 342 the technique was evaluated for the characterization of proteinaceous binders in artwork. 343 Model binders based on egg, glue, and casein were studied. In particular, protein labeling was performed with DTPA and chelation with europium.…”

Atomic spectrometry update. Elemental speciation review

“…This approach has been applied to a variety of research areas including: the measurement of peptides, proteins and antibodies in a range of applications including biomedical science, 252 medicine 253 and art conservation. 254 The strategies, methods and chelators employed to label biomolecules such as proteins, peptides and antibodies have started to be investigated and optimised. A group from NIST 255 evaluated the use of microwave energy when metal-labelling peptides for measurement by RP HPLC-ICP-MS. A microwaveassisted lanthanide labelling procedure was developed and applied to derivatise the peptides angiotensin I and II, and bradykinin, using the macrocyclic bifunctional chemical chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), which signicantly improved the lanthanide labelling yield and reduced reaction times compared to bench top labelling procedures.…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…102 Metallomics is widely used for the study of metals in biological samples. In one novel piece of work, Crotti et al 103 applied metallomic analysis to the identification of proteins in artworks.…”