Molecular Characterization of Adhesives (Glue Lining\nPastes) Used in Restoration

The\nmolecular characterization of samples from works of art can\nprovide valuable insights into the composition of ancient restoration\nmaterials and their conservation state. Here, we present a novel analytical\nprotocol for the molecular characterization of a specific adhesive\nused in historical painting restoration, known as “glue lining\npastes.” Due to the high molecular complexity of these adhesives,\nwe propose a multistep extraction protocol to recover and fractionate\nfrom a single microsample the three main classes of biomolecules contained\nin glue pastes (lipids, polysaccharides, and proteins). High-performance\nseparation coupled with high-resolution mass spectrometry (MS) techniques\nwere applied to the isolated fractions to identify specific components.\nThe proposed method was optimized using test specimens of various\ntraditional glue pastes applied to canvases and successfully applied\nto a historical glue paste sample from the 17th-century painting “<i>La fuga in Egitto</i>,” part of the <i>Pagliara</i> collection at the University Suor Orsola Benincasa (Naples, Italy).\nThe data collected in this work provide insights into the specific\nrecipe used for adhesive preparation, supporting artistic and historical\ninterpretations and contributing to a broader understanding of old\nrestoration practices. Data are available via ProteomeXchange with\nthe identifier PXD051480.