Nontargeted Pattern Recognition in the Search for Pyrolysis Gas Chromatography/Mass Spectrometry Resin Markers in Historic Lacquered Objects.

A differential expression analysis technology developed for linear modeling of gene expression data was used in combination with thermally assisted hydrolysis and methylation gas chromatography/mass spectrometry (THM-GC/MS) to support the analysis of lacquers and varnishes on historical objects. Exudates from tropical trees, such as Manila copal, sandarac, South American copal, and Congo copal, which were frequently used in finishing layers on decorative objects up to the early 20th century, were compared through this approach. Highly discriminating features indicate biomarkers that can help to identify copals in resinous lacquers.

Microplastic contamination in gudgeons (Gobio gobio) from Flemish rivers (Belgium).

Plastic pollution is continuously growing on a global scale and emerging as a major environmental hazard. Smaller-sized plastics, so-called microplastics (<5 mm), are considered as being omnipresent throughout the aquatic environment, yet freshwater ecosystems have received little attention so far and are still largely unstudied. Present study aims to expand the current knowledge on microplastics in freshwater systems by documenting the occurrence in the digestive system of fish from 15 rivers at 17 locations in Flanders, Belgium.

Development of a dedicated peptide tandem mass spectral library for conservation science.

In recent years, the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) on tryptic digests of cultural heritage objects has attracted much attention. It allows for unambiguous identification of peptides and proteins, and even in complex mixtures species-specific identification becomes feasible with minimal sample consumption. Determination of the peptides is commonly based on theoretical cleavage of known protein sequences and on comparison of the expected peptide fragments with those found in the MS/MS spectra.

Classification of protein binders in artist's paints by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry: an evaluation of principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA).

Proteomics techniques are increasingly applied for the identification of protein binders in historical paints. The complex nature of paint samples, with different kinds of pigments mixed into, and degradation by long term exposure to light, humidity and temperature variations, requires solid analysis and interpretation methods. In this study matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectra of tryptic-digested paint replicas are subjected to principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) in order to distinguish proteinaceous binders based on animal glues, egg white, egg yolk and milk casein from each other.

Tryptic peptide analysis of protein binders in works of art by liquid chromatography-tandem mass spectrometry.

A proteomics approach was used for the identification of protein binders in historical paints: the proteins were digested enzymatically into peptides using trypsin before being separated and detected by high performance liquid chromatography-electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS/MS). Mascot (Matrix Science) was used to analyse the resulting data and for protein identification. In contrast to amino acid analysis, amino acid sequences could be studied that retain much more information about the proteins.

Identification of protein binders in works of art by high-performance liquid chromatography-diode array detector analysis of their tryptic digests.

Proteins in works of art are generally determined by the relative amounts of amino acids. This method, however, implies a loss of information on the protein structure and its modifications. Consequently, we propose a method based on the analysis of trypsin digests using high-performance liquid chromatography (HPLC) UV diode array detection (DAD) for painting binder studies.