Thermally assisted hydrolysis and methylation pyrolysis - gas chromatography / mass spectrometry for the chemical characterisation of traditional and synthetic binders

A number of techniques have been proposed and used for identifying the various paint binders, adhesives and coatings found in works of art. However, none of these techniques alone has been shown to provide chemical characterization of both fresh and old, traditional and synthetic materials. Thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry (THM-GCMS) has been used previously in the analysis of traditional oils, natural resins and freshly dried alkyds. This article presents some of the results of research, which aims to assess thoroughly the potential of THM-GCMS as an efficient, allround technique for the detailed analysis of a wide range of relevant organic materials. It presents THMGCMS results from the analysis of standards, of paint samples from Picasso’s Weeping Woman and Duchamp’s Fountain and of an adhesive from an Egyptian sculpture. In addition, some comments and recommendations on THM-GCMS working procedures are provided.