Gas chromatographic mass spectrometric approach to the problem of characterizing binding media in paintings

A GC-MS method is proposed for the characterization of binding media in paint works of art. The basic methodology relied on the determination of amino acids and fatty acids after hydrolysis with HCl and derivatization with 2-propanol and trifluoroacetic anhydride, and on the comparison with reference materials. The use of fused-silica capillary columns coated with methylphenylsilicone phases allowed to separate amino acid and fatty acid derivatives in a single analytical run. The method was applied to identify binding media used in ground and paint layers of polychrome sculptures of the eighteenth century.