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 i n paint works of art. The basic methodology relied on the determinatio n of amino acids and fatty acids after hydrolysis with HCl and derivat ization with 2-propanol and trifluoroacetic anhydride, and on the comp arison with reference materials. The use of fused-silica capillary col umns coated with methylphenylsilicone phases allowed to separate amino acid and fatty acid derivatives in a single analytical run. The metho d was applied to identify binding media used in ground and paint layer s of polychrome sculptures of the eighteenth century.