ORGANIC AND INORGANIC COMPONENTS OF MANUSCRIPT INKS

One of the most important causes of degradation in ancient manuscripts is the ink acidity. The relationship between the important corrosion that some inks provoke in the support and the fact that a strong black colouring remains in the ink has often been demonstrated By contrast, no acidity is shown in light coloured or slightly dark inks. Manuscri pt samples with iron gall inks were analysed by Gas Cromatography - Ma ss Spectrometry (GC/MS) and Scanning Electron Microscopy - Energy Disp ersive X-Ray Microanalysis (SEM-EDX). The samples, on paper and parchm ent bases, showed different colour and acidic behaviour. Inorganic ele ments analysed by SEM-EDX showed different sulphur and iron distributi ons on the base. The different ratio between the sulphur and the calci um was noted also. Gallic acid and sugars in the ink were tested by GC /MS. These compounds were identified by mass spectral analysis and co- injection of standard products. The results were different for light i nks and dark or acidic inks. The gallic acid remains only in the dark inks, but in the light and very acidic inks, gallic acid could not be found. Sugars that come from arabic gum were present in the light inks and in those dark inks that were not very acidic. The carbonized samp les retains very small amounts of sugars.