Emission of reactive oxygen species during degradation of iron gall ink

Iron gall inks are characterised by high contents of acids and transition metals, promoting degradation of cellulose due to hydrolysis and oxidation, respectively. Their chemical interaction with the environment is not well understood, especially in view of emissions of degradation products which could lead to spread of degradation processes. In order to study the emissions, we employed gas chromatography / mass spectrometry following headspace micro-extraction, and liquid chromatography following hydroxyl radical scavenging with appropriate probes. We also studied chemiluminescence of cellulose affected by ink degradation. We showed that while the emissions of organic volatile degradation compounds by inks are less intensive than those of surrounding paper, ink does promote the M. Strlič, E. Menart, I. Kralj Cigić, G. de Bruin, J. Kolar, M. Cassar: “Emission of volatiles and reactive oxygen species during degradation of iron gall ink”, Polym. Degrad. Stab., 95 (2010) 66-71 2 degradation of cellulose across big distances (from object to object). We were able to link this to emission of reactive oxygen species, probably hydrogen peroxide.