roomtemperature study of iron gall ink impregnated paper degradation under various oxygen and humidity conditions timedependent monitoring by viscosity and xray absorption nearedge spectrometry measurements analytical chemistry pmany western manuscripts were written using iron gall inks these inks can damage the paper via two major mechanisms a acid hydrolysis enhanced by humidity and b oxidative depolymerization provoked by the presence of oxygen and free ironii ions the degradation of unsized whatman paper impregnated with different combinations of iron sulfate gallic acid and gum arabic was studied at room temperature in order to assess the relative importance of each mechanism the samples were stored in various environments including a dry andor an oxygenfree atmosphere the cellulose depolymerization was monitored by viscometry and related to changes in the oxidation state of iron determined by xray absorption nearedge spectrometry the results indicate that residual amounts of oxygen less than 01 promote cellulose depolymerization whereas the level of relative humidity has no impact the cellulose depolymerization also appears closely correlated to oxidative mechanisms regarding the oxidation of iron it only occurs in the simultaneous presence of oxygen and moisture suggesting the occurrence of rustlike oxidative mechanisms finally the presence of gallic acid has a strong influence which is only partially explained by its capacity to reduce ironiii to ironiip httpspubsacsorgdoiipdf101021ac1029242 83 101021ac1029242 veronique rouchon maroussia duranton cedric burgaud eleonora pellizzi bertrand lavedrine