Evaluation of acidic paper deterioration in library materials by pyrolysis-gas chromatography

Pyrolysis-gas chromatography (Py-GC) has been applied to the evaluation of the deteriorated acidic paper in old books. A tiny piece (ca. 0.25 mg) of deteriorated paper was subjected to Py-GC measurement at 300 °C pyrolysis temperature. Levoglucosan and its dehydrated form levoglucosenone were typical degradation products while a recent control paper gave rise mainly to levoglucosan. The relative yield of levoglucosenone was much higher for the paper sample taken at the heavily deteriorated marginal part than that in the center of the same page of the old book. Accordingly, levoglucosenone observed in the pyrogram can be used as a marker to evaluate the degree of the deterioration of the acidic paper. The formation of levoglucosenone can be attributed to the slow deterioration process of paper, in which dehydration reaction play an important roll accompanied by the chain scission of cellulose. The Py-GC method for paper evaluation was also applied to clarify the effect of storage conditions and chemical compositions of paper materials to their deterioration processes.