摘要：The acid in paper of old books published from l886 to 1985 were determined with pH measurements using JIS and 0.1M KCl methods, and the non-aqueous solvent extraction of the acid with a liquid ion-exchanger such as Primene JMT - ethanol mixed solvent. The percent extraction of acid in the same paper samples is in the following order Primene JMT-ethanol > 0.1M KCl solution > water(JIS method) The result proved that one cannot completely extract all the acid in the paper sample with water. The quantitative extraction of hydrogen ions in papers can be possibly extracted with a non-aqueous solvent containing an ion-exchanger such as Primene JM-T in ethanol. We know that old papers are being destroyed by the acid which is produced in the paper due to the hydrolysis of the sizing materials such as aluminum sulfate on the pulp of wooden materials.
