ゼラチン溶液の銀電位滴定による不純物の検出

抄録

Many photographic gelatines are surveyed by silver electrae potentiometric titration with ammoniacal silver nitrate solution. Most gelatines except inert one showed inflextion or maximum and minimum points on their titration curves depending on their impurity cotents, and their potentials are very characteristic to each gelatine. An inert gelatine showed a similar titration curve as water which has neither inflexion nor maximum and minimum point. Thiosulfate added to an inert gelatine produces also a maximum and a minimum at a baser potential than other impurities. 0.2 g active S of thiosulfate in 100 kg gelatine is precisely determined by this method.