非水溶液滴定による医薬品の定量 (第6報)

Abstract

Morphine, its derivatives, and their acid salts can be titrated in anhydrous acetic acid with perchloric acid by glass-calomel electrode potentiometrically or with crystal violet as the indicator. Morphine and its derivatives can be determined accurately by the basicity of the methylamino group, and their hydrochloride can also by titrated with same accuracy by adding mercuric acetate more than the equivalent of the sample and the excess of mercuric acetate scarcely hinders the titration. The acidity of phosphoric and sulfuric acids partially augment that of anhydrous acetic acid, so that the determination of the phosphates and sulfates are not very accurate. Codeine sulfate can be titrated one mole as one equivalent, because the first dissociation of sulfuric acid is large, but the second is very small in anhydrous acetic acid. It is known from the titration curves, that the basicity of morphine, ethylmorphine, codeine, hydrocodeine, and 3, 6-diacetylmorphine is similar to each other, but that the basicity of thebaine is stronger than that in anhydrous acetic acid.