1961 年 81 巻 2 号 p. 164-165
Potentiometric titration of papaverine and narcotine was carried out by dissolving ca. 15mg. of the two alkaloids in acetone, methyl isobutyl ketone, or chloroform, and titrated with 0.005N p-toluenesulfonic acid in ethyleneglycol-isopropanol (1:1 mixture by volume). Jump in potential at the equivalence point was ca. 10mV./0.1cc. in chloroform and ca. 30mV./0.1cc. in acetone and methyl isobutyl ketone, from which it was learned that semimicro-potentiometric titration of papaverine and narcotine was possible by the use of the foregoing ketone solvent. Addition of phenol to the acetone solution makes it possible to carry out indicator titration by Methyl Orange. Good results were obtained by the use of this procedure for determination of the alkaloids in papaverine hydrochloride injection (4% solution) and narcotine powder (10% of narcotine).