Wen Mengliang

Microdetermination of alkaloids in organic solvents by potentiometric titration

Abstract A small-intefacial voltaic cell (antimony scratch) is shown to be satisfactory for end-point detection in titrations of various alkaloids and other basic drugs and their salts in ethanol, chloroform or dibutyl ether media with picric acid in the same medium. Small (0.4–4 mg) amounts can be determined. This method has the advantages of being simple and rapid with sharp end-points. The recoveries were 96.52-100.8% for the determinations of 19 drugs and their salts. The relative error was ±5% for five pharmaceutical tablets and injections.

Potentiometric titration of milligram amounts of organic acids with an interfacial voltaic cell for end-point detection

Abstract A small interfacial (antimony scratch) cell is shown to be satisfactory for indicating end-points in microtitrations of 28 organic acids, as well as pharmaceutical preparations. The method is simple and rapid and end-points are sharp. Recoveries were 98.0–101.9% for sample weights of 0.6–4 mg.