Abstract: A new technique of end point indication in nonaqueous potentioroetric titration was presented. Acathode-ray oscillograph was used to replace the usual voltagemeasuring instrument. The sample was dissoved in the glacial acetic acid containing some acetic anhydride and mercury acetate and determined with 0.1 mol/Lperchloric acid standard solution, using microplatinum billet electrode as indicator electrode and calomel electrode as reference electrode. The sudden jumping of a fluorescent spot on the fluorescent screen indicates the end point of titration. This method of indication can response the transitory potential difference of two electrodes, the end point is directly visual and sensitive much better than the usual method. We have used this method to determine 11 organic basic drugs and obtained satisfactory results.

Key words: Nonaqueous oscillopotentiometric titration, Nonaqueous oscillopoten-tiometric titration of organic basic drugs