Abstract: Promethazine hydrochloride and chloropromazine hydrochloride were determined by oscillopolarographic titration with sodium tetraphenylborate(Na-TPB) as titrant. TPB gives a sharp oscillopolarographic incision in 0~5 mol/L NaAc-HAc(pH=5.4), which can be used to indicate the end point of the titration. The characteristics of the method are simple, quick and exact. The results are satisfactory.

Key words: oscillopolarography, sodium tetraphenylborate, titration, promethazine hydrochloride, chloropomazine hydrochloride