Chromatographic analysis of phenobarbital and belladonna alkaloid combinations.

A partition column chromatographic technique is applied to the analysis of phenobarbital and the belladonna alkaloids as found in commercial tablets and elixirs. Separation is achieved on a Celite column in which the stationary phase is a 10 per cent solution of p -toluenesulfonic acid. Ether and chloroform elute phenobarbital and the alkaloid– p -toluenesulfonic acid complex, respectively. The isolated phenobarbital is determined spectrophotometrically, and the total belladonna alkaloids are measured colorimetrically by a modification of a published procedure. A study of the modifications is reported and statistically evaluated. Standard recoveries averaged 99.01 per cent for phenobarbital and 98.73 per cent for atropine sulfate.