Abstract
The differential determination of aminopyrine and sulpyrin in pharmaceutical preparations were investigated. The determination is based on the principle that aminopyrine and sulpyrin are colored with ferric ferricyanate solution. Aminopyrine and sulpyrin were separated by treatment with chloroform because the former is soluble in chloroform while the later insoluble. Aminopyrine dissolved in 0.01% sulfuric acid solution after the evaporation of chloroform was colored with ferric ferricyanate. Sulpyrin insoluble in chloroform was hydrolyzed to monomethylaminoantipyrine, extracted with chloroform and treated in the same manner as aminopyrine. Each of the colored solutions obtained from the sample and the standard solution (aminopyrine or sulpyrin 10 μg/ml), after ethanol was added for the prevention of precipitation of the pigment, were allowed to stand for about 60 minutes at 20∼30° and then determined respectively at 710 mμ. The recoveries of aminopyrine and sulpyrin in pharmaceutical preparations were 93∼103%.
