VOLUMETRIC DETERMINATION OF NITROGEN CONTENTS IN CERTAIN ORGANIC MEDICAMENTS

Volumetric Determination of nitrogen content in 14 drugs,most of which are official in Chinese Pharmacopoeia 1953,by means of modified Kjieldahl method without distillation were described.Ammonium sulfate formed during Kjieldahl digestion combined itself with formaldehyde after the solution was neutralized carefully. The free acid liberated according to the following reaction was then titrated. 4NH₄⁺+6HCHO(CH₂)₆N₄+4H⁺+6H₂O It was found that Antipyrin,pyramidon,sodium barbital and pentobarbital sodium were giving low results.Volatile nitrogenous compounds evolved in the process of Kjieldahl digestion were subjected to combustion at a relatively low temperature,about 400℃,through a combined Kjieldahl-Dumas apparatus,wherein they were further degraded to nitrogen.The total amount of nitrogen thus obtained showed close agreement with the theoretical value.