Colorimetric Determination of Some N-1-Substituted Nitroimidazoles

A colorimetric method is presented for the determination of some N-1-substituted nitroimidazoles. The method utilizes diazotization of a sulfanilamide with the nitrite ions produced during the alkaline hydrolysis of the respective imidazole. Subsequent coupling is then carried out with Bratton-Marshall reagent. The sensitivity of this method of analysis is approximately 0.1 mcg./ml. This procedure can be used for the determination of one of the N-1-substituted nitroimidazoles, 1-methyl-2-isopropyl-5-nitroimidazole, in feed premixes containing multiple vitamins, and is herein presented.