Spectrophotometric Determination of Vitamin B1 (Thia min Hydrochloride)In Pharmaceutical Preparation by Coupling Reaction with Diazotized Sulfanilic acid.

Abstract

A simple, accurate and sensitive spectrophotometric method for the determination of vitamin B1 (hiamin hydrochloride) in aqueous solution is described. The method is based on the diazotization of sulfanilic acid followed by coupling with thiamin hydrochloride in the presence of sodium hydroxide to form reddish-brown water soluble dye that is stable and has maximum absorption at ( )",u*: 490nm ).The molar
absorptivity and sandell sensitivity were 7.74 x103 L.mol-l.cm-r and 0.045pg.cm-l respectively. The procedure is developed for bulk thiamin hydrochloride and some of their pharmaceutical preparalions. The are accurate, precise and comparable to the standard method (British pharmacopoeia).