Determination of thiamine by continuous flow chemiluminescence measurement

The chemiluminescence produced by oxidation of thiamine by ferricyanide in alkaline medium has been investigated by using a simple continuous flow analyser and a procedure developed for the determination of thiamine hydrochloride or nitrate in the range 2.00 x 10(-5)-5.00 x 10(-4)M (equivalent to 6.75-169 mug/ml thiamine hydrochloride) with coefficients of variation <2%. A measurement rate of 112/hr can be obtained. When applied to pharmaceutical formulations, the only interferent among common excipients and coexisting drugs is ascorbic acid. The results obtained for the assay of dosage forms compared well with those obtained by an official method and demonstrated an error <4%.