Highly sensitive electrochemical luminescence determination of thiamine

A highly sensitive electrochemical luminescence (ECL) method has been developed for the determination of thiamine based on electrochemically oxidizing thiamine with rhodamine B as a sensitizer. A weak ECL signal of thiamine was electrochemically generated on a platinum electrode in an alkaline solution and strongly enhanced in the presence of rhodamine B. Under the condition of 0.10 mM rhodamine B, 6 mM CTMAB and 0.36 M sodium hydroxide, the response to the concentration of thiamine is linear range from 0.1 mu g ml(-1) to 2 mu g ml(-1) and a detection limit of 0.08 mu g ml(-1) can be achieved. This method has been successfully applied to the determination of thiamine in pharmaceutical preparations. The energy transfer ECL scheme is also postulated. (C) 1999 Elsevier Science B.V. All rights reserved.