Flow-Injection Fluorimetric Determination of Thiamine in Pharmaceutical Preparations

 A new fluorimetric procedure for the determination of thiamine using flow injection analysis is proposed. The method is based on the derivatization reaction of the primary amine group with o-phthalaldehyde in the presence of 2-mercaptoethanol using fluorimetric detection. The calibration graph based on peak area was linear in the range 0.2–6 ng mL⁻¹. The detection limit was close to 0.1 ng mL⁻¹. The method was applied to the determination of the vitamin in commercial pharmaceutical preparations. Received March 31, 1999. Revision October 15, 1999.