title: High-performance liquid chromatography method for the simultaneous determination of thiamine hydrochloride, pyridoxine hydrochloride and cyanocobalamin in pharmaceutical formulations using coulometric electrochemical and ultraviolet detection.
abstract: The method for the simultaneous determination of thiamine hydrochloride, pyridoxine hydrochloride and cyanocobalamin by high-performance liquid chromatography (HPLC) with coulometric electrochemical and UV detections is presented. The retention time of vitamins was repeatedly determined by isocratic elution using 0.05 M phosphate buffer-10% methanol and 0.018 M trimethylamine (1 ml min(-1), pH 3.55) as mobile phase with the Supelco LC 18 column 5 microm (25 cm x 4.6 mm). The specificity of the method was demonstrated by the retention characteristics, coulometric electrochemical and UV detection. The limits of detection of thiamine, pyridoxine and cyanocobalamin were: 9.2, 2.7 and 0.08 ng/ml, respectively. The method was characterized also by wide concentration range, high sensitivity and good accuracy (99.6-102.7%). The repeatability of the method was evaluated at different level of concentration of vitamins and the relative standard deviation was below 4.5%. The method was successfully applied for the quantification of Vitamins B1, B6 and B12 in pharmaceutical preparations and dietary supplements.
authors.affiliation: Department of Toxicology, Medical University of Gdańsk, Al. Gen. J. Hallera 107, Gdańsk 80-416, Poland.
authors.forename: Marcin Leszek
authors.initials: ML
authors.lastname: Marszałł
authors.forename: Anna
authors.initials: A
authors.lastname: Lebiedzińska
authors.forename: Wojciech
authors.initials: W
authors.lastname: Czarnowski
authors.forename: Piotr
authors.initials: P
authors.lastname: Szefer
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011736:Pyridoxine / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013831:Thiamine / Q000032:analysis*; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D011736:Pyridoxine; D014805:Vitamin B 12; D013831:Thiamine