LIQUID CHROMATOGRAPHIC & STABLE ISOTOPE DILUTION MASS SPECTROMETRIC METHODS FOR THE DETERMINATION OF WATER-SOLUBLE & LIPID ... SUPPLEMENTS
Location: Food Composition and Methods Development Lab
Title: Simultaneous Determination of Selected B Vitamins in the NIST SRM 3280 Multivitamin/Multielement Tablets by HPLC Isotope Dilution Mass Spectrometry
Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: March 28, 2007
Publication Date: March 28, 2007
Citation: Chen, P., Ozcan, M., Wolf, W.R. 2007. Simultaneous Determination of Selected B Vitamins in the NIST SRM 3280 Multivitamin/Multielement Tablets by HPLC Isotope Dilution Mass Spectrometry. BARC Poster Day, May, 2007, Beltsville, Maryland.
Vitamins are essential non-caloric substances needed in small amounts from the diet to promote growth, health, and life. Vitamins are categorized as fat soluble (A, D, E, and K) and water soluble (C-ascorbic acid and the B vitamins: thiamin, riboflavin, niacin, pyridoxine, folic acid, cobalamin, pantothenic acid, and biotin). The B-vitamins help convert the calories in carbohydrates, proteins, and fat into usable energy for the body and some are essential in the synthesis of red blood cells.
There is increased interest in accurately assessing the total dietary intake of vitamins from all sources, including foods and dietary supplements. Isotope dilution mass spectrometry (IDMS) can be a definitive analytical method for very accurate concentration determinations. IDMS is a technique based on the addition to an analytical sample of a known amount of an isotopically labeled analog of the analyte as an internal standard. The ratio of the amount of added isotopic analog and the naturally occurring compound are measured using mass spectrometry.
In this study, a liquid chromatographic method with IDMS was used for the determination of selected B vitamins in Standard Reference Material (SRM) 3,280 dietary supplement. Vitamin B determinations were achieved using a gradient liquid chromatography (LC) profile combined with detection in multiple reaction monitoring mode. Stock solutions of the isotope-labeled vitamins were calibrated against United States Pharmacopoeia standard solutions. The SRM tablets, with added amounts of the four isotope-labeled B-vitamins (B1, B3, B5, and B6) were analyzed in a single LC run. Unknown vitamin concentrations were calculated by comparing the ratios of the integrated peaks of the unlabeled and labeled vitamins.