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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Food Composition and Methods Development Laboratory » Research » Publications at this Location » Publication #209321
Title: Simultaneous Determination of Selected B Vitamins in the NIST SRM 3280 Multivitamin/Multielement Tablets by Liquid Chromatography Isotope Dilution Mass Spectrometry

Author
item Chen, Pei
item Wolf, Wayne

Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2007
Publication Date: 7/1/2007
Citation: Chen, P., Ozcan, M., Wolf, W.R. 2007. Simultaneous determination of selected B vitamins in the NIST SRM 3280 multivitamin/multielement tablets by liquid chromatography isotope dilution mass spectrometry. Analytical and Bioanalytical Chemistry. Available: doi:10.1007/s00216-007-1430-9.

Interpretive Summary: 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. A C18 RP, gradient profile liquid chromatographic (LC) IDMS method for determination of multiple water soluble vitamins in dietary supplement tablets has been developed. As part of a collaborative characterization of the NIST Standard Reference Material 3280: Multivitamin/Multimineral Tablets, isotope-labeled (13C and/or 2H) B-vitamins (B1-thiamine, B6-pyridoxine, nicotinamide, and pantothenic acid) were obtained from commercial sources, with support of the Office of Dietary Supplements (NIH). Stock solutions of the isotope-labeled vitamins were calibrated against USP standard solutions. The SRM tablets, with added amounts of the four isotope-labeled B-vitamins, were extracted and analyzed, by a triple-quad mass spectrometer (MS) with MS/MS detection, in a single LC run. Unknown vitamin concentrations were calculated by comparing the ratio of the integrated LC peak at the different masses of the unlabeled and labeled vitamins. This information will be used to assign values to the NIST SRM 3280, which will be used by public and private sector analysis laboratories in regulatory response for dietary supplement labeling and for contract analysis to populate the USDA/NIH Dietary Supplements Ingredient Database.

Technical Abstract: 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. A liquid chromatographic (LC) IDMS method for determination of multiple water soluble vitamins in dietary supplement tablets has been developed. As part of a collaborative characterization of the NIST Standard Reference Material 3280: Multivitamin/Multimineral Tablets, isotope-labeled (13C and/or 2H) B-vitamins (B1-thiamine, B6-pyridoxine, nicotinamide, and pantothenic acid) were obtained from commercial sources, with support of the Office of Dietary Supplements (NIH). Our LC/IDMS method (developed in part to help assign values to SRM 3280) uses a C18 reverse phase column, an Agilent 1100 HPLC system, and a Quattro Micro triple-quad mass spectrometer (MS). B-vitamin determination was achieved using a gradient LC profile combined with MS/MS detection in Multiple Reaction Monitoring mode. Stock solutions of the isotope-labeled vitamins were calibrated against USP standard solutions. The SRM tablets, with added amounts of the four isotope-labeled B-vitamins, were extracted and analyzed in a single LC run. Unknown vitamin concentrations were calculated by comparing the ratio of the integrated LC peak at the different masses of the unlabeled and labeled vitamins.