2009 Annual Report
Over the five years of the project, methods were developed to simultaneously determine water soluble vitamins in dietary supplements and fortified foods using HPLC with multiple diode array ultraviolet and fluorescence detection. A series of samples collected for the USDA NFNAP program consisting of four regional composites of each of 12 separate cereal brand-name products was analyzed for water soluble vitamin content. The new multivitamin method was used to determine vitamins for assigning nutrient values for the new Standard Reference Material 1849 Adult/Infant Formula released in 2009 by the National Institute of Standards and Technology.
A definitive analytical method developed using isotope dilution-liquid chromatography/mass spectrometric (ID-LC/MS) for the analysis of individual water soluble vitamins (thiamin, niacin, pyridoxine, folic acid, biotin, pantothenic acid, and ascorbic acid) in dietary supplements was extended to fortified foods. This required custom synthesis of previously unavailable multiple isotope-labeled vitamins for use as internal standards for these methods. This methodology was used to obtain an alternate confirming set of data used in assigning final values to the new SRM 1849 Adult/Infant Formula released by the NIST in 2009.
In preparation for the project to develop analytical values for vitamin D, an improved method of vitamin D analysis was developed. The best aspects of two methods to analyze vitamin D from the Association of Official Analytical Chemists (AOAC) (Method 2002.05 and Method 992.26) were incorporated into a single method that has been found to be effective for a wide range of food sample matrices. Conditions for the two chromatographic separations in the method and for atmospheric pressure chemical ionization mass spectrometry (APCI-MS) of vitamin D have been optimized.
FCMDL then participated in a round robin collaborative study for the analysis of five representative foods for vitamin D: skim milk, multi-grain cereal, orange juice, Alaskan red sockeye salmon, processed cheese food, and a diluted vitamin D standard from the U.S. Pharmacopoeia. The analytical results from the FCMDL demonstrated the lab’s ability to analyze samples for the National Nutrient Databank; FCMDL has undertaken analysis of additional samples as identified by the NDL and the Food Surveys Research Group.
Byrdwell, W.C., Devries, J., Exler, J., Harnly, J.M., Holden, J.M., Holick, M., Hollis, B., Horst, R., Lada, M., Lemar, L.E., Patterson, K.K., Phillips, K., Tarrago-Trani, M., Wolf, W.R. 2008. Analyzing vitamin D in foods and supplements: Methodological challenges. American Journal of Clinical Nutrition. 88:554S-557S.
Byrdwell, W.C. 2009. Comparison of analysis of vitamin D3 in foods using ultraviolet and mass spectrometric detection. Journal of Agricultural and Food Chemistry. 57(6):2135-2146.