2009 Annual Report
Objective 2: Develop and validate new or updated analytical methods using current technology to determine the levels of water-soluble vitamins (WSV), lipid soluble vitamins (LSV) and/or other components for foods and dietary supplements. Sub-Objective 2.A: Develop/update and optimize measurement procedures to establish validated capability for simultaneous measurements of multiple WSV (SimWSV). Sub-Objective 2.B: Develop and validate analytical methods for the determination and quantification of LSV (A, D, E, and K) and lipids in food matrices and dietary supplements. Sub-Objective 2.C Develop/update and optimize measurement procedures to establish validated capability for measurements of vitamin B12 in dietary supplements and foods. Sub-Objective 2.D Develop multivariate calibration methods for simultaneous determination of multiple vitamins in extracts with no prior chromatographic separations.
Objective 3: Develop and validate sample preparation procedures to optimize extraction, remove interferences, and/or to concentrate difficult to analyze vitamins in foods and dietary supplements.
Objective 4: Catalyze cooperative activities to identify and provide improved measurement systems and essential Reference Materials for vitamins in foods and dietary supplements. Provide analytical data to characterize the vitamin content of selected Reference Materials. Sub-Objective 4.A: Generate information with developed and validated methods to assign value-added information on vitamin content to available Reference Materials. Sub-Objective 4.B: Catalyze development of overall measurement systems for vitamins in foods and dietary supplements.
Objective 3: Multiple extractions for WSV with different buffers, pHs, and multiple extraction approaches (including classical and modern methods such as pressurized liquid extraction [PLE], microwave-assisted extraction [MAE], ultrasonic irradiation, stirring, shaking, and Soxhlet) will be systematically explored to ensure complete extraction and compare extraction efficiencies of different procedures. The lipid soluble vitamins (LSV) (A, D, E, K) would be similarily extracted with a organic solvents of different polarities.
Objective 4: FCMDL capability for high quality vitamin determinations will be applied to provide reference measurements to value to NIST SRMs such as the Adult/Infant Formula SRM and Fortified Cereal SRM. Through initiating and providing guidance for a number of nutrition metrology-related activities, FCMDL will catalyze improvement of the overall measurement system for vitamins. FCMDL will participate as collaborators in method validation studies as appropriate. FCMDL will continue to organize and advise the development and conduct of symposia, and other appropriate workshops.
The FCMDL liquid chromatography/ultraviolet/fluorometric/mass spectrometry (LC/UV/FL/MS) method for Vitamin B6 has been chosen by an AOAC Expert Review Panel to be included for development as a “World Class” method for vitamin analysis in dietary supplements. A method for vitamin B12, collaboratively developed by FCMDL with the Department of Food Safety and Nutrition, National Institute of Health, Lisbon, Portugal, was also considered by this expert panel. Definitive data from FCMDL was utilized to assign values for water soluble vitamins (WSV) and vitamin D to the new Standard Reference Material 1849 Infant/Adult formula released by NIST in July 2009. Initial results have been generated to compare a variety of extraction techniques for vitamins in dietary supplements and fortified cereals.
Vitamin-fortified cereal samples collected regionally for the USDA National Food and Nutrient Analysis Program (NFNAP) have been analyzed for WSV content. Almost all cereal samples analyzed had vitamin levels significantly higher than label-claim values, in line with general manufacturing practice of over-fortifying to provide adequate shelf life.
The improved vitamin D method which combined the extraction procedure from AOAC 992.26 with the chromatographic system from AOAC 2002.05 previously developed for food analysis was modified recently to allow analysis of vitamin D2 in mushrooms. Vitamin D3 was used as an internal standard for quantification of vitamin D2, and samples were run with and without internal standard to allow the small amount of endogenous vitamin D3 to be determined along with vitamin D2.
Chen, P., Atkinson, R.L., Wolf, W.R. 2009. Single lab validation of a LC/UV/FLD/MS method for simultaneous determination of water-soluble vitamins in multi-vitamin dietary supplements. Journal of the Association of Official Analytical Chemists. 92(2):680-688.