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Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/6/2006 Publication Date: 3/1/2006 Citation: Chen, P., Wolf, W.R. 2006. Development and Validation of a High-Throughput Based on Liquid Chromatography with UV/MS Detection Method for Quantitation of Cichoric Acid in Echinacea purpurea Aerial-Based Dietary Supplements. Journal of Association of Official Analytical Chemists International. 89:(3)612-618. Interpretive Summary: While current “official” microbiological assay methods for water soluble vitamins are highly sensitive, they are also imprecise due to very detailed laborious procedures that are time-consuming and require multiple determinations to achieve required precision. These microbiological procedures were developed over 50 years ago and are generally outdated in light of new technology. While there are reports in the literature of LC methods for the determination of B vitamins in foods, these methods have not been rigorously validated for general use in response to food labeling regulatory requirements. They are usually not intended for analysis of multi-vitamins in multi-vitamin daily supplements. Today there is increased interest in accurately assessing the total dietary intake of vitamins from all sources, including foods and dietary supplements. A dietary supplement ingredient database comprising analytical values is under joint development by ARS and ODS/NIH. A method using LC/UV in combination with LC/MS/MS for quantification of seven B-complex vitamins (B1 - thiamine, B6 - pyridoxine, B3 - nicotinamide, pantothenic acid, B9 - folic acid, B2 - riboflavin, and biotin) in multi-vitamin daily supplements has been described. This method will be applied initially to determine these vitamins in the NIST multi-vitamin SRM 3680, being jointly developed with NIST and ODS/NIH. Technical Abstract: A method using LC/UV in combination with LC/MS/MS for quantification of seven B-complex vitamins (B1 - thiamine, B6 - pyridoxine, B3 - nicotinamide, pantothenic acid, B9 - folic acid, B2 - riboflavin, and biotin) in multi-vitamin daily supplements has been described. It involves the use of a Phenomenex Hydro-RP C18 column (4 µm, 250 mm × 2.0 mm id) and a gradient mobile phase profile. Gradient elution was performed where phase A is 0.1% formic acid in water and phase B is 0.1% formic acid in acetonitrile, at a flow rate of 0.25 ml/min. After a 5-min isocratic elution at a 100 % A, linear gradient to 50/50 A/B at 15 min and to 5/95 A/B at 17 min. Then the composition was changed back to 100% A at 17.1 min for column equilibrating isocratically for 8 min. Detection was performed with a photodiode array detector (DAD) at 260, 280, and 292 nm as well as a triple-quad mass spectrometer at Multiple Reaction Monitoring (MRM) mode. This method was initially applied to determine these vitamins in the NIST multi-vitamin SRM, being jointly developed with NIST and ODS/NIH. 10 mM phosphate buffer (pH 2.5) extracts of the NIST SRM were analyzed by the LC/UV and LC/MS/MS method. The method does not require any sample clean-up/pre-concentration steps except centrifugation and filtration. |
