title: Measurement of water-soluble B vitamins in infant formula by liquid chromatography/tandem mass spectrometry.
abstract: A method has been developed for the simultaneous measurement of multiple B vitamins (i.e., B1, B2, B3, B5, and B6) in infant formulas by LC-MSIMS. The vitamins were extracted with acidic solvent, followed by protein precipitation at a pH range of 4.5 to 5.5, and filtered. This simplified procedure eliminates many of the potential sources of laboratory error and facilitates rapid and efficient analysis. As is common in most cases, isotope internal standards were added to account for variations in sample preparation, as well as changes in MS measurement. In this method, isotope-labeled internal standards of B1, B3, B5, and B6 were used. The factors affecting analytical performance were investigated and optimized. In addition, the stability of these vitamins in the extraction solution was investigated. An acidic condition (5 mM HCl) was applied to successfully stabilize B1, which had shown a decrease in signal when other solvents were used. The quantitative extraction and good stability allowed isotope standards to be added to the filtered sample solution, instead of to the extraction solvent. The addition of the isotope to the small portion of the filtered sample solution significantly reduces cost. A comprehensive evaluation of the analysis of the standard reference material and good spike recovery of the vitamins (100 +/- 6%) demonstrates the accuracy of the method. The results for commercially available infant formula samples were also compared with those obtained using the current microbiological method.
authors.affiliation: Covance Laboratories Inc., 3301 Kinsman Blvd, Madison, WI 53704, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Huang
authors.forename: Doug
authors.initials: D
authors.lastname: Winters
authors.forename: Richard
authors.initials: R
authors.lastname: Crowley
authors.forename: Darryl
authors.initials: D
authors.lastname: Sullivan
mesh_terms: D002648:Child; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007225:Infant Food / Q000032:analysis*; D012015:Reference Standards; D012995:Solubility; D053719:Tandem Mass Spectrometry; D014803:Vitamin B Complex / Q000032:analysis* / Q000737:chemistry; D014815:Vitamins / Q000032:analysis* / Q000737:chemistry
chemical_list: D007202:Indicators and Reagents; D014815:Vitamins; D014803:Vitamin B Complex