| Home |
An AOAC expert review panel (ERP) granted First Action status to methods for inositol, ultra trace minerals, and nucleotides in infant formula and adult/pediatric nutritional formula. Methods were evaluated against standard method performance requirements (SMPRs) developed by the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), chaired by Darryl Sullivan of Covance Laboratories. Working groups developed SMPRs for each nutrient, which were posted for public comment and approved by SPIFAN. In September 2011, an ERP approved a method for determination of myo-inositol (free and bound as phosphatidylinositol) in infant formula and adult/pediatric nutritional formula. The HPLC method uses amperometric detection and shows good recovery and precision data. Submitted by Abbott, the method has been in use since 1994. The Working Group on Inositol is chaired by Harvey Indyk, Fonterra Cooperative Group Ltd., and Karen Schimpf, Abbott Laboratories. The Working Group on Nucleotides, chaired by Brendon Gill, Fonterra Cooperative Group Ltd., recommended two methods, which were both approved by the ERP. In the method for routine analysis of 5'-mononucleotides in infant formula and adult/pediatric nutritional formula by liquid chromatography, sample is dissolved in a high salt solution to inhibit protein and fat interactions. Nucleotides are then extracted using strong anion exchange solid-phase extraction, then are analyzed by reversed-phase LC using photodiode array detection. Quantitation is by internal standardization against thymidine 5’-monophosphate. In “Development and Application of an HILIC-MS/MS Method for the Quantitation of Nucleotides in Infant Formula and Adult/Pediatric Nutritional Formula,” [J. Agric. Food Chem. 58, 9918-9924(2010)] sample is dissolved in water followed by centrifugal ultrafiltration to remove compounds with a molecular weight higher than 3000. Isotopically labeled internal standards are used from the beginning of sample preparation, and a HILIC column is used for LC separation. Both milk- and soy-based infant formula matrixes were studied. As recommended by the Working Group on Ultra Trace Minerals, chaired by Joseph Thompson, Abbott Nutrition, an ERP adopted a method for simultaneous determination of chromium, selenium, and molybdenum in infant formula and adult/pediatric nutritional formula by ICP-MS. The single-laboratory validation was published in the July/August 2011 issue of the Journal of AOAC INTERNATIONAL [Pacquette, L.H., Szabo, A., & Thompson, J.J. (2011) J. AOAC Int. 94, 1240]. With approval of these methods, an AOAC ERP has adopted a total of 15 First Action Methods for the SPIFAN initiative. Approved methods have been codified and will be drafted into AOAC style for publication in the Journal of AOAC INTERNATIONAL and Official Methods of AnalysisSM. Full coverage is scheduled for the November/December 2011 issue of Inside Laboratory Management. For more information on AOAC’s infant formula initiative and/or SPIFAN, visit http://www.aoac.org/SPIFAN/aoac.htm or contact Anita Mishra, executive for scientific business development, at amishra@aoac.org or Deborah McKenzie, senior director of standards development, at dmckenzie@aoac.org.
|
