AOAC SPIFAN Nutrients ERP-Final Review (Jan. 2019)

2015.10 (Jan. 2019) Carn-07 MLT Report FOR ERP USE ONLY DO NOT DISTRIBUTE

Study Design This study was conducted on ten test materials in blind duplicates, one of which was NIST SRM 1849a Infant/Adult Nutritional Formula. Random identification numbers were assigned to each of the sample test materials. Each sample was analyzed two times by the participating labs, once each using the free or total extraction method. Test Sample Preparation and Shipment Test samples, used in this study, were obtained from commercial sources and provided by AOAC INTERNATIONAL and the International Formula Council (IFC). Individually prepared test kits including all ten blind duplicate samples were provided to each collaborator. See Appendix 1 for a list of samples. All powdered samples were directed to be analyzed on a reconstituted basis where approximately 25 grams of material was diluted with approximately 200 grams of de-ionized water per the provided method and protocol. Some laboratories did not follow the directed procedure from the protocol and SMPR and instead weighed 10grams of material into 90 grams of water. Once the test material was in solution and well mixed, an aliquot of approximately 0.5-1 grams was sub-sampled for analysis. This reconstituted solution was discarded after 24 hours. For ready to feed (RTF) samples the laboratory weighed approximately 0.5-1 grams for analysis. Samples were shipped at ambient temperature. Laboratories were asked to store the samples at room temperature before and during analysis with the exception of the RTF samples which were refrigerated after the initial sampling and discarded within five days of opening. Bulk standards were to be stored as directed on the certificate of analysis/receipt paperwork. Laboratories were directed to follow instructions in the method for storage and shelf-life of solutions. Standards The following reference standards were purchased by each collaborator and weighed for use in the study: Reference standards • L-Carnitine (USP, Rockville, MD) or equivalent. • Choline Bitartrate (TCI, Tokyo, Japan) or equivalent. A mixed internal standard solution at the working solution concentration (200 µg/mL) was provided to each collaborator for use in the study. Internal standard • L-Carnitine-d3 HCl (CDN Isotopes, Pointe Claire, Québec, Canada). • Choline-1,1,2,2-d4 Chloride (CDN Isotopes).

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