AOAC OMA# 2011.14 (Final Action Review)-OMB

2011.14 (Oct. 2018) – MTE-03 Final Action Review FOR ERP USE ONLY DO NOT DISTRIBUTE

butter, processed cheese, whey powder, whole UHT milk, whole milk powder, and whey protein concentrate powder) provided by MUVA (Kempten, Germany) for a total of 24 product samples and 1 SRM. The placebo products are not fortified with Cu, Fe, Mg, or Zn. The SPIFAN kit included powders, ready-to-feed (RTF) liquids, and liquid concentrates. Suppliers ensured homogeneity of the matrixes by testing 10 subsamples for several analytes with pre-determined acceptance criteria. Samples were shipped to the collaborators as blind duplicates, so each collaborator received 38 SPIFAN II materials and 12 IDF materials.

Study Design.- Study materials were pre-assigned for analysis on either Day 1 or Day 2 by qualified collaborators, with blind duplicates analyzed on the same day. The SRM was analyzed on both days as a control.

Statistical Analyses.- Statistical analyses followed the AOAC Official Methods of Analysis Appendix D guidelines (7). Data were examined for outliers using the Cochran (p=0.025, 1 tail) and Grubbs (single and double, p=0.025, 2-tail) tests. After removal of outliers, the blind duplicates within each laboratory were analyzed for mean, standard deviation of repeatability (s r ), and relative standard deviation of repeatability (RSD r ). Data among laboratories were analyzed for mean, standard deviation of reproducibility (s R ), and relative standard deviation of reproducibility (RSD R ). The AOAC Interlaboratory Study Workbook for Blind (Unpaired) Replicates (2013) Version 2.1 was used (8).