AOAC RI ERP E-Book - DS DF

OMA 2014.10 C: Collaborative Study Manuscript Expert Review Panel Use Only September, 2017

2013 Dietary Starch in Animal Feeds Collab Study Protocol 072513

Pre-Trial Samples Specimens will be provided to collaborators as part of the pre-trial familiarization process. These will include glucose and corn starch control samples, and 3 ground samples with which to familiarize themselves with the handling characteristics of feed samples. These materials are to be used by the participants to set up, implement the method and demonstrate proficiency with the dietary starch method prior to shipment of the study materials. Raw data of sample weights and absorbance values measured on the spectrophotometer as well as the calculated results will be used to determine the performance of the laboratories. Results of the analysis of the glucose samples will allow determination of detection limits of the laboratories. The pre-trial specimen shipment and analysis will be used to address various hurdles that may arise during the collaborative study. The results from the analysis of the pre-trial samples will be used to determine if the laboratory can meet the suitability requirements of the dietary starch method and will proceed to the Study stage of the process. Study Materials The 20 study materials are provided to the participating laboratories as dry ground or wet homogenized samples. Additional QA specimens will be supplied to the participants, these include: • Control glucose and corn starch samples 5. Proposed approach to data analysis. The data will be analyzed in terms of free glucose and dietary starch. The study utilizes blind duplicates for all materials; the results of the blind duplicate sample analysis will be examined for evidence of individual systematic error. This will be accomplished by the use of Cochran and Grubbs tests progressively using the AOACI Statistical Program 2001 for Blind Replicate Spreadsheets. The method recovery will be determined from analysis of the results of the control corn starch samples analyzed by each laboratory. Calculations for repeatability (s r ) and reproducibility (s R ), as defined by the AOAC guideline reference below, will be carried out after removal of outliers. HORRAT values, the ratio of the reproducibility relative standard deviation to the predicted reproducibility relative standard deviation, will be calculated. Acceptable HORRAT values will be between 0.5 and 2.0. Please refer to: Official Methods of Analysis, 18th Edition (2005), Appendix D: “Guidelines for Collaborative Study Procedures to Validate Characteristics of a Method of Analysis.” 6. Other participating organizations. The collaborative study has been planned and organized by the U. S. Dairy Forage Research Center of USDA-ARS in collaboration with AAFCO. Stakeholders that have reviewed and support this application include Kansas Department of Agriculture, Metrohm USA, Oregon Department of Agriculture, South Dakota State University, Eurofins, Missouri Department of Agriculture, Canadian Feed Inspection Agency, Nestle-Purina Pet Care, OISC/Purdue University, University of Kentucky Regulatory Services, and National Corn-to-Ethanol Research Center. 7. Estimated number of collaborators. 15 Call Letter AOAC Research Institute ERP Use Only

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