2017.03 Amino Acids (Tryptophan) - Amino-02

2017.03 (JULY 2018) Amino-02 TRP_AOAC_2017.03_MLT_Corrected 080218

FOR ERP USE ONLY DO NOT DISTRIBUTE

Study Information

Study Title: Collaborative Study of AOAC First Action 2017.03 for the HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis.

Study Objective: The objective of this study is to complete validation of AOAC First Action 2017.03 for the quantification of tryptophan in infant, pediatric, and adult nutritionals by determining method reproducibility and repeatability. Study Director

Jonathan Draher Abbott Nutrition 3300 Stelzer Road Columbus, OH 43219 P: 614 624-4231 jonathan.draher@abbott.com

Study Monitors: AOAC International (SPIFAN) Official Method Board or delegated personnel.

MLT Overview

Participating laboratories were asked to set up the method (Appendix A), analyze two practice samples in duplicate, and report the results to the study directors. After successful analysis of the practice samples, study participants were asked to analyze 14 SPIFAN matrices in duplicate. The samples were split into groups of 14 and 14 per the data reporting templates, and each group was analyzed on a separate day. Participants were asked to reconstitute all powder samples by diluting either 10 or 25 grams of powder to 100 or 225 grams respectively with water. Electronic excel templates for reporting sample weights and results were provided. After completion of the study, the data were analyzed using the AOAC International Interlaboratory Study Workbook for Blind (unpaired) Replicates, Version 2.1 to calculate repeatability standard deviation, s(r), reproducibility standard deviation, s(R), repeatability relative standard deviation, RSD(r), reproducibility relative standard deviation, RSD(R), and HORRAT value to detect outliers.

Table 1: MLT Sample Matrices with Codes