Amino Acids Working Group Meeting Book (July 3, 2018)

Official Methods • AOAC 994.12, Amino Acids in Feeds (1997) – Performic Acid Oxidation/Acid Hydrolysis: Cys(CSSC) determined as cysteic acid, methionine determined as methionine sulfone. Tyr, Trp destroyed. Analysis by ion exchange/ninhydrin. • AOAC 985.28, Sulfur Amino Acids in Foods, Feed Ingredients, and Processed Foods (1986) – Performic Acid Oxidation/Acid Hydrolysis: Cys(CSSC) determined as cysteic acid, methionine determined as methionine sulfone. Only determination of these two are specified. Analysis by ion exchange/ninhydrin. Official Methods • AOAC 988.15 – Tryptophan in Foods and Food and Feed Ingredients (1988, First Action) – Alkaline hydrolysis (4.2 M NaOH). Only Trp determination is specified. Analysis by ion exchange/ninhydrin or RP HPLC/UV. • AOAC 997.05 – Taurine in Powdered Milk and Powdered Milk Formulae (2001) – Dansyl Chloride pre-column derivatization. Analysis using RP HPLC/UV (F).