BS EN ISO 13904:2016规定了总色氨酸和游离色氨酸（Trp）的测定方法 饲料中的含量（如完整和补充饲料、补充饲料、原材料、， 成分和浓缩物）和商业纯物质中游离色氨酸的测定 以及含有2%以上色氨酸的预混料。它不区分D型和L型。交叉引用:2000/45/e购买本文件时，所有当前可用的修订内容均包含在购买本文件中。

BS EN ISO 13904:2016 specifies a method for determination of the total and free tryptophan (Trp) content in feeding stuffs (e.g. complete and complementary feeds, supplementary feeds, raw materials, ingredients, and concentrates) and determination of free tryptophan in commercial pure substances and premixtures containing more than 2 % of tryptophan.It does not distinguish between D- and L-forms.Cross References:2000/45/ECAll current amendments available at time of purchase are included with the purchase of this document.