Fontaine J, Eudaimon M, Fontaine J, Eudaimon M
Degussa-Hüls AG, Feed Additives Division, Applied Technology, Hanau, Germany.
J AOAC Int. 2000 Jul-Aug;83(4):771-83.
A total of 17 laboratories (including one author's laboratory) participated in a collaborative study for determination of lysine, methionine, and threonine in trade products or concentrated amino acid premixes. Thirteen samples, 4 pure amino acids and 6 premixes, including 3 Youden matched pairs, were analyzed. The applied liquid chromatographic (LC) method using cation-exchange resin and post-column derivatization with ninhydrin or o-phthaldialdehyde was shown to be accurate and specific for the analytes. Titration procedures, normally used for the assay of pure amino acids, are unspecific and the accuracy of the results can be affected by impurities. Repeatability relative standard deviations, RSDr, ranged from 0.84 to 1.17% for pure amino acids and from 0.50 to 1.68% for premixes; reproducibility relative standard deviations RSDR, ranged from 1.52 to 2.31% for pure amino acids and from 1.48 to 2.59% for premixes. Recoveries were between 97.5 and 102.8% of the expected amino acid assays. The method has been adopted Official First Action status by AOAC INTERNATIONAL.
共有17个实验室（包括一位作者所在的实验室）参与了一项合作研究，以测定贸易产品或浓缩氨基酸预混料中的赖氨酸、蛋氨酸和苏氨酸。分析了13个样品，包括4种纯氨基酸和6种预混料，其中有3对尤登匹配对。所采用的使用阳离子交换树脂并通过茚三酮或邻苯二甲醛进行柱后衍生化的液相色谱（LC）方法，对分析物而言准确且具有特异性。通常用于纯氨基酸测定的滴定程序不具有特异性，结果的准确性可能会受到杂质的影响。纯氨基酸的重复性相对标准偏差（RSDr）范围为0.84%至1.17%，预混料的重复性相对标准偏差范围为0.50%至1.68%；纯氨基酸的再现性相对标准偏差（RSDR）范围为1.52%至2.31%，预混料的再现性相对标准偏差范围为1.48%至2.59%。回收率在预期氨基酸测定值的97.5%至102.8%之间。该方法已被美国官方分析化学家协会（AOAC INTERNATIONAL）采纳为官方首次行动标准方法。
