IDF 254 | ISO 4214: 2022 - Milk and milk products - Determination of amino acids in infant and adult / paediatric nutritional formulas and dairy products

This document specifies a method for the quantitative determination of total amino acids using 6-aminoquinolyl-N-hydroxy-succinimidyl carbamate (ACQ) derivatization followed by ultra-high-performance liquid chromatography (UHPLC) separation and ultraviolet (UV) detection. It specifies a method for the determination, in one single analysis, of the following amino acids: alanine, arginine, aspartic acid (combined with asparagine), cystine (dimer of cysteine, combined with cysteine), glutamic acid (combined with glutamine), glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine and valine.

This method does not apply to the determination of tryptophan.

This method is applicable to infant and adult/paediatric nutritional formulas, dairy products and other matrices such as cereals. It was validated in infant formulas (milk- and soy-based, including partially hydrolysed and elemental products), toddler formula, adult nutritional powder, UHT skimmed milk, whey powder, sodium caseinate, whole milk powder, bran pet food, dry pet food and breakfast cereal.