Amino acid analysis is fundamental to determine amino acid composition of proteins, peptides and biological and/or pharmaceutical samples. Many congenital metabolic disorders produce an abnormal accumulation of some amino acids, compromising human health. Here, 24 amino acids are determined and quantified in plasma or urine that allows professionals to diagnose the corresponding amino acid disease as well as to use the technique for its nutritional monitoring. In addition to this important application, the determination of amino acids in consumer products, such as protein supplements, medicines, among others, makes it possible to evaluate their true nutritional value and bioavailability, since several amino acids are essential in the human and animal diet and also there are pathologies associated with the consumption of some amino acids.