title: Quantification of Five Clinically Important Amino Acids by HPLC-Triple TOF™ 5600 Based on Pre-column Double Derivatization Method.
abstract: Phenylalanine, tyrosine, glycine, cystine, and phosphoethanolamine are commonly measured amino acids in various physiological fluids to diagnose or follow-up various inborn errors of metabolism. The gold standard method for the amino acids quantitation has been ion exchange chromatography with ninhydrin post-column derivatization. However, this method is very laborious and time consuming. In recent years, liquid-chromatography mass spectrometry is being increasingly used for the assay of amino acids. Pre-column butyl derivatization with reverse phase chromatography has been widely used for mass spectrometry analysis of amino acids. Phosphoethanolamine is not butylated and cannot be measured by this method. Nevertheless, phosphoethanolamine can be dansyl-derivatized using dansyl chloride. We developed a double derivatization method by using butanol and dansyl chloride to derivatize carboxylic and amino groups separately, and then combining the derivatives to simultaneously measure these five amino acids using TOF-MS scan. Stable isotope-labeled internal standards were used.
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals and Clinics, 2401 Gillham Road, Kansas City, MO, 64108, USA.
authors.forename: Shuang
authors.initials: S
authors.lastname: Deng
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals and Clinics, 2401 Gillham Road, Kansas City, MO, 64108, USA.
authors.forename: David
authors.initials: D
authors.lastname: Scott
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals and Clinics, 2401 Gillham Road, Kansas City, MO, 64108, USA. ugarg@cmh.edu.|University of Missouri School of Medicine, Kansas City, MO, USA. ugarg@cmh.edu.
authors.forename: Uttam
authors.initials: U
authors.lastname: Garg
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry*; D053000:Analytic Sample Preparation Methods; D000440:Butanols / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003619:Dansyl Compounds / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D000596:Amino Acids; D000440:Butanols; D002264:Carboxylic Acids; D003619:Dansyl Compounds; C029038:dansyl chloride
keywords: Butylation; Cystine; Dansylation; Glycine; HPLC-TOF-MS; Phenylalanine; Phosphoethanolamine; Tyrosine