title: Simultaneous determination of urinary creatinine and UV-absorbing amino acids using a novel low-capacity cation-exchange chromatography for the screening of inborn errors of metabolism.
abstract: A simple and versatile low-capacity cation-exchange chromatography system for the simultaneous determination of creatinine and UV-absorbing amino acids was developed. The separation column was packed with a newly developed low-capacity sulfoacylated macro-porous polystyrene-divinylbenzene resin selective for amino-acid cations. Urinary creatinine, creatine, tyrosine, histidine, phenylalanine, and tryptophan were simultaneously separated and determined by an isocratic elution with phosphate/acetonitrile eluent in 25 min. Relative standard deviations (R.S.D.) of the retention times for the analytes were between 0.28 and 1.06%. R.S.D. of peak area responses for the analytes were between 0.75 and 3.51%. The r(2) values for the calibration lines were between 0.9994 and 0.9999. The method could provide the creatinine ratios for the analytes, and was applicable to the screening and/or chemical diagnosis of several inherited disorders of amino-acid metabolism such as phenylketonuria (PKU).
authors.affiliation: Department of Analytical Chemistry, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan. yokyuk@ynu.ac.jp
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamasaki
authors.forename: Hisakuni
authors.initials: H
authors.lastname: Sato
mesh_terms: D000596:Amino Acids / Q000652:urine*; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D003404:Creatinine / Q000652:urine*; D006801:Humans; D007231:Infant, Newborn; D008403:Mass Screening; D008661:Metabolism, Inborn Errors / Q000175:diagnosis*; D009800:Oculocerebrorenal Syndrome / Q000652:urine; D010661:Phenylketonurias / Q000652:urine; D020176:Tyrosinemias / Q000652:urine
chemical_list: D000596:Amino Acids; D003404:Creatinine