title: A simple liquid chromatographic method based on intramolecular excimer-forming derivatization and fluorescence detection for the determination of tyrosine and tyramine in urine.
abstract: A liquid chromatographic (LC) method for sensitive and selective fluorometric determination of p-hydroxyphenylethylamino group containing compounds is described. This method is based on an intramolecular excimer-forming fluorescence derivatization with a pyrene reagent, 4-(1-pyrene)butanoyl chloride, followed by reversed-phase LC. The analytes, containing an amino moiety and a phenolic hydroxyl moiety in a molecule, were converted to the corresponding dipyrene-labeled derivatives by one-step derivatization. The dipyrene-labeled derivatives afforded intramolecular excimer fluorescence (440-540 nm), which can clearly be discriminated from the normal fluorescence (360-420 nm) emitted from reagent blanks. The derivatives of tyrosine and tyramine could be separated by reversed-phase LC on ODS column under conditions of isocratic elution. The detection limits (signal-to-noise ratio = 3) for tyrosine and tyramine were 4.5 and 2.6 fmol per 20 microL injection, which corresponded to analyte concentrations of 0.9 and 0.5 nM, respectively.
authors.affiliation: Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Johnan, Fukuoka 814-0180, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nohta
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Harada
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshitake
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Todoroki
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamagata
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D002073:Butanes / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D011721:Pyrenes / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D014439:Tyramine / Q000652:urine*; D014443:Tyrosine / Q000652:urine*
chemical_list: C499821:4-(1-pyrene)butanoyl chloride; D002073:Butanes; D011721:Pyrenes; D014443:Tyrosine; D014439:Tyramine