title: High-sensitivity detection of 4-(3-pyridinylmethylaminocarboxypropyl) phenylthiohydantoins by capillary liquid chromatography-microelectrospray ion trap mass spectrometry.
abstract: We describe the separation and detection at the low-femtomole level of 4-(3-pyridinylmethylaminocarboxypropyl) phenylthiohydantoins (311-PTHs) by capillary liquid chromatography-microelectrospray ion trap mass spectrometry. Highest sensitivity was obtained in the multiple-ion monitoring operating mode in which we detected 311-PTHs at the 5-fmol level with a signal-to-noise ratio of approximately 10. We investigated the fragmentation patterns of the isobaric 311-PTH isoleucine and 311-PTH leucine by electrospray ionization ion trap tandem mass spectrometry. The compounds could be differentiated by a fragment ion of mass m/z = 366.1 which was specific for the breakdown of 311-PTH leucine, thus allowing for the unambiguous identification of the 311-PTH derivatives of all 20 naturally occurring amino acids by their masses and fragmentation patterns.
authors.affiliation: Department of Molecular Biotechnology, University of Washington, Seattle 98195, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ducret
authors.forename: E J
authors.initials: EJ
authors.lastname: Bures
authors.forename: R
authors.initials: R
authors.lastname: Aebersold
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D010669:Phenylthiohydantoin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000302:isolation & purification; D012680:Sensitivity and Specificity
chemical_list: D000596:Amino Acids; D010669:Phenylthiohydantoin