title: Separation of intermediates of iron-catalyzed dopamine oxidation reactions using reversed-phase ion-pairing chromatography coupled in tandem with UV-visible and ESI-MS detections.
abstract: Reversed-phase ion-pairing chromatography (RP-IPC) is coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) through an interface comprising a four-way switch valve and an anion exchange column. Regeneration of the anion exchange column can be accomplished on-line by switching the four-way switch valve to interconnect the column to a regeneration solution. Positioning the anion exchange column between the RP-IPC and ESI-MS instruments allows the ion-pairing reagent (IPR) sodium octane sulfonate to be removed. The IPC-ESI-MS method enabled us to separate and detect four intermediates of the Fe(III)-catalyzed dopamine oxidation. In particular, 6-hydroxydopamine, which is short-lived and highly neurotoxic, was detected and quantified. Together with the separation of other intermediates, gaining insight into the mechanism and kinetics of the Fe(III)-catalyzed dopamine oxidation becomes possible.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Gargey
authors.initials: G
authors.lastname: Yagnik
authors.forename: Dianlu
authors.initials: D
authors.lastname: Jiang
authors.forename: Shuyun
authors.initials: S
authors.lastname: Shi
authors.forename: Peter
authors.initials: P
authors.lastname: Chang
authors.forename: Feimeng
authors.initials: F
authors.lastname: Zhou
mesh_terms: D002852:Chromatography, Ion Exchange / Q000379:methods; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D016627:Oxidopamine / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016627:Oxidopamine; D007501:Iron; D004298:Dopamine