title: Liquid chromatography with amperometric detection using functionalized multi-wall carbon nanotube modified electrode for the determination of monoamine neurotransmitters and their metabolites.
abstract: The fabrication and application of a novel electrochemical detection (ED) method with the functionalized multi-wall carbon nanotubes (MWNTs) chemically modified electrode (CME) for liquid chromatography (LC) were described. The electrochemical behaviors of dopamine (DA) and other monoamine neurotransmitters at the CME were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results indicated that the CME exhibited efficient electrocatalytic effects on the current responses of monoamine neurotransmitters and their metabolites with high sensitivity, high stability and long-life activity. In LC-ED, DA, norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) had good and stable current responses at the CME. The linear ranges of seven analytes were over four orders of magnitude and the detection limits were 2.5 x 10(-10) mol/l for DA, 2.5 x 10(-10) mol/l for NE, 5.0 x 10(-10) mol/l for MHPG, 3.0 x 10(-10) mol/l for DOPAC, 3.5 x 10(-10) mol/l for 5-HT, 6.0 x 10(-10) mol/l for 5-HIAA, 1.25 x 10(-9) mol/l for HVA. The application of this method coupled with microdialysis sampling for the determination of monoamine neurotransmitters and their metabolites in Parkinsonian patients' cerebrospinal fluid was satisfactory.
authors.affiliation: Department of Chemistry, East China Normal University, ZhingShan Road North 3663, Shanghai 200062, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xie
authors.forename: Shiyun
authors.initials: S
authors.lastname: Ai
authors.forename: Fangli
authors.initials: F
authors.lastname: Wan
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Litong
authors.initials: L
authors.lastname: Jin
authors.forename: Jiye
authors.initials: J
authors.lastname: Jin
mesh_terms: D015306:Biogenic Monoamines / Q000378:metabolism*; D016022:Case-Control Studies; D002853:Chromatography, Liquid / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017551:Microdialysis; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010084:Oxidation-Reduction; D010300:Parkinson Disease / Q000134:cerebrospinal fluid; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015306:Biogenic Monoamines; D018377:Neurotransmitter Agents