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Biomedical subjects

Yunfeng Xie

Publications and source records attributed to Yunfeng Xie.

3 recordsLinked to original sources

Liquid chromatography with amperometric detection at a nano crystalline Ce-doped lead dioxide film modified electrode for determination of (R)-Salsolinol, (R)-N-methylsalsolinol and monoamine neurotransmitters in Parkinsonian patients' cerebrospinal fluid.

The fabrication and application of a novel electrochemical detector (ED) with nano crystalline Ce-doped lead dioxide film chemically modified electrode (CME) for liquid chromatography (LC) were described. The Ce-doped PbO(2) film was characterized by X-ray diffractometer (XRD) and scanning tunnel microscope (STM). The electrochemical behaviors of (R)-Salsolinol ((R)-Sal) at the CME were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the CME exhibited an efficiently electrocatalytic effect on the current responses of (R)-Sal, (R)-N-methylsalsolinol ((R)-NMSal) and monoamine neurotransmitters. In LC-ED, all (R)-Sal, (R)-NMSal, dopamine (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 the nine analytes were over three orders of magnitude (R(2) > 0.995). The application of this method coupled with microdialysis sampling for the determination of (R)-Sal, (R)-NMSal and monoamine neurotransmitters in Parkinsonian patients' cerebrospinal fluid (CSF) was satisfactory.

Chromatography, Liquid↗

Liquid chromatography with amperometric detection using functionalized multi-wall carbon nanotube modified electrode for the determination of monoamine neurotransmitters and their metabolites.

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.

Biogenic Monoamines↗

Simultaneous determination of the monoamine neurotransmitters and glucose in rat brain by microdialysis sampling coupled with liquid chromatography-dual electrochemical detector.

A new type of chemically modified electrode based ring-disk electrode as the dual electrochemical detector (DECD) for high-performance liquid chromatography (HPLC) to simultaneously determine the monoamine neurotransmitters and glucose is described. The ring electrode was modified with an ion-exchange polymer-overoxidized polypyrrole (OPPy) and the disk electrode was modified with nano Au colloid and glucose oxidase (GOD). The electrochemical behaviors of dopamine (DA) and ascorbic acid (AA) at the OPPy chemically modified electrode (CME) were investigated by differential pulse voltammetry (DPV). It was found that the CME could permeate dopamine cations and repelled the ascorbate anions, which could be used to determine the monoamine neurotransmitters and avoid the interference of AA. The electrochemical behavior of glucose at the Nafion/GOD-Au colloid/GC CME was investigated by amperometry and flow injection analysis (FIA). It was found that the sensitivity of the CME increased apparently in determination of glucose. In order to obtain better separation and current responses of the analytes in HPLC-DECD, several operational parameters have been investigated. Under the optimum conditions, the method showed good stability and reproducibility. The application of this method coupled with microdialysis sampling for in vivo simultaneous determination of monoamine neurotransmitters and glucose in rat brain was satisfactory.

Animals↗