Trace analysis of AChEIs and active amino acids in patients with Alzheimer's disease by capillary electrophoresis
| Autor: | Ya-Hui Hsieh, 謝雅蕙 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 In this thesis, analytical methods were developed for the trace determination of drugs and amino acids by capillary electrophoresis (CE). The major studies are focused on the determination of acetylcholonesterase inhibitors (AChEIs) in plasma and chiral analysis of excitatory amino acids (EAAs), aspartate and glutamate, in human plasma and CSF. The two studies were applied in the evaluation of AChEIs concentrations and chiral excitatory amino acids concentrations in patients with Alzheimer’s disease, respectively. The summaries were listed as follows： A. Simultaneous determination of galantamine, rivastigmine and NAP 226-90 in plasma by MEKC and its application in Alzheimer’s disease A simple and sensitive MEKC with UV detection was developed for the simultaneous determination of AChEIs, including galantamine, rivastigmine and major metabolite NAP 226-90 in plasma. A sample pretreatment by liquid–liquid extraction with diethylether and subsequent quantification by MEKC was used. The optimum separation for these analytes was achieved in less than 10 min at 25℃ with a fused-silica capillary of 30.2 cm× 50 μm id (effective length 20 cm) and the run buffer was consisting of 25 mM Tris buffer (pH 5.0) with 160 mM sodium octanesulfonate, 20% ACN and 0.01% plyvinylpyrrolidone. In this method, the LODs of galantamine, rivastigmine and NAP 226-90 were 0.25, 0.125 and 0.125 ng/ mL, respectively. Besides, this MEKC method possessed good precision and accuracy. This method was applied in the drug concentration–time profile study of rivastigmine and its metabolite, NAP 226-90, and also applied in monitoring galantamine or rivastigmine and its metabolite NAP 226-90 in 11 Alzheimer’s disease patients’ plasma after oral administration of the commercial products Reminyl® (8 mg galantamine/capsule) or Exelon® (3 mg rivastigmine capsule), respectively. B. Chiral analysis of aspartate and glutamate in biological samples by capillary electrophoresis and application in investigating the relationship between EAAs concentrations and Alzheimer’s disease A simple CD-mediated CZE method equipped with laser-induced fluorescence (LIF) detector was developed in this study for chiral analysis of excitatory amino acids (EAAs), aspartate and glutamate, and to determine the EAAs concentrations in plasma and CSF of patients with Alzheimer’s disease. Before analysis, plasma and CSF samples were pretreated with centrifugal filter devices for removing proteins with high molecular weight (molecular weight cut off 3000) and then derivatized with 10 mM 6-carboxyfluorescein N-hydroxysuccinimide ester/ DMSO. The ratio of filtrate to the derivatizing reagent is 5 (v/v= 5：1). Mixed samples were sonicated for 2 h at 25℃ for chemical derivatization. After the derivatization reaction, reacted samples were diluted 100-fold with water and then hydrodynamically injected into CE instrument (0.5 psi for 5 s). The separation buffer was consisting of borate buffer 50 mM (pH 9.0) with 6 mM γ-CD and 0.1% PVP. The separation voltage was set at 20 kV. This method was applied in determining the EAAs concentrations of 26 patients with Alzheimer’s disease. We compared the EAAs concentrations and CDR-SB or MMSE and then discussed the relationship between EAAs concentrations and Alzheimer’s disease. From the results, there’s a moderately negative correlation between L-Asp concentration in plasma and CDR-SB values. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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