Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7608273 | Journal of Chromatography A | 2018 | 31 Pages |
Abstract
A simple cyclodextrin-mediated capillary zone electrophoresis method equipped with a laser-induced fluorescence detector was developed for chiral analysis of the excitatory amino acids aspartate (Asp) and glutamate (Glu). Plasma and cerebrospinal fluid (CSF) samples were pretreated with centrifugal filter devices before analysis to remove high-molecular-weight proteins (molecular weight cut-off: 3000) and then derivatized using 10â¯mM 6-carboxyfluorescein N-hydroxysuccinimide ester in DMSO under sonication at 25â¯Â°C for 2â¯h. After the derivatization reaction, reacted samples were diluted 100-fold with 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein hydrochloride (DTAF) solution and then hydrodynamically subjected to capillary electrophoresis (0.5â¯psi for 5â¯s, injection volume 8.27â¯nL). The separation buffer consisted of 50â¯mM borate buffer (pH 9.0) with 6â¯mM γ-CD and 0.1% polyvinylpyrrolidone, and the separation voltage was set at 20â¯kV. In the linearity calculations for the determination of d/l-Asp and d/l-Glu in plasma and CSF, a standard addition method was utilized to spike solutions with 0-20.0â¯Î¼gâ¯mLâ1l-Glu and 0-2.0â¯Î¼gâ¯mLâ1d-Glu and d/l-Asp to construct calibration curves. Correlation coefficients were above 0.998 for every analyte. The limits of detection (S/Nâ¯=â¯3) for d/l-Asp and d/l-Glu standard solutions were 0.85-0.96â¯Î¼gâ¯mLâ1. The proposed method was applied successfully to determine d/l-Asp and d/l-Glu concentrations in the plasma and CSF samples of 26 patients with Alzheimer's disease (AD), and the association between these concentrations and disease severity was investigated. Statistical analysis showed a moderately negative correlation (râ¯=â¯â0.158) between plasma l-Asp concentration and AD severity.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ya-Hui Hsieh, Fang-Yi Liao, Yuan-Han Yang, Jing-Ru Weng, Su-Hwei Chen, Chia-Hsien Feng,