Chemically L-phenylalaninamide-modified monolithic silica column prepared by a sol-gel process far enantioseparation of dansyl amino acids by ligand exchange-capillary electrochromatography
Chemically L-phenylalaninamide-modified monolithic silica column prepared by a sol-gel process far enantioseparation of dansyl amino acids by ligand exchange-capillary electrochromatography
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DOI：
10.1021/ac010243p
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发表时间：
2001-07-15
影响因子：
7.4
通讯作者：
Hobo, T
中科院分区：
文献类型：
--
作者：
Chen, ZL;Hobo, T
本文采用溶胶-凝胶法制备了一种新型的手性整体柱，并以3-环氧丙氧丙基三甲氧基硅烷和L-苯丙氨酰胺为间隔基，对整体柱进行了化学修饰，成功地应用于丹磺酰氨基酸的配体交换-毛细管电色谱（LE-CEC）对映体分离。配体交换手性固定相（LE-CSP）经Cu（II）水溶液处理后，表面带正电荷，在外加电场作用下，LE-CSP表面产生从阴极到阳极的电渗流。发现该体系的稳定性取决于所施加的电场强度和移动的相的组成。随着移动的相pH值的升高，流动相的pH值有降低的趋势。扫描电子显微镜显示，该手性整体柱具有连续的骨架和大的通孔结构。在pH5.5，乙腈/0.50 mM Cu（Ac）（2）-50 mM NH_4Ac（7：3）为移动的流动相下，Dns-DL-Leu的分离效率（理论塔板数）对D-对映体可达9.0 × 10 ~（4）板m ~（-1），对L-对映体可达6.6 × 10 ~（4）板m ~（-1）。CEC用常规毛细管电泳设备进行，而不对毛细管末端加压。操作过程中，在对移动的相脱气并调节色谱柱后，未形成气泡。
A new type of chiral monolithic column was successfully developed for the enantioseparation of dansyl amino acids by ligand exchange-capillary electrochromatography (LE-CEC) in this work, The monolithic column matrix was prepared by a sol-gel process and then chemically modified with the spacer (3-glycidoxypropyl)trimethoxysilane and the chiral selector L-phenylalaninamide. After being conditioned with Cu(II) aqueous solution, the ligand exchange-chiral stationary phase (LE-CSP) possesses positive charges, When the external electric field was applied in CEC, electroosmotic flow (EOF) was generated on the surface of LE-CSP in the direction from the cathode to the anode. The EOF was found to be dependent on the applied electric field strength and the composition of the mobile phase. With the increase of pH of the mobile phase, the EOF showed a tendency to decrease. Scanning electron microscopy showed that the chiral monolithic column has a continuous skeleton and large through-pore structure. The separation efficiency (theoretic plate numbers) for the separation of Dns-DL-Leu reached up to 9.0 x 10(4) plates m(-1) for the D-enantiomer and 6.6 x 10(4) plates m(-1) for the L-enantiomer, by using pH 5.5, acetonitrile/0.50 mM Cu(Ac)(2)-50 mM NH4Ac (7:3) as mobile phase, The reproducibility and life-time were satisfactory. CEC was carried out with conventional capillary electrophoresis equipment without pressurizing the ends of the capillary. No bubble was formed during the operation, after degassing the mobile phase and conditioning the column.