School of Pharmacy, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan.
J Chromatogr A. 2010 Jan 29;1217(5):715-21. doi: 10.1016/j.chroma.2009.12.018. Epub 2009 Dec 6.
Prepared multi-wall carbon nanotube (MWNT) materials, including untreated MWNT, HNO(3)-treated MWNT and HNO(3)-HCl-treated MWNT were covalently attached onto a silica-hydride-modified capillary by hydrosilation, using the abundant double bonds between the pentagon carbons in the MWNT structure. These MWNT-incorporated capillaries were characterized by SEM, ATR-IR and electroosmotic flow (EOF) measurements in phosphate buffers with a pH range of 3.7-9.3 and in the mixtures of acetonitrile modifier. The untreated capillary was assumed to carry some carboxylate groups formed on the non-acid-treated MWNTs, as it had higher EOF values than the hydride capillary. As the MWNTs were treated with HNO(3) and HCl solutions, the capillaries had increasingly higher EOF values. To examine the existence of an electrochromatography mechanism in the modified capillaries, a mixture of nucleosides and thymine was probed to check the velocity factor and retention factor. In addition to the pi-pi interaction between the probe solutes and the MWNT immobilized stationary phases; a reversed-phase mechanism could contribute to the chromatographic retention. For acidic tetracyclines, increasing the loadability of MWNTs resulted in a high retention factor and improved the separation resolution.
已制备的多壁碳纳米管（MWNT）材料，包括未经处理的 MWNT、HNO(3)-处理的 MWNT 和 HNO(3)-HCl-处理的 MWNT，通过硅氢加成反应共价键合到硅烷化修饰的毛细管上，利用 MWNT 结构中五边形碳之间丰富的双键。这些 MWNT 掺入的毛细管通过 SEM、ATR-IR 和在 pH 值为 3.7-9.3 的磷酸盐缓冲液中和在乙腈改性剂的混合物中的电渗流（EOF）测量进行了表征。未经处理的毛细管被认为带有一些在非酸处理的 MWNTs 上形成的羧酸盐基团，因为它具有比氢化毛细管更高的 EOF 值。随着 MWNTs 用 HNO(3)和 HCl 溶液处理，毛细管的 EOF 值越来越高。为了检查修饰毛细管中是否存在电色谱机制，探测了核苷和胸腺嘧啶的混合物，以检查速度因子和保留因子。除了探针溶质和固定在 MWNT 上的固定相之间的 pi-pi 相互作用外；反相机制可能有助于色谱保留。对于酸性四环素，增加 MWNTs 的负载能力会导致高保留因子并提高分离分辨率。
