Suppression of electroosmotic flow and its application to determination of electrophoretic mobilities in a poly(vinylpyrrolidone)-coated capillary
Suppression of electroosmotic flow and its application to determination of electrophoretic mobilities in a poly(vinylpyrrolidone)-coated capillary
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DOI：
10.1016/j.chroma.2005.08.062
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发表时间：
2006-02-17
影响因子：
4.1
通讯作者：
Imasaka, T
中科院分区：
文献类型：
--
作者：
Kaneta, T;Ueda, T;Imasaka, T
采用亲水性聚合物聚乙烯吡咯烷酮（PVP）抑制电渗流。用PVP水溶液填充毛细管以用PVP涂覆毛细管壁;然后用不含PVP的迁移缓冲溶液替换PVP溶液。研究了三种不同分子量的PVP。随着PVP分子量的增加，抑制聚合的效果更好。涂层毛细管中的pH值比裸毛细管小10倍，并且在6-8的pH范围内恒定。即使在迁移缓冲液中不加入PVP时，抑制的迁移也是稳定的。然而，当十二烷基硫酸钠加入到迁移缓冲液中时，迁移率显著增加。该方法适用于确定无机阴离子的电泳迁移率，具有负的电泳迁移率大于电渗迁移率的裸毛细管。基于电流与电泳迁移率之间的线性关系，提出了一种测定电泳迁移率的新方法。电泳迁移率与电流成正比。因此，回归方程的截距代表室温下的电泳迁移率。电泳迁移率与绝对电泳迁移率吻合良好。(c)2005 Elsevier B. V.保留所有权利。
A hydrophilic polymer, poly(vinylpyrrolidone) (PVP), was employed for suppressing the electroosmotic flow (EOF). A capillary was filled with aqueous PVP solution for coating the capillary wall with PVP; the PVP solution was then replaced by a migration buffer solution containing no PVP. Three types of PVP with different molecular weights were examined. The EOF was suppressed more effectively as the molecular weight of PVP increased. The EOF in the coated capillary was similar to 10-fold smaller than that of a bare capillary and was constant in the pH range of 6-8. The suppressed EOF was stable even when no PVP was added to the migration buffer. However, the EOF increased significantly when sodium dodecyl sulfate was added into the migration buffer. The method was applied for determining the electrophoretic mobilities of inorganic anions that have negative electrophoretic mobilities larger than the electroosmotic mobility of the bare capillary. A novel method for determining the electrophoretic mobilities was proposed based on the linear relationship between electric current and electrophoretic mobility. The electrophoretic mobility was proportional to the electric current. Therefore, the intercept of the regression equation represents the electrophoretic mobility at room temperature. The electrophoretic mobilities were in good agreement with the absolute electrophoretic mobilities. (c) 2005 Elsevier B.V. All rights reserved.