Li J, Ding W, Fritz J S
Ames Laboratory, US Department of Energy, IA 50011, USA.
J Chromatogr A. 2000 May 26;879(2):245-57. doi: 10.1016/s0021-9673(00)00296-x.
Capillary electrophoresis (CE) with a water-soluble ion-exchange polymer in the background electrolyte is very efficient for the separation of organic and inorganic anions because the ion-exchange selectivity, as well as differences in electrophoretic mobility, can be used for separating sample ions. Poly(diallyldimethylammonium chloride) (PDDAC) was employed for this purpose. A very stable electroosmotic flow was obtained between pH 2.3 and 8.5 due to the strong adsorption of PDDAC onto the capillary wall. The effect of ion exchange on the migration of sample anions and their separation was controlled by varying the concentration of PDDAC, the concentration and the type of salt used in the CE background electrolyte. Addition of organic solvent (e.g., acetonitrile) could also modify the sample migration and the separation. Baseline separations were obtained for anions with very similar mobilities, such as bromide and iodide, naphthalenesulfonates, and bi- and tricarboxylic acids. Typical separation efficiencies were between 195,000 and 429,000 theoretical plates per meter. Ten replicate separations gave an average RSD of 1.0% for migration times of the sample anions studied. Excellent separations were obtained for a variety of samples, including a separation of 17 inorganic and organic anions in less than 6 min.
在背景电解质中使用水溶性离子交换聚合物的毛细管电泳（CE）对有机和无机阴离子的分离非常有效，因为离子交换选择性以及电泳迁移率的差异都可用于分离样品离子。聚二烯丙基二甲基氯化铵（PDDAC）被用于此目的。由于PDDAC在毛细管壁上的强烈吸附，在pH 2.3至8.5之间获得了非常稳定的电渗流。通过改变PDDAC的浓度、CE背景电解质中使用的盐的浓度和类型来控制离子交换对样品阴离子迁移及其分离的影响。添加有机溶剂（如乙腈）也可以改变样品的迁移和分离。对于迁移率非常相似的阴离子，如溴化物和碘化物、萘磺酸盐以及二元和三元羧酸，实现了基线分离。典型的分离效率为每米195,000至429,000理论塔板数。对所研究的样品阴离子的迁移时间进行十次重复分离，平均相对标准偏差为1.0%。对于各种样品都获得了出色的分离效果，包括在不到6分钟内分离17种无机和有机阴离子。
