用聚丙烯酰胺交联涂层毛细管电泳柱分离无机阴离子

Separation of Some. Inorganic Anions Using Coated Capillary by Capillary Electrophoresis

研究了用涂层柱分离Ｉ－，ＮＯ２－，ＮＯ３－，ＳＣＮ－，ＭｏＯ４２－等５种具有紫外吸收的阴离子 的毛细管电泳方法。采用涂层柱可以有效地抑制电渗流，因此无需在载体电解质溶液中加入 电渗流改性剂。其优越性在于改善了由于电渗流改性剂与体积较大的阴离子发生离子对相 互作用所导致的峰形拖尾现象，有助于准确定量。考察了分离电压、缓冲液浓度、缓冲液ｐＨ 值对分离的影响，并对涂层柱的稳定性进行了考察，迁移时间的相对标准们差在２％以内。连 续使用一个多月，共进样５００余次（在ｐＨ ２．５～８的缓冲溶液下操作）仍保持完好的性能，表 明该方法具有良好的实用价值。

A new method for separation of anions with capillary electrophoresis has been studied. In this method cross-linked and bonded polyacrylamide coated capillary was used to depress the electroosmotic flow(EOF), and five inorganic anions I-,NO-, NO-, SCN- and MoO4-2- were successfully separated. The coated capillary can effectively depress EOF with- out the use of an EOF modifier, thus avoiding the ion pair interaction between EOF modifier and anions with large ion radius, such as I - and SCN-, because the ion pair interaction will lead to difficult quantitation due to peak tailing, The effects of pH and concentration of back- ground electrolytes on separation were investigated. Good reproducibility of migration time of 5 anions was obtained (RSD%<2). After continuous use for 4 months, with running more than 500 times (in the range of pH2. 8-8), the coated capillary still has good performance for anion separation.