毛细管电泳-柱端安培检测中分离毛细管与检测电极对接方式比较的研究

Study on the Optimization of Coupling Forms between Capillary and Electrode in Capillary Electrophoresis with Amperometric Detection

针对目前毛细管电泳中普遍采用的水平式和直立式两种柱端安培检测形式,在各种可能的对接角 度下,以邻苯二酚、间苯二酚和对苯二酚3种二酚作为分离分析测试对象,对分离毛细管与检测电极的对接方 式进行了优化比较,并对每一种对接方式的分析特性进行了测试。结果表明:在以3种典型的方式对接时,分 离毛细管与检测电极为倒直立式对接时,获得的检测灵敏度最高,响应电流最大,水平式次之,直立式最小。

Contraposing to the parallel and vertical amperometric detection existing at present, the various angles of the comparative position between the working electrode and separation capillary was studied by using catechol, resorcinol, and hydroquinone as the analytes. Under the elected conditions, the analytical characteristics of the methods were also studied for three typical forms of jointing of electrode and capillary. The data obtained from experiments demonstrate that the different coupled form of detection electrode with separation capillary may cause different results for the end-column amperometric detection in capillary electrophoresis (CE-AD). The detection currents for 1.0 mmol/L resorcinol are about 242, 344 and 464 nA for the nertical, paralled and reverse vertical, respectively. Similar results are also shoum in the experiments for the other two anlytes. Comparing the three jointing forms, it was found that the reverse vertical is the best, the vertical is the poorest, and the parallel is between the two previous. All these are of significance for the optimization of the CE-AD technology.