Institute of Chemistry, Saint Petersburg State University, Saint Petersburg, Russia.
Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academу of Sciences, Moscow, Russia.
Electrophoresis. 2020 Jun;41(12):1031-1038. doi: 10.1002/elps.201900416. Epub 2020 May 17.
The first example of application of nanosized polystyrene-based cation exchanger (NSCE) with sulfo groups as a dynamic coating of capillary walls was demonstrated. The conditions of dynamic coating formation were optimized and ensured the long-term stability of the coating. Capillary-to-capillary and day-to-day repeatabilities were 4% and 3%, correspondingly. The NSCE coating stability at various pH and influence of pH on the EOF mobility were investigated. The developed NSCE-modified coated capillaries provided improved resolution (R = 0.9-3.2 for catecholamines and R = 1.7-2.8 for amino acids) and efficiencies (330-520 ×10 t.p./m) of basic analytes, which are 1.5 times higher compared to untreated capillary. The optimized conditions were as follows: 50 mM phosphate buffer solution at pH 2.2 with 5 μM NSCE. The effect of the NSCE concentration in BGE on the electrophoretic mobilities of the analytes was investigated. The various online concentration techniques were tested in order to decrease the LODs. The simultaneous application of NSCE capillaries and field-amplified sample stacking provided the lowest LODs of catecholamines and amino acids and allowed to determine these analytes in human urine.
首次将带有磺酸基团的纳米级聚苯乙烯基阳离子交换剂 (NSCE) 用作毛细管壁的动态涂层进行了应用实例展示。对动态涂层形成条件进行了优化，保证了涂层的长期稳定性。相应地，毛细管到毛细管和每天的重复性分别为 4%和 3%。研究了 NSCE 涂层在不同 pH 值下的稳定性以及 pH 值对电渗流迁移率的影响。开发的 NSCE 改性涂层毛细管提高了碱性分析物的分辨率（儿茶酚胺的 R = 0.9-3.2，氨基酸的 R = 1.7-2.8）和效率（330-520×10 t.p./m），与未处理的毛细管相比提高了 1.5 倍。优化条件如下：pH 2.2 的 50 mM 磷酸盐缓冲溶液，含 5 μM NSCE。研究了 BGE 中 NSCE 浓度对分析物电泳迁移率的影响。为了降低检测限，测试了各种在线浓缩技术。同时应用 NSCE 毛细管和场放大样品堆积，提供了最低的儿茶酚胺和氨基酸检测限，并允许在人尿中检测这些分析物。
