Kim Jihye, Chun Man-Seog, Choi Kihwan, Chung Doo Soo
Department of Chemistry, Seoul National University, Seoul, Korea.
Electrophoresis. 2009 Mar;30(6):1046-51. doi: 10.1002/elps.200800396.
Large volume stacking using an EOF pump (LVSEP) is realized for CE with ESI-MS. In LVSEP of anions, the adverse effects of a long sample matrix plug were overcome by pumping the plug out of the separation capillary to the inlet vial using the EOF under a potential of reverse polarity. Therefore, it was necessary to supply a backup run buffer from the outlet end of the capillary, which was not trivial in most ESI-MS configurations. We solved this difficulty simply by placing a vial supplying a backup run buffer during the matrix removal and sample stacking process. In addition, methanol was used as the run buffer solvent enabling a bare fused-silica capillary to meet the requirement of suppressed EOF. This LVSEP CE/ESI-MS has been successfully applied to six anionic analytes, achieving 400-fold enrichment in the detection sensitivity by using a conventional sheath liquid CE/ESI-MS interface without any physical modification.
利用电渗流泵实现了用于毛细管电泳与电喷雾质谱联用的大体积堆积（LVSEP）。在阴离子的LVSEP中，通过在反相极性电势下利用电渗流将长的样品基质塞从分离毛细管泵出到进样瓶中，克服了长样品基质塞的不利影响。因此，有必要从毛细管的出口端供应备用运行缓冲液，这在大多数电喷雾质谱配置中并非易事。我们通过在基质去除和样品堆积过程中放置一个供应备用运行缓冲液的小瓶，简单地解决了这个难题。此外，使用甲醇作为运行缓冲液溶剂，使得裸熔融石英毛细管能够满足抑制电渗流的要求。这种LVSEP毛细管电泳/电喷雾质谱已成功应用于六种阴离子分析物，通过使用传统的鞘液毛细管电泳/电喷雾质谱接口，在无需任何物理修改的情况下，检测灵敏度提高了400倍。
