Improving repeatability of capillary electrophoresis-a critical comparison of ten different capillary inner surfaces and three criteria of peak identification.

摘要: A poor repeatability of migration times caused by the fluctuations electroosmotic flow (EOF) is an inherent weakness capillary electrophoresis. Most researchers endeavor to prevent this problem using relative or various coatings which are expensive and not easy in comparison. Herein, we present original approach problem: apply a model sample designed induce significant EOF instability, order critically compare ten types with different physicochemical characteristics. Moreover, accompany modification evaluation criteria peak identification: time, ratio, electrophoretic mobility. Our results show great effectiveness dynamic coating stabilization times, average RSD(%) value reduced from 3.5% (bare silica capillary) down 0.5%. The good outcomes were also obtained for surfactant-modified amine capillaries. For capillaries exhibiting instability EOF, mobility turned out be more universal reliable criterion identification than time. It can explained intrinsic dependency ratio on change, should always considered during selection internal standard.