对毛细管电泳法分离15种核苷类化合物所用的不同缓冲液体系进行了系统比较,确定不同模式毛细管电泳法分析多种核苷类化合物的最适合背景缓冲液体系(BGE)。分别以四硼酸钠、磷酸氢二钠、乙酸钠、碳酸氢钠、乙酸铵和乙二胺(DEA)为背景电解质,对毛细管区带电泳(CZE)、毛细管电泳-电喷雾飞行时间质谱(CE-ESI-TOF/MS)以及胶束电动毛细管电泳(MEKC)3种模式进行比较,并对其中几种优势缓冲体系进行了优化。结果表明,CZE模式下使用四硼酸钠和磷酸氢二钠缓冲体系无法同时分离15种核苷类化合物,因此只适用于分析核苷类化合物数量较少的样品。而使用含有2%丙酮的300 mmol/L DEA能完全分开15种核苷类化合物,且分辨率和峰形良好。MEKC模式下,以25 mmol/L磷酸氢二钠(添加70 mmol/L十二烷基磺酸钠(SDS))为缓冲盐的分离结果最佳,并且此方法能成功应用于海洋生物海葵中核苷类化合物的分离。CE-ESI-TOF/MS分析中,以20 mmol/L乙酸铵(pH 10.0)为背景电解质,正离子模式检测,15种核苷类化合物的质谱信号均良好,检测灵敏度明显优于文献中报道的使用DEA缓冲体系的结果。本研究阐明了不同缓冲体系对15种核苷类化合物分离的适用性,为毛细管电泳技术在复杂基质中多种核苷类化合物的分离方法中的应用奠定了基础。
The most suitable background electrolytes(BGEs) for simultaneous separation of 15 nucleosides by different modes of capillary electrophoresis(CE) were obtained.Various modes of CE were performed including capillary zone electrophoresis(CZE),capillary electrophoresis-electrospray ionization-time of flight mass spectrometry(CE-ESI-TOF/MS) and micellar electrokinetic chromatography(MEKC).The electrolyte buffers using sodium tetraborate decahydrate,disodium hydrogen phosphate,sodium acetate,sodium bicarbonate,ammonium acetate or 1,2-diamino-ethane(DEA) were tested,and the best of them were systematically optimized.In CZE mode,the nucleosides could not be separated completely with sodium tetraborate decahydrate or disodium hydrogen phosphate as BGEs,demonstrating the limited applicability of the two buffer systems for complex samples.However,with 300 mmol/L DEA(containing 2% acetone) as BGE,15 nucleosides could be separated with good resolution and peak shape,which proved that the DEA buffer was most suitable in CZE.The best buffer system in MEKC mode was 25 mmol/L disodium hydrogen phosphate with 70 mmol/L sodium dodecyl sulfate(SDS),and it was successfully applied for the separation of the nucleosides in Chinese Anthopleura lanthogrammica Berkly.The optimum buffer system for CE-ESI-TOF/MS analysis was 20 mmol/L ammonium acetate(pH 10.0).In the positive ion mode,the MS signals of each compound were better than those in the literature using DEA as BGE.The results of this study demonstrated the applicability of different buffer systems for the simultaneous separation of 15 nucleosides,and were helpful for the development of CE method in complex sample separation.