A Gold Foil Covered Fused Silica Capillary Tip as a Sheathless Interface for Coupling Capillary Electrophoresis-Mass Spectrometry
A Gold Foil Covered Fused Silica Capillary Tip as a Sheathless Interface for Coupling Capillary Electrophoresis-Mass Spectrometry
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金箔覆盖的熔融石英毛细管尖端作为毛细管电泳-质谱联用的无鞘接口
DOI：
10.1016/j.chroma.2020.461215
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Kang Jingwu
中科院分区：
文献类型：
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作者：
Zhang Hanzhi;Lou Chunli;Li Jing;Kang Jingwu
提出了一种用于毛细管电泳-质谱联用的无鞘层柱上电喷雾离子发射体的制备方法。发射体直接制造在分离毛细管的出口端，其用HF溶液蚀刻成对称尖端。头端覆盖一小片金箔，用环氧树脂胶固定，以实现电接触。这种制备的电喷雾发射器可以产生一个稳定的电喷雾信号在很宽的范围内的流速从50 nL/min至800 nL/min。通过使用四种生物碱的分离与鞘层接口的CE-MS的性能进行了评价。结果发现，毛细管上的多重聚电解质涂层产生的强电渗流对于维持稳定的MS信号是必要的。考察了电泳缓冲液组成、浓度和分离电压对电喷雾离子化信号强度的影响。生物碱的绝对检测限以fmol水平确定。此外，CE-MS还用于胰蛋白酶消化细胞色素C和小分子有机阴离子的分析。该发射体性能非常稳定，寿命至少为180 h。
A method for the preparation of an on-column ESI emitter used as the sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry (MS) was developed. The emitter was directly fabricated at the outlet end of the separation capillary which was etched with HF solution to a symmetrical tip. The tip was covered with a small piece of gold foil which was fixed by epoxy resin glue for electrical contact. Such a prepared ESI emitter can produce a stable ESI signal over the wide range of flow rate from 50 nL/min to 800 nL/min. The performance of the CE-MS with the sheathless interface was evaluated by using the separation of four alkaloids. It was found that the strong electroosmotic flow produced by the multiple polyelectrolyte coating on the capillary is necessary for maintaining a stable MS signal. Effect of the running buffer composition, concentration and the CE separation voltages on the ESI signal strength were investigated. The absolute detection limits for the alkaloids was determined as fmol level. Moreover, the CE-MS was applied for the analyses of trypsin digestion of cytochrome C and small molecular organic anions. The emitter performed very stable with a lifetime of at least 180 h.