降低對掌選擇劑於環糊精修飾毛細電泳/電灑法質譜儀訊號抑制之研究

Alleviation of Ion Suppression Effect in Cyclodextrin Electrokinetic Chromatography/ Electrospray Ionization Mass Spectrometry Due to Chiral Selector

洪偲華(Sih-Hua Hung)

指導教授 ： 何國榮

國立臺灣大學/理學院/化學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.03154

摘要

本研究提出一新概念成功地銜接高濃度環糊精修飾毛細電泳(CD-EKC)與電灑法質譜(ESI-MS)，改善帶負電荷的環糊精(sulfated β-cyclodectrin, S-β-CD)對分析物訊號造成抑制的問題。此策略類似實驗室先前已開發的液體結合-低流速鞘流界面(liquid-junction/low-flow interface)，施加正向電場於銜接管中，使得負電荷環糊精可以藉由電場作用停留於液體結合槽中，且為降低環糊精與分析物之間的作用力，在液體結合槽中添加20 % ACN，因此分析物可藉由電滲流的帶動往質譜端被偵測。此外抬高進樣端溶槽可避免液體結合槽中的有機相(ACN)隨著電滲流入分離管，破壞分析物與環糊精之間的作用而影響分離。在分離管部份使用反向電場進行分離，環糊精可持續由後方緩衝溶液槽往前補充，因此分離管柱仍保有完整的環糊精區帶，維持一定的分離效率。此方法不僅維持原有高濃度環糊精良好分離效率，同時也成功地減少環糊精造成的訊號抑制。

關鍵字

環糊精 ； 毛細電泳 ； 質譜 ； 液體結合-低流速鞘流界面

並列摘要

A method capable to couple high concentration cyclodextrin electrokinetic chromatography with electrospray ionization mass spectrometry (CD/EKC-ESI/MS) detection without suffering ion signal suppression was proposed. The concept of liquid junction/low flow interface was employed in this work. A normal polarity was applied across the connecting capillary; therefore, the negative sulfated β-cyclodectrin (S-β-CD) could be remained in liquid junction reservoir due to the electric field. Running buffer containing 20% acetonitrile was filled in the liquid junction reservoir. Because of acetonitrile, the affinity of the analyte with S-β-CD could be reduced, so that the analyte could migrated toward the MS detector by electroosmotic flow. The inlet of capillary electrophoresis was elevated to avoid ACN from entering the separation column to deteriorate the interaction between S-β-CD and the analyte during the capillary electrophoresis(CE) separation. Because the reversed polarity was applied across the separation column, the S-β-CD zone could be filled in the CE separation column to preserve the separation efficiency. Both good chiral separation efficiency and low ion signal suppression could be achieved by this approach.

並列關鍵字

cyclodextrin ； capillary electrophoresis ； mass spectrometry ； liquid junction/low flow interface

參考文獻

4. Gel-Moreto, N.; Streich, R.; Galensa, R. Electrophoresis 2003, 24, 2716.

5. Asztemborska, M.; Miskiewicz, M.; Sybilska, D. Electrophoresis 2003, 24, 2527.

6. Lantz, A. W.; Rozhkov, R. V.; Larock, R. C.; Armstrong, D. W. Electrophoresis 2004, 25, 2727.

7. Park, H., Jung, S. Electrophoresis 2005, 26, 3833.

8. Chang, W. Y., Master Thesis, National Taiwan University, Taipei, Taiwan, 2006.