On-Line Synthesis and Analysis by Mass Spectrometry
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- 作者：Ryan M. Bain ; Christopher J. Pulliam ; Shannon A. Raab ; R. Graham Cooks
- 刊名：Journal of Chemical Education
- 出版年：2015
- 出版时间：December 8, 2015
- 年：2015
- 卷：92
- 期：12
- 页码：2146-2151
- 全文大小：324K
- ISSN：1938-1328
文摘
In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction as a function of the electrospray variable parameters. This reaction allows students to gauge the effects of the spray variables while observing the enhanced reaction rate through product analysis in the charged microdroplets. Soft ionization techniques used in conjunction with collision-induced dissociation provide students experience with full scan MS to infer reaction progress and collision-induced fragmentation patterns for structural analysis. The experiment as a whole combines the physical phenomena of electrospray, Hantzsch chemical reactivity, and analytical measurements involving use of an ion trap mass spectrometer.