A Method for Isomer Differentiation by Combining Gas Chromatography, Selective Self-Ion/Molecule Reaction, Tandem Mass Technique (GC/SSIMR/MS/MS) in an Ion Trap Mass Spectrometer

• Main Authors: Li, Hsiao Wei, 李孝偉
• Other Authors: Wu, Hui-Fen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/18371726676195505702

碩士 === 淡江大學 === 化學學系 === 90 === A method for isomer differentiation based on Selective Self-Ion/Molecule Reactions (SSIMR) in an internal source ion trap mass spectrometer is demonstrated. The successfully combining GC/SSIMR/MS/MS technique to differentiate isomers is also demonstrated in this thesis. SSIMR product ions were produced between four different isomers (C5H7N). For 1-methylpyrrole, SSIMR leads to the formation of the molecular ion as the base peak due to the lower ionization energy; the other three isomers produces [M+H]+ as base peaks. By combining collisionally activated dissociation (CAD) techniques, isolation experiments and semi-empirical calculations, the possible reaction mechanisms for formation of the [M+CH]+ ions for 1-methylpyrrole is also proposed. In addition, other ion trap-related techniques such as energy resolved mass spectrometry (ERMS) and time resolved mass spectrometry (TRMS) are also applied to perform isomer differentiation for these isomers via SSIMR in the ion trap mass spectrometry. This study introduces a novel and powerful separation technique by combination of the traditional GC, MSn and the newly development of SSIMR for the ion trap mass spectrometry. The application of SSIMR for isomer differentiation present in this study provides the advantages including simplicity, efficiency, speed, convenience and low-cost. The contribution of this thesis is to demonstrate a new analytical application involving the use of SSIMR for isomer differentiation in the future.