MALDI Ion Trap Mass Spectrometer with Charge Detector for Large Biomolecule Detection

摘要

Up to now, all commercial matrix-assisted laser desorptionionization (MALDI) mass spectrometers still can notnefficiently analyze very large biomolecules. In this work,nwe report the development of a novel MALDI ion trapnmass spectrometer which can enrich biomolecular ionsnto enhance the detection sensitivity. A charge detector wasninstalled to measure the large ions directly. With thisndesign, we report the first measurement of IgM with thenmass-to-charge ratio (m/z) at 980 000. In addition,nquantitative measurements of the number of ions can benobtained. A step function frequency scan was first developednto get a clear signal in the m/z range from 200 000nto 1 000 000.