Image charge detection mass spectrometry: pushing the envelope with sensitivity and accuracy
John W Smith1, Elizabeth E Siegel, Joshua T Maze
1Chemistry Department, Indiana University, Bloomington, Indiana 47401, USA.
Analytical Chemistry
|January 14, 2011
Summary
A new charge detection mass spectrometer (CDMS) achieves unprecedented sensitivity for measuring single macroions. This advancement enables more accurate mass analysis of large molecules like poly(ethylene oxide).
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Polymer Science
Background:
- Charge detection mass spectrometry (CDMS) is a powerful technique for analyzing large ions.
- Previous CDMS instruments had limitations in sensitivity and mass accuracy for single macroions.
Purpose of the Study:
- To describe a novel charge detection mass spectrometer (CDMS) with enhanced sensitivity and mass accuracy.
- To demonstrate the capability of the improved CDMS for analyzing single macroions.
Main Methods:
- Utilized an image charge detector array with 22 detectors, divided into two groups at different potentials.
- Employed a correlation approach for signal analysis to determine ion velocities and charge.
- Calculated mass using detector signals, velocities, charge, and voltage differences.
Main Results:
- Successfully measured reliable masses for single macroions, an order of magnitude smaller than previously possible with CDMS.
- Presented mass, m/z, and charge distributions for 300 kDa poly(ethylene oxide) (PEG).
- Observed a primary mass distribution peak around 300 kDa, with additional broad peaks at 100 and 500 MDa, likely due to PEG aggregates.
Conclusions:
- The novel CDMS design significantly improves sensitivity and mass accuracy for single macroion analysis.
- The instrument is capable of characterizing polymer distributions and identifying aggregate species.
- This technology opens new avenues for high-resolution mass spectrometry of large biomolecules and polymers.
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