Broad-band ion accumulation with an internal source MALDI-FTICR-MS
1Department of Chemistry, University of Georgia, Athens 30602-2556, USA.
Analytical Chemistry
|January 5, 2001
Summary
A novel ion accumulation method enhances signal intensity and signal-to-noise ratios for analyzing low-level samples. This technique improves mass accuracy by enabling post-accumulation internal calibration, outperforming traditional signal averaging.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Instrumentation
Background:
- Matrix-assisted laser desorption/ionization (MALDI) is a common ionization technique.
- Signal averaging is frequently used to improve signal-to-noise ratios in mass spectrometry.
- Accurate quantification of low-level analytes remains a challenge.
Purpose of the Study:
- To develop a new method for accumulating ions from multiple MALDI events.
- To improve signal intensity and signal-to-noise ratio for low-level sample analysis.
- To enhance mass accuracy using an internal calibration strategy.
Main Methods:
- Ions from multiple MALDI events were accumulated in a Fourier transform ion cyclotron resonance (FT-ICR) analyzer cell.
- Signal intensity and signal-to-noise ratio were measured as a function of laser shots.
- Calibrant ions were introduced into the cell after analyte accumulation for internal calibration.
Main Results:
- Signal intensity and signal-to-noise ratio increased proportionally with the number of laser shots.
- The new accumulation method significantly improved analysis of low-level samples compared to signal averaging.
- Excellent mass accuracy was achieved by eliminating space charge effects through post-accumulation calibration.
Conclusions:
- The described ion accumulation method offers substantial improvements for analyzing low-level samples.
- This technique provides enhanced signal-to-noise ratios and superior mass accuracy.
- The ability to introduce calibrants post-accumulation simplifies internal calibration and improves quantitative analysis.
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