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Signal suppression in electrospray ionization Fourier transform mass spectrometry of multi-component samples
1Department of Chemistry and Biochemistry, University of Delaware, Newark 19716, USA.
Journal of Mass Spectrometry : JMS
|April 18, 2000
Summary
Fourier transform mass spectrometry (FTMS) is a powerful tool for biomolecule quantitation. However, complex mixtures can cause signal suppression due to ion-ion interactions, impacting accuracy.
Area of Science:
- Analytical Chemistry
- Biochemistry
- Mass Spectrometry
Background:
- Fourier transform mass spectrometry (FTMS) offers high resolution, mass range, and sensitivity for biomolecule analysis.
- Electrospray ionization (ESI) coupled with FTMS is explored for quantitative analysis of complex biological samples.
Purpose of the Study:
- To assess the applicability of ESI-FTMS for quantifying biomolecules in multi-component mixtures.
- To investigate signal suppression effects and mass discrimination in ESI-FTMS quantitative analysis.
Main Methods:
- Analysis of mixtures containing cytochrome c, angiotensin II, insulin, and lysozyme using ESI-FTMS.
- Examination of linear responses for single-component standards.
- Investigation of ion-ion interactions and trapping voltage effects on ion intensities.
Main Results:
- Linear responses were observed for single analytes within specific concentration ranges (0.031-3 microM for angiotensin II/insulin, 0.031-1 microM for cytochrome c/lysozyme).
- Signal suppression of smaller molecules by larger molecules was observed in mixtures, attributed to ion-ion interactions and selective ion loss.
- Mass discrimination effects dependent on trapping voltage were identified, particularly for ions differing by 30% or more in mass.
Conclusions:
- ESI-FTMS shows potential for biomolecule quantitation, but signal suppression in complex mixtures requires careful consideration.
- Ion-ion interactions and mass discrimination effects necessitate optimized experimental conditions for accurate quantification.
- Running samples and standards at a constant trapping potential is recommended for reliable ESI-FTMS quantitation.
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