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Published on: September 5, 2014
Unexpected analyte oxidation during desorption electrospray ionization-mass spectrometry
Sofie P Pasilis1, Vilmos Kertesz, Gary J Van Berkel
1Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6131, USA.
Analytical Chemistry
|January 11, 2008
Summary
Oxidative modification of analytes during desorption electrospray ionization-mass spectrometry (DESI-MS) is influenced by sample aging, lighting, and spray voltage. Controlling these factors can minimize unwanted oxidation during analysis.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Surface Analysis
Background:
- Desorption electrospray ionization-mass spectrometry (DESI-MS) is a powerful technique for analyzing surface-spotted samples.
- Oxidative modification of analytes, observed as oxygen addition reactions, can complicate DESI-MS analysis.
Purpose of the Study:
- To investigate the factors influencing oxidative modification of analytes during DESI-MS.
- To identify operational parameters that minimize or maximize analyte oxidation.
Main Methods:
- Studied the effects of sample aging, ambient environment, spray voltage, surface concentration, and surface type on analyte oxidation.
- Utilized tamoxifen and reserpine as model analytes.
- Varied spray solvent flow rate and incorporated a redox buffer (hydroquinone).
Main Results:
- Sample exposure to air and light increased oxidation.
- Higher spray voltage led to increased analyte oxidation.
- Lower analyte surface concentration resulted in more significant oxidation.
- Increased solvent flow rate and hydroquinone addition decreased oxidation.
Conclusions:
- Analyte oxidation in DESI-MS is influenced by multiple factors including sample handling and instrument parameters.
- Recommendations for DESI-MS operation are provided to mitigate unwanted oxidative reactions.
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