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Published on: July 12, 2013
Enhanced ion signals in desorption electrospray ionization using surfactant spray solutions
Abraham Badu-Tawiah1, R Graham Cooks
1Chemistry Department, Purdue University, West Lafayette, Indiana 47907, USA.
Summary
Adding surfactants to solvents in desorption electrospray ionization (DESI) significantly enhances ion signals. This optimization improves DESI-MS analysis for various compounds, including challenging hydrophobic analytes.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Surface Chemistry
Background:
- Solvent optimization is crucial for enhancing desorption electrospray ionization (DESI) efficiency.
- Surface tension of spray solvents significantly impacts ion signal intensity in DESI-MS.
Purpose of the Study:
- To investigate the effect of solvent surface tension on ion signals in DESI.
- To explore the use of surfactants in DESI spray solvents for improved analyte detection.
Main Methods:
- Utilized methanol/water solvent systems modified with low concentrations of surfactants.
- Analyzed various compounds including food chemicals, peptides, pharmaceuticals, and drugs of abuse using DESI-MS.
- Investigated the relationship between surface tension, droplet size, and surface area coverage.
Main Results:
- Addition of surfactants to methanol/water (1:1) solvent increased ion signals by over an order of magnitude.
- Reduced surface tension led to smaller spray droplets and increased surface area coverage, enhancing ionization.
- Enabled DESI-MS analysis of previously intractable analytes like melamine and hydrophobic sudan dyes.
Conclusions:
- Surfactant-mediated reduction of surface tension is an effective strategy for optimizing DESI solvents.
- This approach significantly boosts ion intensity and expands the range of detectable analytes in DESI-MS.
- Optimized DESI solvents with surfactants offer a powerful tool for analyzing diverse chemical compounds.
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