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Atmospheric-pressure Molecular Imaging of Biological Tissues and Biofilms by LAESI Mass Spectrometry
Published on: September 3, 2010
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Solvent gradient electrospray for laser ablation electrospray ionization mass spectrometry
1Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington, DC 20052, USA. vertes@gwu.edu.
The Analyst
|July 19, 2017
Summary
Gradient laser ablation electrospray ionization (g-LAESI) uses a dual-solvent spray to enhance molecular coverage. This new method improves the detection of diverse compounds in complex biological samples.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Biotechnology
Background:
- Electrospray ionization techniques often use a single solvent, limiting the analysis of complex samples with varying compound polarities and solubilities.
- Traditional laser ablation electrospray ionization (LAESI) struggles with diverse analyte solubility due to fixed spray solution composition.
Purpose of the Study:
- To develop a novel gradient electrospray method for enhanced molecular coverage in mass spectrometry.
- To improve the detection capabilities of LAESI for complex biological samples containing compounds of diverse polarity.
Main Methods:
- A new variant of LAESI, termed gradient LAESI (g-LAESI), was developed using a two-barrel theta glass capillary.
- High voltages applied to the capillary barrels were scanned to create a gradient electrospray by mixing two different solvents.
- g-LAESI-MS was applied to analyze chemical standards and compounds from Escherichia coli cell pellets.
Main Results:
- g-LAESI-MS achieved dynamic ranges and limits of detection comparable to conventional LAESI-MS.
- The method enabled the simultaneous detection of polar and less polar compounds.
- Demonstrated successful analysis of diverse chemical standards and complex biological samples.
Conclusions:
- Gradient electrospray, by varying spray solution composition, enhances analyte solubility and broadens molecular coverage.
- g-LAESI-MS offers a powerful tool for direct analysis of complex biological samples, overcoming limitations of fixed-composition electrospray methods.
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