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Fast Enzymatic Processing of Proteins for MS Detection with a Flow-through Microreactor
Published on: April 6, 2016
Off-line integration of CE and MALDI-MS using a closed-open-closed microchannel system
Johan Jacksén1, Thomas Frisk, Theres Redeby
1Department of Chemistry, Division of Analytical Chemistry, School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
Electrophoresis
|June 20, 2007
Summary
A novel technique for off-line hyphenation of capillary electrophoresis (CE) and MALDI-MS was developed. This method effectively analyzes proteins and demonstrates that capillary outer diameter impacts peak dispersion in CE-MS hyphenation.
Area of Science:
- Analytical Chemistry
- Separation Science
- Mass Spectrometry
Background:
- Capillary Electrophoresis (CE) and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) are powerful analytical techniques.
- Hyphenating CE with MALDI-MS offers enhanced separation and identification capabilities.
- Optimizing interfaces between CE and MALDI-MS is crucial for improving analytical performance.
Purpose of the Study:
- To present a new off-line hyphenation technique connecting CE and MALDI-MS.
- To investigate the electroosmotic flow (EOF) characteristics in the developed CE-MS interface.
- To evaluate the impact of capillary dimensions on peak dispersion and analyte signal distribution.
Main Methods:
- A novel interface was constructed by connecting two fused-silica capillaries via a silicon chip with an open microcanal.
- Electroosmotic flow (EOF) was measured using mesityloxide or leucine-enkephalin under conditions of neutral analyte charge.
- Peak dispersion was analyzed by varying the capillary outer diameter (150 µm vs. 375 µm) in a closed-open-closed system.
- Mass spectrometric analysis of model proteins (cytochrome c, lysozyme) was performed after CE separation.
Main Results:
- Experimental EOF values were found to agree with theoretical predictions.
- A capillary with a 375 µm outer diameter resulted in significantly higher peak dispersion compared to a 150 µm capillary due to increased dead volume.
- Separated analytes were successfully detected and their signal distribution profiles recorded across a 30 mm microcanal using MALDI-MS.
Conclusions:
- The developed off-line CE-MALDI-MS hyphenation technique is effective for protein analysis.
- Capillary outer diameter is a critical factor influencing peak dispersion in CE-MS hyphenation, with smaller diameters being preferable.
- The microcanal interface allows for spatial distribution analysis of separated analytes in MALDI-MS.
