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Fluorometric beam profiling of UV MALDI lasers.
Rory T Steven1, Andrew D Palmer, Josephine Bunch
1PSIBS Doctoral Training Centre, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
Summary
A new, low-cost fluorometric method accurately measures laser beam profiles for matrix assisted laser desorption ionization mass spectrometry (MALDI-MS). This technique aids in understanding laser-sample interactions and improving MALDI-MS experiments.
Area of Science:
- Analytical Chemistry
- Spectroscopy
- Mass Spectrometry
Background:
- Laser beam profile is critical for matrix assisted laser desorption ionization mass spectrometry (MALDI-MS).
- Accurate beam profiling is essential for reproducible MALDI-MS results.
- Existing methods for beam profiling can be costly or complex.
Purpose of the Study:
- To present a simple, low-cost fluorometric laser beam profiling technique.
- To compare the fluorometric method with a commercial system for Nd:YVO4 laser profiling.
- To assess the accuracy of beam dimensions measured by ablation versus fluorometry.
Main Methods:
- Developed and applied a fluorometric laser beam profiling technique.
- Compared beam profiles from the fluorometric method and a commercial system.
- Investigated beam profile variations for an Nd:YVO4 laser (1-25 kHz).
- Compared in-source beam dimensions with ablation data from α-cyano-4-hydroxycinnamic acid (CHCA) thin films.
Main Results:
- The fluorometric method provides comparable beam profile information to commercial systems.
- Area estimation by ablation was 1.6 times smaller than that from the fluorometric method.
- Beam profile variations were observed with changes in laser frequency.
Conclusions:
- The fluorometric technique is a viable, cost-effective alternative for laser beam profiling in MALDI-MS.
- Accurate beam profile measurement is crucial for determining laser fluence in MALDI-MS.
- Discrepancies between ablation and fluorometric methods highlight the need for careful beam characterization.
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