Laser-induced electron capture mass spectrometry

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Spectroscopy

Background:

• Electron capture mass spectrometry (EC-MS) is a sensitive technique for detecting specific types of molecules.
• Traditional GC/EC-MS has limitations in the range of detectable analytes.
• Laser-induced techniques offer potential for enhanced sensitivity and broader applicability.

Purpose of the Study:

• To develop and report two new techniques for detecting electrophore-derivatized compounds using laser-induced electron capture time-of-flight mass spectrometry (LI-EC-TOF-MS).
• To demonstrate the sensitivity and applicability of these novel methods.
• To expand the range of analytes detectable by EC-MS.

Main Methods:

• Development of two LI-EC-TOF-MS techniques for electrophore detection.
• Technique 1: Analyte deposited in a matrix (e.g., benzo[ghi]perylene) with low ionization potential.
• Technique 2: Analyte deposited on a silver surface without matrix, utilizing instant ion desorption.

Main Results:

• Detection of 10 picomoles of 3-O-(pentafluorobenzyl)-alpha-estradiol at a signal-to-noise ratio (S/N) >= 50.
• Achieved high sensitivity with a small laser spot size (approx. 0.25% of sample spot).
• Demonstrated narrow peak widths (4 ns) in the absence of matrix, indicating rapid ion desorption.

Conclusions:

• Simple conditions enable sensitive detection of electrophores using routine TOF-MS equipment.
• These LI-EC-TOF-MS techniques significantly broaden the range of analytes (polarity and size) detectable by EC-MS.
• The findings present a valuable advancement over traditional GC/EC-MS methods.