Extractive-liquid sampling electron ionization-mass spectrometry (E-LEI-MS): a new powerful combination for direct...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Spectroscopy

Background:

• Real-time analysis is crucial in modern analytical chemistry for rapid results.
• Direct mass spectrometry (DMS) and ambient ionization mass spectrometry (AIMS) are key techniques for fast analysis.
• Existing methods often require extensive sample preparation, limiting analysis speed.

Purpose of the Study:

• To present a proof-of-concept for Extractive-liquid sampling electron ionization-mass spectrometry (E-LEI-MS).
• To demonstrate E-LEI-MS for targeted/non-targeted analysis and semi-quantitative detection.
• To showcase the coupling of ambient sampling with electron ionization (EI) for direct sample analysis.

Main Methods:

• Utilized a novel E-LEI-MS system combining ambient sampling with an electron ionization source.
• Employed a micromanipulator for precise (x,y,z) positioning of the sampling tip.
• Operated the mass spectrometer in scan or selected ion monitoring (SIM) modes.

Main Results:

• Generated highly informative EI mass spectra for compound identification.
• Successfully applied E-LEI-MS to diverse samples: pharmaceutical tablets, fruit peel (pesticides), banknotes (cocaine), and painting surfaces.
• Determined the spatial distribution of analytes in forensic and artwork applications.

Conclusions:

• E-LEI-MS provides a viable strategy for rapid, direct analysis with minimal sample preparation.
• The technique offers versatile applications across various fields, including forensics and art conservation.
• E-LEI-MS enables both qualitative and semi-quantitative analysis, with potential for spatial mapping.