Visualization of Sampling and Ionization Processes in Scanning Probe Electrospray Ionization Mass Spectrometry

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Surface Science

Background:

• Direct liquid extraction and electrospray ionization are vital for rapid analysis and mass spectrometry imaging.
• Scanning probe electrospray ionization (SPESI) allows for simultaneous sampling and ionization from solid materials using a capillary probe.

Purpose of the Study:

• To investigate the dynamic behavior of nanoliter liquid volumes during SPESI sampling and ionization.
• To understand the factors influencing liquid bridge formation, breakage, and subsequent ion detection.

Main Methods:

• Utilized a novel optical technique to measure capillary probe displacement.
• Investigated the dynamic formation and breakage of the liquid bridge in SPESI.
• Correlated liquid bridge dynamics with solvent properties and flow rate.

Main Results:

• Liquid bridge formation, breakage, and ion detection times correlate with solvent physical properties.
• These time intervals are also positively correlated with the liquid flow rate.
• The study provides quantitative data on the dynamics of charged nanoliter liquid volumes.

Conclusions:

• Improved understanding of liquid bridge dynamics can enhance SPESI sampling and ionization efficiencies.
• The findings offer insights into the physicochemical properties of charged nanoliter liquid volumes.
• This research contributes to the advancement of ambient sampling and ionization techniques for mass spectrometry.