Subambient pressure ionization with nanoelectrospray source and interface for improved sensitivity in mass...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Separation Science

Background:

• Conventional atmospheric pressure electrospray ionization mass spectrometry (ESI-MS) sources face limitations in ion transmission efficiency due to conductance-limiting inlets.
• Reversed-phase liquid chromatography (RPLC) separations often require specific solvent compatibility for effective interfacing with mass spectrometers.

Purpose of the Study:

• To design and evaluate a novel nanoelectrospray ionization mass spectrometry (ESI-MS) source and interface operating at subambient pressure.
• To improve ion production, transmission, and desolvation efficiency for enhanced mass spectrometry sensitivity.

Main Methods:

• Development of a subambient pressure ionization with nanoelectrospray (SPIN) source where the electrospray emitter is positioned within an electrodynamic ion funnel inside the mass spectrometer.
• Evaluation of the SPIN source performance by comparing sensitivity and ion transmission with a standard atmospheric pressure ESI source using RPLC-compatible solvents.
• Investigation of desolvation efficiency at various flow rates.

Main Results:

• The SPIN source demonstrated an approximately 5-fold improvement in sensitivity compared to a standard atmospheric pressure ESI source.
• The design avoids conductance-limiting inlets, enabling more efficient ion transmission to the mass analyzer.
• The integrated ion funnel effectively facilitated desolvation, aiding gas-phase analyte ion formation.

Conclusions:

• The developed SPIN source offers a significant advancement in ESI-MS technology, improving sensitivity and enabling new interface designs.
• This subambient pressure approach is compatible with RPLC solvents and enhances the efficiency of ion generation and transfer.
• The findings highlight the potential of the SPIN source for more sensitive and efficient mass spectrometry analyses.