High ohmic resistor hyphenated gel loading tip nano-electrospray ionization source for mini mass spectrometer

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Biochemistry

Background:

• Mini mass spectrometers require efficient and user-friendly ionization sources for field deployment.
• Nano-electrospray (nESI) is a versatile ionization technique used across various scientific disciplines.
• Corona discharge at the nESI emitter tip under aqueous conditions often leads to reduced ion intensity.

Purpose of the Study:

• To develop and evaluate a novel, low-cost, and disposable nano-electrospray ionization source for mini mass spectrometers.
• To overcome limitations of conventional nESI, such as corona discharge and the need for sample pretreatment.
• To demonstrate the applicability of the new source for analyzing biomolecules in aqueous solutions.

Main Methods:

• Coupling a high ohmic resistor-integrated gel loading tip nESI source with a custom-built mini mass spectrometer.
• Utilizing a 10 GΩ resistor to quench corona discharge at the nESI emitter tip.
• Analyzing various peptides and small molecules in aqueous solutions using the developed system.

Main Results:

• The gel loading tip nESI source demonstrated performance comparable to traditional pulled glass capillaries.
• The integrated resistor effectively quenched corona discharge, enhancing ion intensity.
• The system successfully analyzed diverse peptides and small molecules, confirming its compatibility with aqueous biomolecules.
• Direct analysis of biological samples without pretreatment was facilitated.

Conclusions:

• The developed gel loading tip nESI source is a simple, disposable, and cost-effective solution for mini mass spectrometry.
• This innovative ionization source enhances the practicality of field analysis for aqueous samples, including biomolecules.
• The resistor-assisted nESI approach mitigates common issues, paving the way for broader applications in various scientific fields.