Subatmospheric electrospray interface for coupling of microcolumn separations with mass spectrometry

Area of Science:

• Analytical Chemistry
• Separation Science
• Mass Spectrometry

Background:

• Coupling microcolumn separation techniques with mass spectrometry (MS) is crucial for sensitive analysis.
• Existing interfaces can face challenges with pressure drops and fluid delivery, limiting their applicability.

Purpose of the Study:

• To develop a modular subatmospheric electrospray interface for seamless coupling of microcolumn separations and MS.
• To achieve stable electrospray generation without external pumps and accommodate various capillary types.

Main Methods:

• A liquid junction with a removable microelectrospray tip was designed, enclosed in a subatmospheric chamber.
• The interface maintained atmospheric pressure at the column inlet, preventing pressure drops.
• Fiber optic UV detection was integrated near the electrospray tip for monitoring and troubleshooting.

Main Results:

• A continuous and stable electrospray was achieved without external pumps.
• The interface effectively coupled capillary electrophoresis and capillary liquid chromatography, supporting columns with high theoretical plate counts.
• Peptide samples at submicromolar concentrations were detected, achieving attomole limits of detection.

Conclusions:

• The developed subatmospheric electrospray interface enhances the coupling of microseparation techniques with mass spectrometry.
• It offers a versatile and sensitive platform for analyzing peptides and other analytes.
• The interface demonstrates robustness and minimal impact on separation quality.