Microfluidic dual emitter electrospray ionization source for accurate mass measurements

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Microfluidics

Background:

• Sequential introduction of different solutions in mass spectrometry is challenging.
• Electrospray ionization (ESI) is a crucial technique for ionizing molecules.
• Accurate mass measurements require effective internal calibration strategies.

Purpose of the Study:

• To design and demonstrate a microfluidic device for sequential ion generation from multiple solutions.
• To achieve rapid modulation between two independent ESI emitters.
• To improve mass measurement accuracy using a reference compound for internal calibration.

Main Methods:

• Fabrication of a glass microfluidic device with two independent ESI emitters.
• Development of a voltage-switching method to modulate fluid flow and ESI potential.
• Sequential introduction of sample solutions and a reference compound.
• Mass analysis using a time-of-flight mass spectrometer.

Main Results:

• Successful design and implementation of a microfluidic device with two ESI emitters.
• Achieved rapid switching between emitters in less than 70 ms.
• Demonstrated accurate mass measurements with less than 3 ppm mass error using internal calibration.

Conclusions:

• The developed microfluidic device facilitates rapid, sequential ion generation for mass analysis.
• The system enables precise mass measurements through efficient internal calibration.
• This technology offers a promising approach for enhanced analytical performance in mass spectrometry.