Development of a dual-electrospray ionization source with in-line absorbance-based voltage control

Area of Science:

• Analytical Chemistry
• Mass Spectrometry

Background:

• Emitter tip arrays in electrospray ionization (ESI) are crucial for mass spectrometry (MS) sample introduction.
• Current methods often require manual control of high voltage for optimal analyte signal and reduced background noise.

Purpose of the Study:

• To develop an automated system for applying electrospray voltage only when analytes are present in the sample stream.
• To enhance the efficiency and accuracy of ESI-MS by minimizing background signals and maximizing analyte detection.

Main Methods:

• An in-line absorbance detector was integrated to monitor the fluidic path for analyte presence.
• A Raspberry Pi-controlled system was employed to dynamically apply high voltage to the ESI emitter tip.
• A delay volume was incorporated between the detector and the emitter to synchronize voltage application with analyte elution.

Main Results:

• Demonstrated successful automated, pulsed voltage application to two parallel sample channels.
• Showcased the ability to maximize analyte signal during simultaneous elution events.
• Validated the technique for targeted ESI-MS sample introduction.

Conclusions:

• The developed automated system effectively controls electrospray voltage based on real-time analyte detection.
• This approach offers improved analyte signal-to-noise ratio and simplifies ESI-MS operation.
• The automated ESI voltage control is beneficial for complex sample matrices and parallel analyses.