Pulsed dual electrospray ionization for ion/ion reactions

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Physical Chemistry

Background:

• Ion/ion reactions are crucial for studying gas-phase ion chemistry.
• Generating ions of opposite polarities simultaneously or sequentially is challenging.
• Existing methods often require complex instrumentation or modifications.

Purpose of the Study:

• To develop a versatile pulsed dual electrospray ionization source.
• To enable efficient generation of positive and negative ions for ion/ion reactions.
• To demonstrate the source's capability in various gas-phase ion chemistry applications.

Main Methods:

• Utilized a pulsed dual electrospray ionization source with two emitters (nano-ESI and ESI).
• Alternately pulsed sprayer potentials to generate ions of opposite polarity sequentially.
• Employed a triple quadrupole/linear ion trap tandem mass spectrometer (Sciex Q TRAP) for ion trapping and reaction.
• Sequentially injected ions into a linear ion trap for axial trapping using auxiliary radio frequency voltage.

Main Results:

• Successfully generated positive and negative ions separately in time for ion/ion reactions.
• Demonstrated applications including charge reduction of multiply charged protein ions.
• Showcased charge inversion of peptide ions and protein-protein complex formation.
• The source is adaptable to existing spray interfaces with minimal modifications.

Conclusions:

• The pulsed dual electrospray ionization source is a powerful tool for gas-phase ion/ion chemistry.
• It offers flexibility and ease of use for studying complex ion interactions.
• This technology advances the investigation of biomolecular ions and their reactions.