Surface-activated no-discharge atmospheric pressure chemical ionization

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Chemical Physics

Background:

• Atmospheric pressure chemical ionization (APCI) is a common technique for ionizing molecules.
• Existing APCI methods can be limited in ionization efficiency and sensitivity for certain analytes.
• Modifications to ionization sources are crucial for advancing analytical capabilities.

Purpose of the Study:

• To introduce and characterize a new ionization method, surface-activated chemical ionization (SACI).
• To evaluate the performance improvements offered by SACI compared to traditional no-discharge APCI.
• To optimize operating parameters for the novel SACI source.

Main Methods:

• Modification of a commercial atmospheric pressure chemical ionization (APCI) chamber by incorporating a gold surface.
• Utilizing both gas-phase and surface-activated processes for sample ionization.
• Testing the SACI source with peptide analysis and systematically varying parameters like gas flow, solution flow, pH, and surface area.

Main Results:

• SACI demonstrated significantly improved ionization efficiency compared to no-discharge APCI.
• The method effectively generates ions with high molecular mass and low charge states.
• Optimized conditions led to enhanced sensitivity and reduced spectral noise.

Conclusions:

• Surface-activated chemical ionization (SACI) represents a significant advancement in ionization techniques for mass spectrometry.
• The SACI method offers superior performance for analyzing peptides and potentially other complex molecules.
• This innovation holds promise for more sensitive and robust analytical measurements.