Liquid Sampling-Atmospheric Pressure Glow Discharge Ionization as a Technique for the Characterization of...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Environmental Science

Background:

• Traditional mass spectrometry ionization methods struggle with organic species in high-salt environments.
• Analyzing marine organic matter often requires challenging desalting procedures.

Purpose of the Study:

• To evaluate the effectiveness of a novel liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for analyzing organic samples in high-salt conditions.
• To compare LS-APGD performance against traditional electrospray ionization (ESI) for marine-relevant samples.

Main Methods:

• LS-APGD ionization was applied to a triglyceride mixture and dissolved organic matter in both neat and saline conditions.
• Performance was compared to electrospray ionization (ESI) under identical conditions.
• Optimized LS-APGD settings (0.25 mm electrode spacing, 20 mA) were determined.

Main Results:

• LS-APGD demonstrated equal or greater ion intensities (15%+) compared to ESI for both salt-containing and neat samples.
• LS-APGD observed a higher diversity of molecules than ESI, particularly under optimized settings.
• Adduct formation differences in high-salt conditions were noted as key to observed molecular species.

Conclusions:

• LS-APGD is a promising ionization technique for analyzing organic species in high-salt environments, including marine samples.
• The method offers potential for field applications by eliminating the need for desalting procedures.
• LS-APGD's ability to analyze low-concentration species without desalting enhances its utility in environmental studies.