Evaluation of a multi-fiber exchange solid-phase microextraction system and its application to on-site sampling

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Automated desorption of multiple solid-phase microextraction (SPME) fibers in gas chromatography (GC) previously required manual intervention.
• This limitation hindered the analysis of numerous on-site samples using various fiber assemblies.

Purpose of the Study:

• To critically evaluate the performance of the novel Multi-Fiber Exchange (MFX) system.
• To assess the MFX system's storage stability and long-term operational capabilities for automated SPME-GC analysis.

Main Methods:

• The MFX system was evaluated for continuous operation and precision across multiple extraction/injection cycles.
• The storage stability of different SPME fiber coatings on the MFX tray was assessed over 24 hours post-sampling.
• Analyte loss was quantified for specific volatile organic compounds (VOCs) including benzene, toluene, and xylenes.

Main Results:

• The MFX system demonstrated continuous and precise operation for multiple extraction/injection cycles.
• Carboxen/polydimethylsiloxane was the only fiber coating that maintained efficient analyte storage (≤10% loss for target VOCs) on the MFX tray for up to 24 hours.
• High-throughput analysis was confirmed through unattended desorption of multiple fibers after on-site sampling.

Conclusions:

• The Multi-Fiber Exchange system effectively automates the desorption process for multiple SPME fibers, overcoming previous limitations.
• The Carboxen/polydimethylsiloxane fiber coating is suitable for field sampling and storage up to 24 hours prior to automated analysis.
• The MFX system facilitates high-throughput environmental monitoring and on-site analysis of volatile organic compounds.