Ultrathin phenyl-functionalized solid phase microextraction fiber coating developed by sol-gel deposition

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Solid-phase microextraction (SPME) is a widely used technique for sample preparation.
• Development of novel SPME fiber coatings is crucial for improving extraction efficiency and selectivity.

Purpose of the Study:

• To develop and characterize new sol-gel based SPME fibers.
• To evaluate the performance of these fibers for the extraction of non-polar compounds.

Main Methods:

• Sol-gel precursors Phenyltrimethoxysilane (PTMOS) and Methyltrimethoxysilane (MTMOS) were used.
• Optimization of precursor proportions, water content, catalyst, and reaction time.
• Characterization of film quality, thickness, microstructure, and hydrophobic properties.
• Evaluation of extraction performance for long-chain and apolar aromatic compounds compared to commercial fibers (PDMS, CW-DVB).
• Assessment of thermal and organic solvent stability.

Main Results:

• Good film quality was essential for fiber performance, with optimal thickness between 0.2-1 microm.
• Dense, non-porous microstructure and strong hydrophobic character were observed.
• Extraction efficiency for non-polar compounds was comparable to commercial PDMS and CW-DVB fibers.
• High thermal stability (350°C) and organic solvent stability were demonstrated.

Conclusions:

• The developed sol-gel SPME fibers offer a promising alternative for microextraction of non-polar compounds.
• These fibers exhibit excellent thermal and solvent stability, suitable for GC and potentially HPLC.
• Further research may be needed to address susceptibility to competition in complex matrices.