Highly porous solid-phase microextraction fiber coating based on poly(ethylene glycol)-modified ormosils synthesized...

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Solid-phase microextraction (SPME) is a widely used technique for sample preparation.
• Conventional SPME fibers often have limitations in terms of extraction speed and efficiency.

Purpose of the Study:

• To develop and characterize novel SPME fibers coated with Carbowax 20M-modified silica using a sol-gel process.
• To compare the performance of these new fibers against commercial SPME fibers.

Main Methods:

• Fused silica fibers were coated using a sol-gel process with Carbowax 20M-modified silica.
• Scanning electron microscopy (SEM) was used to analyze the coating morphology and thickness.
• Headspace extraction of test analytes (benzene, o-xylene) was performed.
• Comparison with commercial polydimethylsiloxane (PDMS) and Carbowax-divinylbenzene (DVB) fibers.

Main Results:

• The sol-gel coating exhibited a highly porous, sponge-like structure with an average thickness of 8 ± 1 microm.
• Significantly shorter equilibrium times were observed, ranging from <3 min for benzene to 15 min for o-xylene.
• Extraction efficiencies were superior, with the sol-gel Carbowax fiber achieving 230% and 540% of the extracted mass for o-xylene compared to PDMS and Carbowax-DVB fibers, respectively.

Conclusions:

• The sol-gel Carbowax SPME fibers demonstrate enhanced performance characteristics.
• These novel fibers offer a promising alternative for efficient and rapid extraction of volatile organic compounds.