Determination of water pollutants by direct-immersion solid-phase microextraction using polymeric ionic liquid...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Water quality monitoring requires sensitive detection of diverse pollutants.
• Traditional solid-phase microextraction (SPME) coatings have limitations in efficiency and analyte range.
• Polymeric ionic liquids (PILs) offer unique properties for advanced analytical applications.

Purpose of the Study:

• To develop and evaluate a novel polymeric ionic liquid (PIL) coating for direct-immersion SPME.
• To determine eighteen water pollutants, including polycyclic aromatic hydrocarbons (PAHs) and substituted phenols.
• To compare the performance of the PIL coating against commercial SPME materials.

Main Methods:

• Direct-immersion solid-phase microextraction (SPME) utilizing a novel PIL coating: poly(1-vinyl-3-hexadecylimidazolium) bis[(trifluoromethyl)sulfonyl]imide.
• Gas chromatography-mass spectrometry (GC-MS) for pollutant identification and quantification.
• Comparative analysis with commercial SPME coatings (PDMS and PA) and normalization of coating thickness.

Main Results:

• The PIL fiber coating achieved average relative recoveries of 92.5% (deionized water) and 90.8% (well water) at a spiked level of 5 ng mL(-1).
• Detection limits ranged from 0.005 ng mL(-1) (fluoranthene) to 4.4 ng mL(-1) (4-chloro-3-methylphenol) with a 60-min extraction time.
• The PIL coating demonstrated superior extraction efficiency compared to PDMS coatings for all analytes and was effective for nonpolar compounds.

Conclusions:

• The developed IL-SPME-GC-MS method with a novel PIL coating is highly effective for determining a wide range of water pollutants.
• The PIL coating offers significant advantages over conventional SPME materials, particularly for nonpolar analytes.
• This advanced SPME technique provides a sensitive and efficient approach for environmental water analysis.