Novel double-confined polymeric ionic liquids as sorbents for solid-phase microextraction with enhanced stability and...

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Polymeric ionic liquids (PILs) face challenges in high-ionic-strength solutions due to anion exchange.
• Direct immersion solid-phase microextraction (SPME) is limited with conventional PILs in saline samples.
• Developing stable PIL-based sorbents is crucial for advanced analytical techniques.

Purpose of the Study:

• To develop a novel, stable polymeric ionic liquid (PIL) sorbent for direct immersion SPME.
• To enhance the stability of PIL-based SPME fibers in high-ionic-strength environments.
• To apply the developed method for the analysis of organic pollutants in aqueous samples.

Main Methods:

• Co-polymerization of 1-vinyl-3-octylimidazolium p-styrenesulfonate (VOIm(+)SS(-)) to create a double-confined PIL sorbent.
• Chemical bonding of the poly(VOIm(+)-SS(-)) onto functionalized stainless steel wire via surface radical chain-transfer reaction.
• Stability assessment using elemental analysis of sulfur and comparison with a non-sulfonated analogue (poly(VOIm(+)BS(-))).
• Gas chromatography (GC) coupled with direct immersion SPME for the extraction and determination of anilines, phenols, and phthalate esters.

Main Results:

• The novel poly(VOIm(+)-SS(-)) sorbent demonstrated superior stability in high-ionic-strength solutions compared to poly(VOIm(+)BS(-)).
• The developed direct immersion SPME-GC method exhibited good linearity, low detection limits, and acceptable repeatability for target analytes.
• Successful determination of model phthalate esters in bottled mineral water was achieved, indicating practical applicability.

Conclusions:

• The double-confined poly(VOIm(+)-SS(-)) PIL sorbent provides enhanced stability for direct immersion SPME in high-salt matrices.
• This advancement overcomes previous limitations, enabling robust analysis of pollutants in challenging aqueous samples.
• The developed SPME-GC method is a viable and effective tool for environmental monitoring and sample analysis.