Exploiting the tunable selectivity features of polymeric ionic liquid-based SPME sorbents in food analysis.

In this work, the performances of polymeric ionic liquid (PIL) based solid-phase microextraction (SPME) coatings were assessed for applications concerning food safety and quality. Two different polymeric ionic liquid coatings, namely poly(1-4-vinylbenzyl-3-hexadecylimidazolium) bis[(trifluoromethyl)sulfonyl] imide (poly([VBHDIM][NTf2]), PIL 1, and N,N-didecyl-N-methyl-d-glucaminium poly(2-methyl-acrylic acid 2-[1-(3-{2-[2-(3-trifluoromethanesulfonylamino-propoxy)-ethoxy]-ethoxy}-propylamino)-vinylamino]-ethyl ester) (poly([DDMGlu][MTFSI]), PIL 2, were evaluated. The PIL-based coatings were compared to commercially available SPME coatings in terms of their performance toward extraction of pesticides and fruit metabolites.

Use of ionic liquids as headspace gas chromatography diluents for the analysis of residual solvents in pharmaceuticals.

In this study, two ionic liquids (ILs), 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([BMIM][NTf]) and trihexyltetradecylphosphonium bis[(trifluoromethyl)sulfonyl]imide ([P][NTf]) were examined as contemporary diluents for residual solvent analysis using static headspace gas chromatography (SHS-GC) coupled with flame ionization detection (FID). ILs are a class of non-molecular solvents featuring negligible vapor pressure and high thermal stabilities. Owing to these favorable properties, ILs have potential to enable superior sensitivity and reduced interference, compared to conventional organic diluents, at high headspace incubation temperatures.

Determination of acrylamide in brewed coffee and coffee powder using polymeric ionic liquid-based sorbent coatings in solid-phase microextraction coupled to gas chromatography-mass spectrometry.

This study describes a simple and rapid sampling method employing a polymeric ionic liquid (PIL) sorbent coating in direct immersion solid-phase microextraction (SPME) for the trace-level analysis of acrylamide in brewed coffee and coffee powder. The crosslinked PIL sorbent coating demonstrated superior sensitivity in the extraction of acrylamide compared to all commercially available SPME coatings. A spin coating method was developed to evenly distribute the PIL coating on the SPME support and reproducibly produce fibers with a large film thickness.

Determination of trace level genotoxic impurities in small molecule drug substances using conventional headspace gas chromatography with contemporary ionic liquid diluents and electron capture detection.

Ionic liquids (ILs) were used as a new class of diluents for the analysis of two classes of genotoxic impurities (GTIs), namely, alkyl/aryl halides and nitro-aromatics, in small molecule drug substances by headspace gas chromatography (HS-GC) coupled with electron capture detection (ECD). This novel approach using ILs as contemporary diluents greatly broadens the applicability of HS-GC for the determination of high boiling (≥ 130°C) analytes including GTIs with limits of detection (LOD) ranging from 5 to 500 parts-per-billion (ppb) of analytes in a drug substance. This represents up to tens of thousands-fold improvement compared to traditional HS-GC diluents such as dimethyl sulfoxide (DMSO) and dimethylacetamide (DMAC).

Chemical immobilization of crosslinked polymeric ionic liquids on nitinol wires produces highly robust sorbent coatings for solid-phase microextraction.

Super elastic nitinol (NiTi) wires were exploited as highly robust supports for three distinct crosslinked polymeric ionic liquid (PIL)-based coatings in solid-phase microextraction (SPME). The oxidation of NiTi wires in a boiling (30%w/w) H2O2 solution and subsequent derivatization in vinyltrimethoxysilane (VTMS) allowed for vinyl moieties to be appended to the surface of the support. UV-initiated on-fiber copolymerization of the vinyl-substituted NiTi support with monocationic ionic liquid (IL) monomers and dicationic IL crosslinkers produced a crosslinked PIL-based network that was covalently attached to the NiTi wire.

A chemometric approach toward the detection and quantification of coffee adulteration by solid-phase microextraction using polymeric ionic liquid sorbent coatings.

Solid-phase microextraction (SPME) using cross-linked polymeric ionic liquid (PIL)-based sorbent coatings was used to extract volatile aroma-related compounds from coffee samples. Several PIL-based coatings were screened alongside a commercial poly(acrylate) (PA) SPME coating. The best performing PIL-based SPME fiber, poly(1-vinyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonylimide]) with 50% (w/w) 1,12-di(3-vinylbenzylimidazolium)dodecane dibis[(trifluoromethyl)sulfonyl]imide incorporated cross-linker, was used to isolate the volatile fraction of Arabica coffee.

Polymeric ionic liquid coatings versus commercial solid-phase microextraction coatings for the determination of volatile compounds in cheeses.

The extraction performance of four polymeric ionic liquid (PIL)-based solid-phase microextraction (SPME) coatings has been studied and compared to that of commercial SPME coatings for the extraction of 16 volatile compounds in cheeses. The analytes include 2 free fatty acids, 2 aldehydes, 2 ketones and 10 phenols and were determined by headspace (HS)-SPME coupled to gas chromatography (GC) with flame-ionization detection (FID). The PIL-based coatings produced by UV co-polymerization were more efficient than PIL-based coatings produced by thermal AIBN polymerization.

Determination of polychlorinated biphenyls in ocean water and bovine milk using crosslinked polymeric ionic liquid sorbent coatings by solid-phase microextraction.

Crosslinked polymeric ionic liquid (PIL)-based sorbent coatings were employed in the extraction of 21 polychlorinated biphenyls (PCBs) from ocean water and bovine milk using solid-phase microextraction (SPME). The extraction temperature, time, and concentration of sodium chloride added to the matrix were optimized in order to determine the best extraction conditions for the extraction of PCBs. The analytical performance of the crosslinked PIL-based SPME fibers was compared with a commercial 7 µm polydimethylsiloxane (PDMS) fiber using gas chromatography (GC) employing an electron capture detector (ECD) and mass spectrometric detection (MS).

Insight into the extraction mechanism of polymeric ionic liquid sorbent coatings in solid-phase microextraction.

An investigation into the mechanism of extraction for polymeric ionic liquid (PIL)-based solid phase microextraction sorbent coatings is described. Four PIL-based coatings, namely, a poly(1-4-vinylbenzyl)-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl] imide (poly([VBHDIM][NTf2])) PIL produced through 2,2'-azo-bis(isobutyronitrile) (AIBN) initiated free-radical polymerization, a UV-initiated poly(1-vinyl-3-hexylimidazolium) chloride (poly([VHIM][Cl])) PIL, and two crosslinked PILs containing the same IL monomers copolymerized with dicationic IL crosslinkers, were investigated. Calibration curves of 1-octanol were plotted in the presence of naphthalene, a model interfering compound, to observe changes in the linear range, sensitivity, and amount of analytes extracted.

Ultraviolet photoinitiated on-fiber copolymerization of ionic liquid sorbent coatings for headspace and direct immersion solid-phase microextraction.

A high-throughput method for the production of solid-phase microextraction (SPME) sorbent coatings via ultraviolet (UV) photoinitiated copolymerization of ionic liquid (IL) monomers on a fused silica support is described. The copolymerization of monocationic and dicationic IL cross-linkers was performed "on-fiber" using UV initiated free radical polymerization. Mixtures composed of various amounts of the IL cross-linker, UV initiator (DAROCUR 1173), and IL monomer were dip-coated onto an etched and derivatized fused silica support and placed in a high-capacity UV reactor.

Selective extraction of genotoxic impurities and structurally alerting compounds using polymeric ionic liquid sorbent coatings in solid-phase microextraction: Alkyl halides and aromatics.

A series of polymeric ionic liquids (PILs) possessing varied chemical makeup and composition were applied as selective solid-phase microextraction (SPME) sorbent coatings for the analysis of genotoxic impurities (GTIs) and related structurally alerting compounds, namely, alkyl halides and aromatics. In addition to exploiting two previously synthesized PILs as selective coatings, two new PILs, namely, N,N-didecyl-N-methyl-D-glucaminium poly(2-methyl-acrylic acid 2-[1-(3-{2-[2-(3-trifluoromethanesulfonylamino-propoxy)-ethoxy]-ethoxy}-propylamino)-vinylamino]-ethyl ester) (poly([DDMGlu][MTFSI])), and poly(1-vinyl-3-propylphenylimidazolium) chloride (poly([VPPIM][Cl])), were designed, synthesized, and their selectivity examined in the extraction of the selected analytes. The glucaminium-based coating was developed to exploit the hydrogen bond-acidic hydroxyl groups within the carbohydrate moiety of the PIL in addition to dispersive capabilities resulting from the cation and anion.

Ionic liquids in solid-phase microextraction: a review.

Solid-phase microextraction (SPME) has undergone a surge in popularity within the field of analytical chemistry in the past two decades since its introduction. Owing to its nature of extraction, SPME has become widely known as a quick and cost-effective sample preparation technique. Although SPME has demonstrated extraordinary versatility in sampling capabilities, the technique continues to experience a tremendous growth in innovation.