Automated direct-immersion solid-phase microextraction using crosslinked polymeric ionic liquid sorbent coatings for the determination of water pollutants by gas chromatography

Abstract

Four different crosslinked polymeric ionic liquid (PIL)-based sorbent coatings were evaluated in an automated direct-immersion solid-phase microextraction method (automated DI-SPME) in combination with gas chromatography (GC). The crosslinked PIL coatings were based on vinyl-alkylimidazolium- (ViCnIm-) or vinylbenzyl-alkylimidazolium- (ViBzCnIm-) IL monomers, and di-(vinylimidazolium)dodecane ((ViIm)2C12-) or di-(vinylbenzylimidazolium)dodecane ((ViBzIm)2C12-) dicationic IL crosslinkers. In addition, a PIL-based hybrid coating containing multi-walled carbon nanotubes (MWCNTs) was also studied. The studied PIL coatings were covalently attached to derivatized nitinol wires and mounted onto the Supelco assembly to ensure automation when acting as SPME coatings. Their behavior was evaluated in the determination of a group of water pollutants, after proper optimization. A comparison was carried out with three common commercial SPME fibers. It was observed that those PILs containing a benzyl group in their structures, either in the IL monomer and crosslinker (PIL-1-1) or only in the crosslinker (PIL-0-1), were the most efficient sorbents for the selected analytes. The validation of the overall automated DI-SPME-GC-flame ionization detector (FID) method gave limits of detection down to 135 μg · L(-1) for p-cresol when using the PIL-1-1 and down to 270 μg · L(-1) when using the PIL-0-1; despite their coating thickness: ~2 and ~5 μm, respectively. Average relative recoveries with waters were of 85 ± 14 % and 87 ± 15 % for PIL-1-1 and PIL-0-1, respectively. Precision values as relative standard deviation were always lower than 4.9 and 7.6 % (spiked level between 10 and 750 μg · L(-1), as intra-day precision). Graphical Abstract Automated DI-SPME-GC-FID using crosslinked-PILs sorbent coatings for the determination of waterpollutants.

Utilization of highly robust and selective crosslinked polymeric ionic liquid-based sorbent coatings in direct-immersion solid-phase microextraction and high-performance liquid chromatography for determining polar organic pollutants in waters

“…Nitinol fibers have been also used as supports with the same polymerization approach for SPME-GC [27], generating highly robust coatings. More recently, nitinol supports prepared with the UV method of polymerization have been mounted onto commercial SPME devices and used in an automated DI-SPME-GC approach [28].…”

Comparison of headspace solid‐phase microextraction and solvent extraction method for the simultaneous analysis of various soil fumigants in soil or water by gas chromatography–mass spectrometry

“…HS‐SPME was reported to be suitable for the extraction of fumigants from complex substrates such as soil, vegetables, and fruit [15, 17]. On the other hand, the DI‐SPME method was reported to be suitable for extracting some analytes that had a slightly higher solubility in water and were less volatile [36–38], such as carbamate pesticides [39], triazole fungicides [40], polar organic pollutants in waters [41,42], trihalomethanes and organochlorine pesticides [43], polycyclic aromatic hydrocarbons [44], urine, saliva, and milk [45, 46]. The reason for the higher recovery rate of the HS‐SPME method might be that the fumigants had a low water solubility and high volatility, and were more likely to exist in the gas phase.…”

High‐throughput microscale extraction using ionic liquids and derivatives: A review

“…Several IL‐ and PIL‐based sorbent coatings have been specifically designed for SPME using the fiber‐type configuration [7,10]. In one study, four different PIL‐based sorbent coatings were employed in a totally automated SPME approach [43]. All steps performed during extraction (in the direct immersion mode, DI‐SPME) and thermal desorption were carried out with the help of a CombiPAL autosampler (CTC Analytics) directly mounted on top of the separation and detection system (GC with flame ionization detection, GC–FID).…”

“…The sample throughput of the method was significantly improved due to the high thermal stability of the developed PILs that allowed thermal desorption of the analytes at 250°C in only 2 min without significant carryover. This characteristic of the methodology allowed for a more efficient and expedite methodology because extraction was performed using the software‐controlled automated system while the previous sample being analyzed in the GC‐FID system [43].…”