Electrochemical preparation of poly(3-methylthiophene-carbazole)/graphene oxide composite coating for the highly effective solid-phase microextraction of some fragrance

Determination of Volatile Water Pollutants Using Cross-Linked Polymeric Ionic Liquid as Solid Phase Micro-Extraction Coatings

Ionic liquids found a wide application in catalysis and extraction due to their unique properties. Herein, ethylene glycol dimethacrylate as the cross-linker and 1-vinyl-3- butylimidazolium tetrafluoroborate as functional monomer via thermally initiated free-radical polymerization was prepared as a novel copolymer solid phase micro-extraction (SPME) coating. A surface modified stainless-steel wire was implemented as the substrate. Factors affecting the extraction performances of the copolymer, including the molar ratio of monomers to cross-linkers, the amount of porogen agent, and polymerization time were evaluated and optimized. To evaluate the extraction performance, five commonly seen polycyclic aromatic hydrocarbons (PAHs) were taken as the analytical targets. The potential factors affecting extraction efficiency were optimized. The as-prepared SPME device, coupled with gas chromatography, was successfully applied for the determination of PAHs in water samples. The wide linear range, low detection limit, good reproducibility, selectivity, and excellent thermal stability indicate the promising application of the newly developed SPME fiber in environmental monitoring as well as in other samples having complex matrices.

Microextraction of polycyclic aromatic hydrocarbons by using a stainless steel fiber coated with nanoparticles made from a porous aromatic framework

A porous aromatic framework of type PAF-6 was synthesized and explored as a coating onto a steel wire for using in solid-phase microextraction of polycyclic aromatic hydrocarbons (PAHs), phthalate plasticizers, and n-alkanes. The extraction temperature, extraction time, salt concentration, agitation speed, desorption temperature, and desorption time were optimized. This method for SPME resulted in the enrichment factors ranging from 122 to 1090 for PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene), from 122 to 271 for plasticizers (diisobutyl phthalate, dibutyl phthalate, benzyl butyl phthalate, dicyclohexyl phthalate), and from 9 to 113 for n-alkanes (n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-octadecane and n-eicosane). The good extraction of the PAHs is assumed to be due to their π-stacking interaction and hydrophobic effect. The PAF-6 coated fibers are durable and can be reused more than 100 times without significant loss of extraction performance. In combination with GC-MS detection, the method has limits of detection in the range from 0.8 to 4.2 ng L^-1 in case of PAHs. The relative standard deviations for five replicate determinations of the PAHs by using one fiber are in the range from 5.2 to 8.5%. When using different fibers, they range from 7.1 to 9.6%. The recoveries of PAHs from water samples at a spiking level of 20 ng L^-1 are in the range from 89.5 to 103.1%, with relative standard deviations ranging from 4.0 to 9.3%. Graphical abstract A porous aromatic framework of type PAF-6 was synthesized and used as a novel coating for the solid-phase microextraction of polycyclic aromatic hydrocarbons prior to their determination by gas chromatography with mass spectrometric detection.