Efficient solid phase microextraction of organic pollutants based on graphene oxide/chitosan aerogel

The design and synthesis of novel high-performance solid phase microextraction (SPME) coatings towards organic pollutants with diverse chemical properties is still a challenge in sample preparation. Herein, a stable chitosan cross-linked graphene oxide (GOCS) aerogel was reported as a novel coating for solid phase microextraction. The interpenetrated meso- and macropores ensured the large surface area and high accessibility of the functional groups across the aerogel, resulting in high extraction performance towards target hydrophobic pollutants. The extraction capacities of the GOCS-coated SPME fiber towards analytes (e.g. polycyclic aromatic hydrocarbons, organophosphorus pesticides, organochlorine pesticides, pyrethroids, and polychlorinated biphenyls) were about 0.5-13 times as high as those obtained by the commercial fibers (30 μm polydimethylsiloxane (PDMS), 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB)), which was attributed to the hydrophobic, π-π, halogen bond and hydrogen bond interactions between the coating and the analytes. Under the optimized extraction conditions, superior analytical performances for PAHs were achieved with a wide linearity (0.5-1000 ng L-1), high enhancement factors (311-3740), and the low limits of detection (0.03-1.28 ng L-1). Finally, the GOCS-coated SPME fiber was successfully applied to the determination of PAHs in real water samples with good recoveries (91.6%-110%).