A monolith graphene oxide and mesoporous carbon composite sorbent in polyvinyl alcohol cryogel to extract and enrich fluoroquinolones in honey

A porous monolith composite sorbent of graphene oxide (GO) and mesoporous carbon (MPC) in polyvinyl alcohol (PVA) cryogel was developed and employed for the solid phase extraction and enrichment of fluoroquinolones. Due to the porosity of the cryogel, the backpressure created by the sample flow was low, which helped stabilize the entrapped GO and MPC. The four target fluoroquinolones could then be adsorbed efficiently, repeatedly and simultaneously by hydrogen bonding, and hydrophobic and π-π interactions. The extracted fluoroquinolones were determined by high-performance liquid chromatography (HPLC). The developed method provided limits of detection ranging from 0.15 to 3.0 μg L−1 and limits of quantification ranging from 0.5 to 10.0 μg L−1. The developed sorbent successfully extracted trace fluoroquinolones in honey, achieving extraction recoveries in the range of 88.9–99.4 %, and good precision with RSDs between 0.7 % and 5.1 %. The advantages of the proposed porous monolith composite sorbent are its high extraction efficiency, simple and rapid procedure, good precision, good stability and reusability that enabled 10 extraction-regeneration cycles from a single sorbent.