ZIF-8/nitrogen-doped reduced graphene oxide as thin film microextraction adsorbents for simultaneous determination of novel halogenated flame retardants in crayfish-aquaculture water systems.

Novel halogenated flame retardants (HFRs) have attracted much attention due to their environmental hazard and adverse effects on human health. In this study, a sensitive and simultaneous method for the determination of six novel HFRs was developed, including tetrabromobisphenol A (TBBPA), tetrachlorobisphenolA, TBBPA bis(2-hydroxyethyl ether), TBBPA bis(allyl ether), TBBPA bis(2,3-dibromopropyl ether) and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine. ZIF-8 modified nitrogen-doped reduced graphene oxide (ZIF-8@N-rGO) was synthesized and coated onto a syringe filter to prepare a thin film microextraction (TFME) device. The adsorption capacities of ZIF-8@N-rGO for novel HFRs ranged from 50.98 to 112.84 mg g, exhibiting good extraction efficiency through a combination of π-π, hydrophobic, and hydrogen bonding interactions. The TFME device was coupled to a high-performance liquid chromatography-ultraviolet detection system to simultaneously determine target HFRs in crayfish-aquaculture water systems. Under the optimal extraction parameters, the linearities ranged from 0.1 to 100 ng mL. The method detection limits ranged from 0.030 to 0.14 ng mL and relative recoveries ranged from 88.6 to 106.2%. We found that novel HFRs were detected in water and crayfish samples and were primarily distributed in the viscera and head shell of the crayfish. The bioconcentration factors ranged from 0.25 to 19.20 L kg, indicating non-bioaccumulation in the crayfish. This study provides valuable technology and information for potential health risks of exposure to novel HFRs from consuming crayfish.