Graphene-assisted matrix solid-phase dispersion for extraction of polybrominated diphenyl ethers and their methoxylated and hydroxylated analogs from environmental samples Original Research Article

In this work, we developed a novel graphene-assisted matrix solid-phase dispersion (GA-MSPD) method for extraction of polybrominated diphenyl ethers (PBDEs) and their methoxylated (MeO–) and hydroxylated (OH–) analogs from environmental samples. We found that grinding the solid sample with chemically converted graphene (CCG) powder yielded a tight contact and sufficient dispersion of the sample matrix due to the large surface area and flexible nanosheet morphology of CCG. The resultant blend was eluted using a two-step elution strategy: PBDEs and MeO-PBDEs were eluted firstly by hexane/dichloromethane and analyzed by GC–ECD, and then OH-PBDEs were eluted by acetone and determined by LC–ESI-MS/MS. The GA-MSPD conditions were optimized in detail. Better recoveries were obtained with GA-MSPD than with other sorbents (C18 silica, Florisil and carbon nanotubes) and other extraction techniques (Soxhlet and accelerated solvent extraction). Other advantages of GA-MSPD, including reduced consumption of sorbent and solvent, good selectivity and short extraction time, were also demonstrated. In analysis of soil samples, the method detection limits of five PBDEs, ten MeO-PBDEs and ten OH-PBDEs were in the range of 5.9–28.7, 14.3–46.6, and 5.3–212.6 pg g−1 dry weight, respectively. The proposed method was successfully applied to the extraction of PBDEs, MeO-PBDEs and OH-PBDEs from different kinds of spiked environmental samples, including soil, tree bark and fish.