Determining equilibrium partition coefficients between lipid/protein and polydimethylsiloxane for highly hydrophobic organic contaminants using preloaded disks

摘要: Bioaccumulation of hydrophobic organic contaminants is great concern and understanding their partitioning to biological phases crucial for estimating bioaccumulation potential. The estimation, however, was large uncertainty highly (HHOCs) with log KOW>9 due the challenge quantifying water concentrations. In present study, partition coefficients between polydimethylsiloxane (PDMS) storage lipid (KSL,PDMS), membrane (KML,PDMS) protein (Kpro,PDMS) were measured 21 polychlorinated biphenyls (PCBs), 14 polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP) decabromodiphenyl ethane (DBDPE), covering KOW from 5.07 11.6, using a preloaded PDMS depletion method. values KSL,PDMS, KML,PDMS Kpro,PDMS in ranges 5.36-52.5, 0.286-11.8 0.067-2.62g/g, respectively, being relatively constant although extend more than six orders magnitude. relative sorption capacity showed dominant phase biota, followed by lowest. KPDMS,pro compounds KOW<9 similar (0.382-14.9g/g) regardless thickness disks (58-209μm). For HHOCs, dropped when thinner used, as result slow diffusion HHOCs PDMS. 58-μm ranged 1.78 6.85g/g, which consistent KOW<9. This validated that independent chemical hydrophobicity, showing advantage PDMS-based methods directly estimate potential HHOCs.