title: Predicting the Relative Bioavailability of DDT and Its Metabolites in Historically Contaminated Soils Using a Tenax-Improved Physiologically Based Extraction Test (TI-PBET).
abstract: Due to their static nature, physiologically based in vitro assays often fail to provide sufficient sorption capacity for hydrophobic organic contaminants (HOCs). The addition of a sorption sink to in vitro intestinal solution has the potential to mimic dynamic intestinal uptake for HOCs, thereby increasing their desorption from soil. However, the effectiveness of sorption sinks for improving in vitro assays needs to be compared with in vivo data. In this study, Tenax was added as a sorption sink into the physiologically based extraction test (PBET), while DDT and its metabolites (DDTr) were investigated as typical HOCs. Tenax added at 0.01-0.2 g to the PBET intestinal solution sorbed ∼100% of DDTr in 6.3-19 min, indicating its ability as an effective sorption sink. DDTr bioaccessibility in six contaminated soils using Tenax-improved PBET (TI-PBET; 27-56%) was 3.4-22 fold greater than results using the PBET (1.2-15%). In vivo DDTr relative bioavailability (RBA) was measured using a mouse adipose model with values of 17.9-65.4%. The inclusion of Tenax into PBET improved the in vivo-in vitro correlation from r(2) = 0.36 (slope = 2.1 for PBET) to r(2) = 0.62 (slope = 1.2 for TI-PBET), illustrating that the inclusion of Tenax as a sorption sink improved the in vitro prediction of DDTr RBA in contaminated soils.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Sun
authors.affiliation: Future Industries Institute, University of South Australia , Mawson Lakes, South Australia 5095, Australia.
authors.forename: Albert L
authors.initials: AL
authors.lastname: Juhasz
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, China.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, China.|Soil and Water Science Department, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001315:Australia; D001682:Biological Availability; D005591:Chemical Fractionation / Q000379:methods; D002681:China; D003634:DDT / Q000302:isolation & purification / Q000378:metabolism / Q000493:pharmacokinetics*; D005260:Female; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008807:Mice, Inbred BALB C; D011108:Polymers; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification / Q000493:pharmacokinetics*
chemical_list: D011108:Polymers; D012989:Soil Pollutants; C010514:tenax; D003634:DDT