title: Isotopic exchange on solid-phase micro extraction fiber in sediment under stagnant conditions: Implications for field application of performance reference compound calibration.
abstract: An overlooked issue for field application of in situ performance reference compound (PRC) calibration methods is the validity of the assumption that both the sorption of a target compound and desorption of its corresponding PRC follow the first-order kinetics with the same rate constants under stagnant conditions. In the present study, disposable polydimethylsiloxane fibers of 2 sizes (7 and 35 µm) impregnated with 8 (13) C-labeled or deuterated PRCs were statically deployed into different marine sediments, from which the kinetics for sorption of the target compounds and desorption of the PRCs were characterized. Nonsymmetrical profiles were observed for exchange of the target analytes and their corresponding PRCs in sediment under stagnant conditions. The hysteretic desorption of PRCs in the kinetic regime may be ascribed to the low chemical potential between the fiber and sediment porewater, which reflects the inability of water molecules to rapidly diffuse through sediment to solvate the PRCs in the aqueous layer around the fiber surface. A moderate correlation (r = 0.77 and r = 0.57, p < 0.05 for both regressions) between the PRC-calibrated equilibrium concentrations of 1,1-dichloro-2,2-bis-(chlorophenyl) ethylene (p,p'-DDE) and polychlorinated biphenyl (PCB)-153 and the lipid normalized levels in worms (Neanthes arenaceodentata) was obtained in co-exposure tests under simulating field conditions, probably resulting from slightly overestimated bioavailability because of the hysteretic desorption of PRCs and toxic effects. Environ Toxicol Chem 2016;35:1978-1985. © 2015 SETAC.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.|Department of Environmental Science, University of California, Riverside, California, USA.
authors.forename: Lian-Jun
authors.initials: LJ
authors.lastname: Bao
authors.affiliation: Department of Environmental Science, University of California, Riverside, California, USA.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Environmental Science, University of California, Riverside, California, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.|School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China.
authors.forename: Eddy Y
authors.initials: EY
authors.lastname: Zeng
authors.affiliation: Department of Environmental Science, University of California, Riverside, California, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Gan
mesh_terms: D000818:Animals; D002138:Calibration; D002247:Carbon Isotopes; D003903:Deuterium / Q000737:chemistry; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D011077:Polychaeta / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D052616:Solid Phase Extraction; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D004129:Dimethylpolysiloxanes; D014874:Water Pollutants, Chemical; D014867:Water; D003633:Dichlorodiphenyl Dichloroethylene; C013830:baysilon; D003903:Deuterium; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl
keywords: Hydrophobic organic compounds; Nonsymmetrical relationship; Passive sampling; Performance reference compound calibration; Stagnant sediment