title: Experimental verification of a model describing solid phase microextraction (SPME) of freely dissolved organic pollutants in sediment porewater.
abstract: To verify a theoretical mass balance and multiple compartment partitioning model developed to predict freely dissolved concentrations (FDCs) of hydrophobic organic chemicals (HOCs) using negligible depletion-solid phase microextraction (nd-SPME), a series of sediment slurry experiments were performed using disposable poly(dimethyl)siloxane (PDMS) coated-SPME fibers and (14)C-radiolabeled HOC analogs. First, pre-calibration of disposable PDMS coated fibers for four model compounds (phenanthrene, PCB 52, PCB 153 and p,p'-DDE) with good precision (<or=10%) was achieved. Second, sediment slurries spiked and aged with the radiolabeled analogs were extracted by SPME with manipulation of the sediment slurry mass (m(s)) or the PDMS coating volume (V(f)). The measured extent of depletion by SPME (x(e)) decreased with increasing sediment mass (m(s)); conversely, x(e) increased with increasing V(f), which is consistent with the theoretical prediction from our previous model [Yang, Z.-Y., Zeng, E.Y., Maruya, K.A., Mai, B.-X., Ran, Y., 2007b. Predicting organic contaminant concentrations in sediment porewater using solid-phase microextraction. Chemosphere 66, 1408-1414]. Moreover, the SPME-measured FDCs (C(pw,SPME)) followed the order of phenanthrene>PCB 52>PCB 153, and the measured and predicted C(pw) values were not substantially different from empirically determined values except for p,p'-DDE.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Graduate School of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ze-Yu
authors.initials: ZY
authors.lastname: Yang
authors.affiliation: Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Maruya
authors.affiliation: Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
authors.forename: Darrin
authors.initials: D
authors.lastname: Greenstein
authors.affiliation: Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
authors.forename: David
authors.initials: D
authors.lastname: Tsukada
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: eddyzeng@gig.ac.cn.
authors.forename: Eddy Y
authors.initials: EY
authors.lastname: Zeng
mesh_terms: D002138:Calibration; D003633:Dichlorodiphenyl Dichloroethylene / Q000737:chemistry / Q000302:isolation & purification; D004129:Dimethylpolysiloxanes / Q000737:chemistry / Q000302:isolation & purification; D019015:Geologic Sediments / Q000737:chemistry*; D010616:Phenanthrenes / Q000737:chemistry / Q000302:isolation & purification; D011078:Polychlorinated Biphenyls / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000379:methods* / Q000592:standards; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004129:Dimethylpolysiloxanes; D010616:Phenanthrenes; D014874:Water Pollutants, Chemical; C009407:2,5,2',5'-tetrachlorobiphenyl; C031181:phenanthrene; D003633:Dichlorodiphenyl Dichloroethylene; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl