Experimental verification of a model describing solid phase microextraction (SPME) of freely dissolved organic pollutants in sediment porewater.
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.
Yang
Ze-Yu
ZY
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.
Maruya
Keith A
KA
Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
Greenstein
Darrin
D
Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
Tsukada
David
D
Southern California Coastal Water Research Project, 3535 Harbor Blvd. Suite 110, Costa Mesa, CA 926267, USA.
Zeng
Eddy Y
EY
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: eddyzeng@gig.ac.cn.
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
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