Improved approaches for modeling the sorption of phenanthrene by a range of plant species.
Equilibrium sorption of phenanthrene and its relationship with plant lipid contents were investigated using roots and shoots of alfalfa, ryegrass, tomato, potato, carrot, cucumber, zucchini, and pumpkin. Lipid extractions using chloroform and hexane were compared, and the influence of dechlorophyllization on lipid determinations was evaluated. The sorption isotherms were close to linear (R2 > 0.923, P < 0.05) and the plant-water partition coefficients (K(pl)) of phenanthrene obtained from the isotherms exhibited significant and positive correlations with plantlipid contents (R2 > 0.664, P < 0.05). The correlations were more significant (R2 > 0.906, P < 0.001) when dechlorophyllization was included in the lipid extraction. The measured sorption was higher than that estimated using the octanol-water partition coefficient (K(ow)) but was very close to the estimate using the triolein-water partition coefficient (K(tw)). This study leads us to conclude that dechlorophyllization is necessary for plant lipid determination and that K(tw) is more accurate as a substitute for the lipid-water partition coefficient (K(lip)) than K(ow). These novel approaches may provide substantial improvements in the application of partition-limited models for the estimation of plant uptake of organic contaminants.
Zhu
Yanhong
Y
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, State Key Laboratory of Environmental Chemistry and Ecotoxicology, P.O. Box 2871, Beijing 100085, China.
Zhang
Shuzhen
S
Zhu
Yong-Guan
YG
Christie
Peter
P
Shan
Xiaoquan
X
D000327:Adsorption; D002734:Chlorophyll / Q000737:chemistry; D018553:Cucumis sativus / Q000378:metabolism; D028464:Cucurbita / Q000378:metabolism; D019662:Cucurbitaceae / Q000378:metabolism; D018552:Daucus carota / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D006586:Hexanes / Q000378:metabolism; D008055:Lipids / Q000737:chemistry; D008129:Lolium / Q000378:metabolism; D018551:Solanum lycopersicum / Q000378:metabolism; D000455:Medicago sativa / Q000378:metabolism; D009930:Organic Chemicals; D010616:Phenanthrenes / Q000032:analysis*; D018517:Plant Roots / Q000378:metabolism; D010944:Plants / Q000737:chemistry / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis*; D011198:Solanum tuberosum / Q000378:metabolism; D014867:Water / Q000737:chemistry; D014873:Water Pollutants / Q000032:analysis
D006586:Hexanes; D008055:Lipids; D009930:Organic Chemicals; D010616:Phenanthrenes; D012989:Soil Pollutants; D014873:Water Pollutants; D014867:Water; D002734:Chlorophyll; C031181:phenanthrene