title: [Evaluation of bioavailability of hexachlorobenzene and pentachlorobenzene to rice roots in soils by accelerated solvent extraction].
abstract: A pot experiment was conducted in greenhouse in two types of soils, Hydragric Acrisols (Ac) and Gleyi-Stagnic Anthrosols (An). Three treatments as control and the additions of 1% and 2% organic fertilizer were designed in each type of soil. The objective of this study was to evaluate the accumulation abilities of hexachlorobenzene (HCB) and its predominant metabolite of pentachlorobenzene (PeCB) by rice roots, and to compare the correlation between HCB or PeCB concentrations in rice roots and in soils extracted by four extraction solvents (hexane/acetone = 3/1(V/V), ethanol, hexane, water) to evaluate the bioavailability of HCB and PeCB to rice roots. The results showed that the mean concentrations of HCB in rice roots for Ac and An were 364.1 and 306.0 ng/g, respectively, while PeCB were 12.7 and 28.7 ng/g, respectively, which was due to the higher degradation rates of HCB in An than in Ac. Both the applications of 1% and 2% organic fertilizer inhibited HCB degradation, so as to decrease PeCB concentrations in rice roots either in Ac or An. The orders of correlation coefficient of both HCB and PeCB concentrations in rice roots and in soils extracted by four extraction solvents were ethanol > hexane/acetone > hexane > water, which indicated that ethanol was the best extraction solvent of soils to evaluate the bioavailability of HCB and PeCB to rice roots. Only the HCB concentrations in soils extracted by ethanol were significantly positive correlated with the HCB concentrations in rice roots. And the PeCB concentrations in soils extracted by all solvents except for water were significantly positive correlated with the PeCB concentrations in rice roots. Our results suggested that it was feasible to evaluate the bioavailability of HCB and PeCB to rice roots using accelerated solvent extraction by choosing proper extraction solvent.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. cyliu@issas.ac.cn
authors.forename: Cui-ying
authors.initials: CY
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
authors.forename: Xing-lun
authors.initials: XL
authors.lastname: Yang
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
mesh_terms: D001682:Biological Availability; D002722:Chlorobenzenes / Q000378:metabolism / Q000493:pharmacokinetics*; D004784:Environmental Monitoring; D005659:Fungicides, Industrial / Q000493:pharmacokinetics; D006581:Hexachlorobenzene / Q000378:metabolism / Q000493:pharmacokinetics*; D007306:Insecticides / Q000378:metabolism / Q000493:pharmacokinetics; D012275:Oryza / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism / Q000493:pharmacokinetics*; D012997:Solvents
chemical_list: D002722:Chlorobenzenes; D005659:Fungicides, Industrial; D007306:Insecticides; D012989:Soil Pollutants; D012997:Solvents; D006581:Hexachlorobenzene; C003060:pentachlorobenzene