title: Effect of condensed organic matter on solvent extraction and aqueous leaching of polycyclic aromatic hydrocarbons in soils and sediments.
abstract: The contents of nonhydrolyzable organic matter (NHC) and black carbon (BC) were measured in soils and sediments from the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons (PAHs) were extracted respectively by Soxhlet and an accelerated solvent extraction device (ASE) using different solvents. In addition, sequential aqueous leaching at different temperatures was carried out. The PAH content extracted with the sequential three solvent ASE is two times higher than that using the Soxhlet extraction method. The relationship of the PAH content with the NHC content is very significant. The PAH concentrations measured at various temperature steps fit well to the Van't Hoff equation and the enthalpy was estimated. The investigation indicates that condensed organic matter such as kerogen carbon, aged organic matter, and BC is relevant for the extraction and distribution of native PAHs in the investigated field soils and sediments.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Gunagzhou 510640, P.R. China. yran@gig.ac.cn
authors.forename: Yong
authors.initials: Y
authors.lastname: Ran
authors.forename: Ke
authors.initials: K
authors.lastname: Sun
authors.forename: Xiaoxuan
authors.initials: X
authors.lastname: Ma
authors.forename: Guohui
authors.initials: G
authors.lastname: Wang
authors.forename: Peter
authors.initials: P
authors.lastname: Grathwohl
authors.forename: Eddy Y
authors.initials: EY
authors.lastname: Zeng
mesh_terms: D002244:Carbon / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D019015:Geologic Sediments; D006812:Humic Substances; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D014050:Toluene / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D006812:Humic Substances; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D012997:Solvents; D014874:Water Pollutants, Chemical; D014050:Toluene; D002244:Carbon