title: Influence of chemical characteristics of humic substances on the partition coefficient of a chlorinated dioxin.
abstract: The partition coefficients (Koc) of 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) with respect to a variety of humic substances (HSs) were evaluated by a method involving solid-phase microextraction and gas chromatography-electron capture detection. The log Koc values for each of the HS samples were in the range of 6.4-7.7. The log Koc values for HAs from tropical peat, brown forest and ando soils were in the range of 7.3-7.6, similar to the calculated value for the octanol-water partition coefficient (log Koc=7.56). In contrast, the log Koc values for FAs and peat HAs were 0.5-1 unit lower than the calculated value. The parameters for the polarity of HSs, as calculated from (N+O)/C, O/C atomic ratios and the carboxyl group content, were numerically similar related to the log Koc for HpCDD. These results show that the Koc values for HpCDD are significantly influenced by the polarity of HSs.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba-West, Tsukuba, Ibaraki 305-8569, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Tanaka
authors.forename: Masami
authors.initials: M
authors.lastname: Fukushima
authors.forename: Atsunori
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Hikaru
authors.initials: H
authors.lastname: Yabuta
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Tatsumi
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D002849:Chromatography, Gas; D004147:Dioxins / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D013058:Mass Spectrometry; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D004147:Dioxins; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D009584:Nitrogen; D010100:Oxygen