title: Chiral signature of α-HCH and o,p'-DDT in the soil and grass of the Central Tibetan Plateau, China.
abstract: Enantiomeric fraction (EF) of organochlorine pesticides (OCPs) has been used as a signature for tracing the source and following pathways. The chiral analysis was performed for α-HCH and o,p'-DDT in paired soil and grass samples from the Central Tibetan Plateau (CTP), a unique background region. In the case of α-HCH, excess of (-) α-HCH was predominant in 83.3% of soil samples, and 80% of grass samples showed excess of (+) enantiomer. For o,p'-DDT, 90.9% of grass samples showed excess of (-) o,p'-DDT while 50% of soil samples showed excess of the (-) enantiomer. A correlation between EFs of soil and grass was not observed for either compound. The EFs of both compounds were correlated with soil concentration and with change of sampling altitude, within EFs being lower than racemic. However, these trends were not found in grass. Our study provides a database of EFs and signatures for OCPs in the CTP, one background region of the world.
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China. Electronic address: yuangl@cugb.edu.cn.
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Yuan
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Jian-Xun
authors.initials: JX
authors.lastname: Qin
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Gen-Hou
authors.initials: GH
authors.lastname: Wang
mesh_terms: D002681:China; D003634:DDT / Q000032:analysis / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D001556:Hexachlorocyclohexane / Q000032:analysis / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis / Q000737:chemistry; D010575:Pesticides / Q000032:analysis / Q000737:chemistry*; D006109:Poaceae / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*
chemical_list: D010573:Pesticide Residues; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D003634:DDT; C016340:o,p'-DDT
keywords: Enantiomeric fraction; Grass; Organochlorine pesticides; Surface soil; Tibetan Plateau