title: Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin.
abstract: In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from -29.0‰ to -26.5‰ in soil spiked with 2mg/kg lambda-cyhalothrin, and to -27.5‰ with 10mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as -2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies.
authors.affiliation: MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Environmental Engineering, Quzhou University, Quzhou 324000, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Shen
authors.affiliation: MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Zemin
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xichang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Effect-Directed Analysis, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany. Electronic address: fxyang@zju.edu.cn.
authors.forename: Fangxing
authors.initials: F
authors.lastname: Yang
mesh_terms: D001673:Biodegradation, Environmental; D002247:Carbon Isotopes; D005591:Chemical Fractionation; D009570:Nitriles / Q000032:analysis / Q000378:metabolism*; D011722:Pyrethrins / Q000032:analysis / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D009570:Nitriles; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C037304:cyhalothrin
keywords: Biodegradation; Carbon isotope fractionation; Compound-specific stable isotope analysis; Lambda-cyhalothrin; Soil