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Bioaccumulation Factor

The Experts below are selected from a list of 5547 Experts worldwide ranked by ideXlab platform

Baoyuan Guo – 1st expert on this subject based on the ideXlab platform

  • stereoselectivity in Bioaccumulation and excretion of epoxiconazole by mealworm beetle tenebrio molitor larvae
    Ecotoxicology and Environmental Safety, 2014
    Co-Authors: Xiaotian Lv, Chen Liu, Yaobin Li, Yong Xin Gao, Huili Wang, Jianzhong Li, Baoyuan Guo

    Abstract:

    Stereoselectivity in Bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20 mg/kg and 2 mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective Bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20 mg/kg dose. The stereoselectivity in Bioaccumulation in the 2 mg/kg dosage was not obvious compared to the 20 mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by Bioaccumulation Factor (BAF). (C) 2014 Elsevier Inc. All rights reserved.

  • Bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure.
    Chirality, 2013
    Co-Authors: Xiaotian Lv, Baoyuan Guo, Chen Liu, Yaobin Li, Yong Xin Gao, Huili Wang, Jianzhong Li

    Abstract:

    The Bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure under laboratory conditions were investigated using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. The wheat bran fed to Tenebrio molitor larvae was spiked with racemic myclobutanil at two dose levels of 20 mg/kg and 2 mg/kg (dry weight). The results showed that there was a significant trend of enantioselective Bioaccumulation in the larvae with a preferential accumulation of (−)-myclobutanil in 20 mg/kg dose exposure, but it was not obviously observed in the 2 mg/kg dose group. A kinetic model considering enantiomerization between the two enantiomers based on first-order reactions was built and the rate constants were estimated to discuss the kinetic reason for the different concentrations of individual enantiomers in the larvae. The approximations implied an inversion between the two enantiomers with a relatively higher rate of the inversion from (−)-myclobutanil to (+)-myclobutanil. Meanwhile, analysis of data of excretion samples suggested the active excretion is probably an important pathway for the insect to eliminate myclobutanil rapidly with nonenantioselectivity as a passive transport process, which was consistent with the low accumulation efficiency of myclobutanil measured by BAF (Bioaccumulation Factor). Chirality 25:890–896, 2013. © 2013 Wiley Periodicals, Inc.

Jon A Arnot – 2nd expert on this subject based on the ideXlab platform

  • use of the Bioaccumulation Factor to screen chemicals for Bioaccumulation potential
    Environmental Toxicology and Chemistry, 2012
    Co-Authors: Jed Costanza, David G Lynch, Robert S Boethling, Jon A Arnot

    Abstract:

    The fish bioconcentration Factor (BCF), as calculated from controlled laboratory tests, is commonly used in chemical management programs to screen chemicals for Bioaccumulation potential. The Bioaccumulation Factor (BAF), as calculated from field-caught fish, is more ecologically relevant because it accounts for dietary, respiratory, and dermal exposures. The BCFBAF™ program in the U.S. Environmental Protection Agency’s Estimation Programs Interface Suite (EPI Suite™ Ver 4.10) screening-level tool includes the Arnot-Gobas quantitative structure-activity relationship model to estimate BAFs for organic chemicals in fish. Bioaccumulation Factors can be greater than BCFs, suggesting that using the BAF rather than the BCF for screening Bioaccumulation potential could have regulatory and resource implications for chemical assessment programs. To evaluate these potential implications, BCFBAF was used to calculate BAFs and BCFs for 6,034 U.S. high- and medium-production volume chemicals. The results indicate no change in the Bioaccumulation rating for 86% of these chemicals, with 3% receiving lower and 11% receiving higher Bioaccumulation ratings when using the BAF rather than the BCF. All chemicals that received higher Bioaccumulation ratings had log K(OW ) values greater than 4.02, in which a chemical’s BAF was more representative of field-based Bioaccumulation than its BCF. Similar results were obtained for 374 new chemicals. Screening based on BAFs provides ecologically relevant results without a substantial increase in resources needed for assessments or the number of chemicals screened as being of concern for Bioaccumulation potential.

  • a review of bioconcentration Factor bcf and Bioaccumulation Factor baf assessments for organic chemicals in aquatic organisms
    Environmental Reviews, 2006
    Co-Authors: Jon A Arnot

    Abstract:

    Bioaccumulation assessment is important in the scientific evaluation of risks that chemicals may pose to humans and the environment and is a current focus of regulatory effort. The status of Bioaccumulation evaluations for organic chemicals in aquatic systems is reviewed to reduce uncertainty in Bioaccumulation measurement, to provide quality data for assessment, and to assist in model development. A review of 392 scientific literature and database sources includes 5317 bioconcentration Factor (BCF) and 1656 Bioaccumulation Factor (BAF) values measured for 842 organic chemicals in 219 aquatic species. A data quality assessment finds that 45% of BCF values are subject to at least one major source of uncertainty and that measurement errors generally result in an underestimation of actual BCF values. A case study of organic chemicals on the Canadian Domestic Substances List indicates that empirical data are available for less than 4% of the chemicals that require evaluation and of these chemicals, 76% have less than three acceptable quality BCF or BAF values. Field BAFs tend to be greater than laboratory BCFs emphasizing the importance of environmental measurement for reliable assessment; however, only 0.2% of current use organic chemicals have BAF measurements. Key parameters influencing uncertainty and variability in BCF and BAF data are discussed using reviewed data and models. A critical evaluation of representative BCF and BAF models in relation to existing measurements and regulatory criteria in Canada indicate the probability of Type II errors, i.e., false negatives or “misses”, using BCF models for Bioaccumulation assessment may be as high as 70.6% depending on the model. Recommendations for the selection of measured and modelled values used in Bioaccumulation assessment are provided, and improvements for the science and regulatory criteria are proposed.

Xiaotian Lv – 3rd expert on this subject based on the ideXlab platform

  • stereoselectivity in Bioaccumulation and excretion of epoxiconazole by mealworm beetle tenebrio molitor larvae
    Ecotoxicology and Environmental Safety, 2014
    Co-Authors: Xiaotian Lv, Chen Liu, Yaobin Li, Yong Xin Gao, Huili Wang, Jianzhong Li, Baoyuan Guo

    Abstract:

    Stereoselectivity in Bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20 mg/kg and 2 mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective Bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20 mg/kg dose. The stereoselectivity in Bioaccumulation in the 2 mg/kg dosage was not obvious compared to the 20 mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by Bioaccumulation Factor (BAF). (C) 2014 Elsevier Inc. All rights reserved.

  • Bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure.
    Chirality, 2013
    Co-Authors: Xiaotian Lv, Baoyuan Guo, Chen Liu, Yaobin Li, Yong Xin Gao, Huili Wang, Jianzhong Li

    Abstract:

    The Bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure under laboratory conditions were investigated using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. The wheat bran fed to Tenebrio molitor larvae was spiked with racemic myclobutanil at two dose levels of 20 mg/kg and 2 mg/kg (dry weight). The results showed that there was a significant trend of enantioselective Bioaccumulation in the larvae with a preferential accumulation of (−)-myclobutanil in 20 mg/kg dose exposure, but it was not obviously observed in the 2 mg/kg dose group. A kinetic model considering enantiomerization between the two enantiomers based on first-order reactions was built and the rate constants were estimated to discuss the kinetic reason for the different concentrations of individual enantiomers in the larvae. The approximations implied an inversion between the two enantiomers with a relatively higher rate of the inversion from (−)-myclobutanil to (+)-myclobutanil. Meanwhile, analysis of data of excretion samples suggested the active excretion is probably an important pathway for the insect to eliminate myclobutanil rapidly with nonenantioselectivity as a passive transport process, which was consistent with the low accumulation efficiency of myclobutanil measured by BAF (Bioaccumulation Factor). Chirality 25:890–896, 2013. © 2013 Wiley Periodicals, Inc.