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  • 1
    Language: English
    Description: The fate and behaviour of estrogens in the environment are of concern due to the compounds’ endocrine disruption potential. Estrogens, namely 17β-estradiol (E2), estrone (E1), and estrogen sulphates, i.e. 17β-estradiol-3-sulphate (E2-3S) and estrone-3-sulphate (E1-3S) excreted by livestock constitute a potential source for estrogen contamination in the environment. A method was developed to separate and quantify the hormones by high-performance-liquid-chromatography (HPLC) and ultraviolet detection (UV). A combination of dichloromethane (DCM) and dicyclohexylamine hydrochloride (DCH·HCl) gave recoveries from 97.3 to 107% for E1-3S extraction from aqueous solutions. The recoveries from soil samples ranged from 80.9 to 95.2% (E2-3S), and from 86.3 to 91.7% (E1-3S), respectively. Results of batch sorption studies showed that Freundlich isotherms were nonlinear (N ≠ 1) with Kf values ranging from 34.2 to 57.2, and from 3.42 to 4.18 mg¹-N LN kg⁻¹ for E1, and E1-3S, respectively, indicating the sorption affinity of E1-3S was about an order of magnitude lower than that of E1. The hydrophilic sulphate group of E1-3S possibly shielded the compound from hydrophobic interactions with the soil organic matter and allophanic clay minerals that were proposed as sorbents for E1. Contraction of clay minerals, “salting out” and competitive sorption of artificial urine constituents were likely to have been responsible for observed changes in Freundlich parameters when artificial urine was used as mediator matrix. Plotting the effective distribution coefficient as a function of hypothetical exposure concentrations facilitated the comparison of the sorption behaviour of both compounds as influenced by the mediator solution. The results emphasized that using the CaCl₂ matrix might result in false inferences for the sorption behaviour of these compounds in a dairying environment. The four hormones rapidly degraded in the agricultural soils under aerobic conditions, and the majority of the compounds degraded 〉 50% within the first 24 hrs. Soil arylsulphatase activities were directly correlated with degradation rate constants of the estrogen sulphates. Estrone was identified as a metabolite of E2 and E1-3S, and these three compounds were observed as metabolites of E2-3S. Single-first order (SFO) and double first-order in parallel (DFOP) kinetics were used to model the degradation and metabolite formation data. The results showed that the DFOP model was in most cases better able to predict the parent compound degradation than the SFO model, and also enabled to estimate accurate degradation endpoints. ER-CALUX® analysis revealed the formation of estrogenicity during E2-3S degradation, which could partly be explained by the formation of the metabolites E2 and E1. Transport studies with E1-3S and E1 showed that the transport and retention of both compounds were significantly influenced by the mediator matrix. While no breakthrough curves (BTCs) were recorded during hormone application in CaCl₂ (10 mM) both hormones were detected in the leachate when applied in artificial urine. Rate-limited sorption processes were proposed for the delayed arrival of the hormone BTCs compared with a conservative bromide tracer. Intense colouration of the leachate during the artificial urine experiments suggested the hormones were likely to be moved by colloid-facilitated transport. Furthermore, the detection of residue hormone and metabolite concentrations implied that degradation of E1-3S and E1 was hampered by urine constituents such as glycine and urea.
    Keywords: 17-Beta-Estradiol ; Estrone ; 17-Beta-Estradiol-3-Sulphate ; Estrone-3-Sulphate ; Sorption ; Degradation ; Transport ; Er-Calux ; Kinetic Modelling ; Arylsulphatase Activity ; Metabolite Formation ; Artificial Urine ; Fields Of Research::300000 Agricultural ; Veterinary And Environmental Sciences::300100 Soil And Water Sciences::300103 Soil Chemistry ; Fields Of Research::250000 Chemical Sciences::259900 Other Chemical Sciences::259902 Environmental Chemistry (Incl. Atmospheric Chemistry)
    Source: Networked Digital Library of Theses and Dissertations
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  • 2
    Language: English
    In: Chemosphere, July, 2014, Vol.107, p.13(10)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chemosphere.2014.02.055 Byline: Christoph Stang, Matthias Valentin Wieczorek, Christian Noss, Andreas Lorke, Frank Scherr, Gerhard Goerlitz, Ralf Schulz Abstract: acents Aquatic macrophytes determine how dispersion and sorption mitigate PPPs in streams. acents Sparse vegetation fosters dispersion. acents Dense vegetation fosters mass retention. acents Compound related and time limited mass retention compensates diminished dispersion. Article History: Received 11 September 2013; Revised 21 January 2014; Accepted 4 February 2014 Article Note: (miscellaneous) Handling Editor: X. Cao
    Keywords: Closed Experimental Ecosystems
    ISSN: 0045-6535
    Source: Cengage Learning, Inc.
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  • 3
    Language: English
    In: Chemosphere, July 2014, Vol.107, pp.13-22
    Description: Quantitative information on the processes leading to the retention of plant protection products (PPPs) in surface waters is not available, particularly for flow-through systems. The influence of aquatic vegetation on the hydraulic- and sorption-mediated mitigation processes of three PPPs (triflumuron, pencycuron, and penflufen; log 3.3–4.9) in 45-m slow-flowing stream mesocosms was investigated. Peak reductions were 35–38% in an unvegetated stream mesocosm, 60–62% in a sparsely vegetated stream mesocosm (13% coverage with ), and in a similar range of 57–69% in a densely vegetated stream mesocosm (100% coverage). Between 89% and 93% of the measured total peak reductions in the sparsely vegetated stream can be explained by an increase of vegetation-induced dispersion (estimated with the one-dimensional solute transport model OTIS), while 7–11% of the peak reduction can be attributed to sorption processes. However, dispersion contributed only 59–71% of the peak reductions in the densely vegetated stream mesocosm, where 29% to 41% of the total peak reductions can be attributed to sorption processes. In the densely vegetated stream, 8–27% of the applied PPPs, depending on the log values of the compounds, were temporarily retained by macrophytes. Increasing PPP recoveries in the aqueous phase were accompanied by a decrease of PPP concentrations in macrophytes indicating kinetic desorption over time. This is the first study to provide quantitative data on how the interaction of dispersion and sorption, driven by aquatic macrophytes, influences the mitigation of PPP concentrations in flowing vegetated stream systems.
    Keywords: Pesticide ; Plant Protection Product ; Dispersion ; Sorption ; Vegetated Stream Mesoscosms ; Tracer ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 4
    Language: English
    In: Journal of Environmental Science and Health, Part B, 01 November 2011, Vol.46(8), pp.763-772
    Description: A simple and robust analytical method was developed to simultaneously detect and quantify 17β-estradiol (E2), estrone (E1), 17β-estradiol-3-sulphate (E2-3S), and estrone-3-sulphate (E1-3S) in aqueous solutions (calcium chloride and artificial...
    Keywords: 17β-Estradiol ; Estrone ; 17β-Estradiol-3-Sulphate ; Estrone-3-Sulphate ; Engineering ; Ecology
    ISSN: 0360-1234
    E-ISSN: 1532-4109
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  • 5
    Language: English
    In: Water, air, and soil pollution, 2007, Vol.182(1), pp.31-41
    Description: Methylation and demethylation of arsenic may change substantially the toxicity and mobility of arsenic in soils. Little is known about demethylation of organic arsenic species in organic soils. We incubated dimethylarsinic acid (DMA) and arsenobetaine (AsB) in soils and aqueous soil extracts from a forest floor and fen, in order to investigate demethylation processes. Incubations were conducted at 5°C in the dark under oxic or anoxic conditions. Arsenobetaine demethylated rapidly in all soil extracts with half-lives of 3.6-12 days, estimated from first order kinetic. Demethylation of DMA was relatively slow with half-lives of 187 and 46 days in the forest floor extracts and oxic fen extracts, respectively. In comparison, DMA was stable for 100 days in anoxic fen extracts. The apparent half-lives were much shorter in soils for DMA (1.3-12.6 days) and AsB (0.5-1.9 days) than in soil extracts, suggesting also irreversible AsB and DMA adsorption to soils beside demethylation. An unknown arsenic species and DMA were detected as metabolites of AsB demethylation. The results indicate rapid demethylation of AsB probably via the pathway AsB [rightward arrow] Dimethylarsenoylacetate [rightward arrow] DMA, followed up by slow demethylation of DMA [rightward arrow] monomethylarsonic acid [rightward arrow] inorganic As species. ; Includes references ; p. 31-41.
    Keywords: Forest Soils ; Methylation ; Soil Biochemistry ; Aerobic Conditions ; Organic Soils ; Cacodylic Acid ; Arsenic ; Anaerobic Conditions ; Forest Litter ; Soil Pollution ; Fen Soils ; Chemical Speciation ; Polluted Soils
    ISSN: 0049-6979
    E-ISSN: 15732932
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  • 6
    Language: English
    In: Environment International, 2009, Vol.35(2), pp.291-297
    Description: Estrogens-sulphates such as 17 -estradiol-3-sulphate and estrone-3-sulphate are excreted by livestock in the urine. These conjugates are precursors to the free counterparts 17 estradiol and estrone, which are endocrine disrupting chemicals. In this study microcosm laboratory experiments were conducted in three pasture soils from New Zealand to study the aerobic degradation and metabolite formation kinetics of 17 -estradiol-3-sulphate at three different incubation temperatures. The degradation of 17 -estradiol-3-sulphate followed a first-order kinetic and the temperature dependence of the rate constants was sufficiently described by the Arrhenius equation. Degradation was different between the three investigated soils and the rate constants across the soils were significantly correlated to the arylsulphatase activity at 7.5 and 15 °C. Estrone-3-sulphate and 17 -estradiol were identified as primary metabolites and estrone as a secondary metabolite. Results suggest arylsulphatase activity originating from soil microbial biomass is the main driver for the degradation of 17 -estradiol-3-sulphate.
    Keywords: 17 Β-Estradiol ; Estrone ; Estrogen-Sulphates ; Degradation ; Arylsulphatase Activity ; Engineering ; Environmental Sciences ; Public Health
    ISSN: 0160-4120
    E-ISSN: 1873-6750
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  • 7
    Language: English
    In: Water, Air, and Soil Pollution, 2007, Vol.182(1), pp.31-41
    Description: Methylation and demethylation of arsenic may change substantially the toxicity and mobility of arsenic in soils. Little is known about demethylation of organic arsenic species in organic soils. We incubated dimethylarsinic acid (DMA) and arsenobetaine (AsB) in soils and aqueous soil extracts from a forest floor and fen, in order to investigate demethylation processes. Incubations were conducted at 5°C in the dark under oxic or anoxic conditions. Arsenobetaine demethylated rapidly in all soil extracts with half-lives of 3.6–12 days, estimated from first order kinetic. Demethylation of DMA was relatively slow with half-lives of 187 and 46 days in the forest floor extracts and oxic fen extracts, respectively. In comparison, DMA was stable for 100 days in anoxic fen extracts. The apparent half-lives were much shorter in soils for DMA (1.3–12.6 days) and AsB (0.5–1.9 days) than in soil extracts, suggesting also irreversible AsB and DMA adsorption to soils beside demethylation. An unknown arsenic species and DMA were detected as metabolites of AsB demethylation. The results indicate rapid demethylation of AsB probably via the pathway AsB → Dimethylarsenoylacetate → DMA, followed up by slow demethylation of DMA → monomethylarsonic acid → inorganic As species.
    Keywords: arsenic ; methylation ; demethylation ; forest floor ; fen
    ISSN: 0049-6979
    E-ISSN: 1573-2932
    Source: Springer Science & Business Media B.V.
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  • 8
    Language: English
    In: Environment International, 2008, Vol.34(6), pp.749-755
    Description: We performed batch sorption experiments for 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) on selected soils collected from dairy farming regions of New Zealand. Isotherms were constructed by measuring the liquid phase concentration and extracting the solid phase with dichloromethane, followed by an exchange step, and analysis by HPLC and UV detection. The corresponding metabolite estrone, (E1) formed during equilibration of E2 with soil was taken into account to estimate the total percentage recoveries for the compounds, which ranged from 47–105% (E2 and E1) and 83–102% (EE2). Measured isotherms were linear, although some deviation from linearity was observed in a few soils, which was attributed to the finer textured particles and/or the allophanic nature of the soils having high surface area. There was a marked difference in (effective distribution coefficient) values for E2 and EE2 among the soils, consistent with the soils organic carbon content and ranged from 14–170 L kg (E2), and 12–40 L kg (EE2) in the soils common for both compounds. The sorption affinity of hormones in the soils followed an order: EE2 〈 E1 〈 E2 in Manawatu and Horotiu soils, and, E1 〈 EE2 〈 E2 in Pukekohe soil with average log of about 3 (± 0.1– 0.2 log units) which was consistent with earlier published values. Formation of the transformation product E1 appears to be concomitant with E2 sorption in all but one soil. Given that quite a large amount of E1 was generated during 72 h of contact time, and given E1 sorbed to solid phases greater than the liquid phase, dissolved organic carbon facilitated transport of these hormones needs to be considered when assessing the leaching risk for these compounds in the environment.
    Keywords: 17β-Estradiol ; Estrone ; 17α-Ethynylestradiol ; Sorption ; Non-Linearity ; Engineering ; Environmental Sciences ; Public Health
    ISSN: 0160-4120
    E-ISSN: 1873-6750
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  • 9
    Language: English
    In: Environmental Toxicology and Chemistry, December 2009, Vol.28(12), pp.2564-2571
    Description: Estrone (E1) and its sulfate conjugate estrone‐3‐sulfate (E1–3S) are released to the environment in animal wastes in significant amounts, and direct exposure occurs in grazed pasture systems. Both compounds have been shown to potentially contribute to endocrine disruption in wildlife, and knowledge about the sorption behavior of these compounds is necessary for a sound risk assessment. For labile compounds such as E1 and E1–3S, however, the standard protocols might overestimate sorption by not considering metabolite formation or allowing for equilibration that exceeds the commonly reported half‐lives of these compounds. We therefore conducted modified batch sorption experiments with 0.005 M calcium chloride (CaCl) and artificial urine solution to determine the influence of the mediator solution on the sorption of E1 and E1–3S in three pasture soils from New Zealand. Sorption isotherms of both compounds were nonlinear, and the Freundlich equation was found adequate to describe the isotherms. The sorption potential of E1–3S was about one order of magnitude lower than for the free counterpart, and the values significantly changed between the two mediator solutions. The calculation of concentration‐dependent effective distribution coefficients () revealed that for a range of realistic exposure concentrations in a grazed dairy system, the common approach of using CaCl would deliver incorrect inferences for a sound risk assessment.
    Keywords: Estrone‐3‐Sulfate ; Estrone ; Sorption ; Artificial Urine ; Effective Distribution Coefficient
    ISSN: 0730-7268
    E-ISSN: 1552-8618
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  • 10
    Language: English
    In: Environmental science & technology, 15 November 2008, Vol.42(22), pp.8388-94
    Description: Estrone-3-sulfate (E1-3S), formed in the kidneys of pregnant cattle, can act as a precursor to the free hormone estrone (E1) known for its endocrine disrupting potential in wildlife. Laboratory microcosm studies were conducted to investigate the aerobic degradation of E1-3S in three contrasting pasture soils at 7.5, 15, and 25 degrees C. Deconjugation of E1-3S resulted in the formation of the metabolite E1. Two kinetic models-a single first-order and a biexponential kinetic model-were applied to fit the observed degradation dynamics and to derive degradation end-points (DT50 and DT90) for the parent compound and the metabolite for each condition. Model selection and evaluation of their performance were based on a suit of statistical measures (one-way ANOVA, AIC(c), R2(adj), chi2 error-%, and SRMSE). The results showed rapid initial degradation of E1-3S, followed by a much slower decline with time, and rate of degradation was temperature dependent. The DT50 and DT90 values of E1-3S ranged from a few hours to several days, while the formation of the major metabolite (E1) was concomitant with E1-3S degradation in all nonsterile soils. The parent compound degradation and formation and subsequent dissipation of metabolite were successfully predicted by both models, however, the nonlinear biexponential model improved the goodness-of-fit parameters in most cases.
    Keywords: Agriculture ; Soil ; Estrone -- Analogs & Derivatives ; Soil Pollutants -- Metabolism
    ISSN: 0013-936X
    E-ISSN: 15205851
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