The Experts below are selected from a list of 930 Experts worldwide ranked by ideXlab platform
Jiacheng E Yang - One of the best experts on this subject based on the ideXlab platform.
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novel magnetic rod like mn fe oxycarbide toward peroxymonosulfate activation for efficient oxidation of Butyl Paraben radical oxidation versus singlet oxygenation
Applied Catalysis B-environmental, 2020Co-Authors: Jiacheng E Yang, Yuan Lin, Huihui Peng, Baoling Yuan, Dionysios D Dionysiou, Xiaodan Huang, Dandan ZhangAbstract:Abstract A new peroxymonosulfate (PMS) oxidation system was constructed using a novel magnetic Mn-Fe oxycarbide (mMFC) as an activator. We found that the non-metal ( C O groups) and metal (Mn/Fe oxides) species within mMFC as dual active sites activated/catalyzed PMS synergistically to generate SO4 −, OH, 1O2 and O2 −, then 1O2 and/or O2 − served as a secondary driving force to form SO4 − and OH for Butyl Paraben (BPB) oxidation via a radical reaction process. The stability of mMFC and the effects of initial pH, dosages, solution temperature and environmental conditions on BPB oxidation kinetics were probed with a proposed catalytic mechanism of mMFC toward PMS activation for BPB oxidation. The revealed radical and singlet formation/evolutions and radical-controlled BPB degradation mechanisms in mMFC/PMS system would advance our knowledge of designing novel magnetic Mn-based oxycarbides with elaborate structures/properties toward PMS activation for effective oxidation of emerging contaminants in wastewater.
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yolk shell structured cofe2o4 microspheres as novel catalysts for peroxymonosulfate activation for efficient degradation of Butyl Paraben
RSC Advances, 2016Co-Authors: Chen Chen, Weiqi Zuo, Jiacheng E Yang, Haojie CuiAbstract:Three-dimensional yolk–shell structured CoFe2O4 microspheres were successfully prepared by hydrothermal method coupled calcination. The obtained magnetic yolk–shell microspheres exhibit excellent ability to activate peroxymonosulfate for efficient degradation of Butyl Paraben in wastewater followed by easy magnetic separation.
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synthetic conditions regulated catalytic oxone efficacy of mnox sba 15 towards Butyl Paraben bpb removal under heterogeneous conditions
Chemical Engineering Journal, 2016Co-Authors: Jiacheng E Yang, Huachun Lan, Xiaoqiong Lin, Baoling YuanAbstract:Abstract Heterogeneous catalysts prepared under different conditions usually demonstrate different catalytic performance, but the underlying influences are not well addressed. Therefore, MnOx/SBA-15 (MS) composites were fabricated under different synthetic conditions to probe the links between their changes in physicochemical features and catalytic Oxone efficacies, using Butyl Paraben (BPB) as a probe chemical. Characterization results demonstrated that the changes of Mn/SBA-15 weight ratio, calcination temperature and time altered the physic–chemical characteristics of MS composites such as the specific surface area and the types/amounts of MnOx species of MS composites. Further studies showed that these synthetic conditions had affected the catalytic Oxone performance of MS composites towards BPB removal through changing the types or the amounts of active radicals. The catalytic Oxone efficacy of the optimized MS was highly dependent on the changes of the dosages of MS and Oxone and the initial pH values of BPB solutions. SO4 − and OH were identified as the main reactive species of MS–Oxone system responsible for BPB removal. Additionally, the thermally activated MS demonstrated excellent catalytic Oxone efficacy during its recycles. These findings will increase the knowledge regarding the “synthetic conditions – physicochemical characteristics – application” centered-relationships of heterogeneous catalysts for water treatment.
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Yolk–shell structured CoFe2O4 microspheres as novel catalysts for peroxymonosulfate activation for efficient degradation of Butyl Paraben
RSC Advances, 2016Co-Authors: Chen Chen, Weiqi Zuo, Jiacheng E Yang, Haojie CuiAbstract:Three-dimensional yolk–shell structured CoFe2O4 microspheres were successfully prepared by hydrothermal method coupled calcination. The obtained magnetic yolk–shell microspheres exhibit excellent ability to activate peroxymonosulfate for efficient degradation of Butyl Paraben in wastewater followed by easy magnetic separation.
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Synthetic conditions-regulated catalytic Oxone efficacy of MnOx/SBA-15 towards Butyl Paraben (BPB) removal under heterogeneous conditions
Chemical Engineering Journal, 2016Co-Authors: Jiacheng E Yang, Huachun Lan, Xiaoqiong Lin, Baoling YuanAbstract:Abstract Heterogeneous catalysts prepared under different conditions usually demonstrate different catalytic performance, but the underlying influences are not well addressed. Therefore, MnOx/SBA-15 (MS) composites were fabricated under different synthetic conditions to probe the links between their changes in physicochemical features and catalytic Oxone efficacies, using Butyl Paraben (BPB) as a probe chemical. Characterization results demonstrated that the changes of Mn/SBA-15 weight ratio, calcination temperature and time altered the physic–chemical characteristics of MS composites such as the specific surface area and the types/amounts of MnOx species of MS composites. Further studies showed that these synthetic conditions had affected the catalytic Oxone performance of MS composites towards BPB removal through changing the types or the amounts of active radicals. The catalytic Oxone efficacy of the optimized MS was highly dependent on the changes of the dosages of MS and Oxone and the initial pH values of BPB solutions. SO4 − and OH were identified as the main reactive species of MS–Oxone system responsible for BPB removal. Additionally, the thermally activated MS demonstrated excellent catalytic Oxone efficacy during its recycles. These findings will increase the knowledge regarding the “synthetic conditions – physicochemical characteristics – application” centered-relationships of heterogeneous catalysts for water treatment.
Huaiyu Yang - One of the best experts on this subject based on the ideXlab platform.
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Effect of oscillatory flow on nucleation kinetics of Butyl Paraben
Crystal Growth & Design, 2016Co-Authors: Huaiyu Yang, Vishal Raval, Yassir Makkawi, Alastair J FlorenceAbstract:More than 165 induction times of Butyl Paraben-ethanol solution in a batch moving fluid oscillation baffled crystallizer with various amplitudes (1-9 mm) and frequencies (1.0-9.0 Hz) have been determined to study the effect of COBR operating conditions on nucleation. The induction time decreases with increasing amplitude and frequency at power density below about 500 W/m3; however, a further increase of the frequency and amplitude leads to an increase of the induction time. The interfacial energies and pre-exponential factors in both homogeneous and heterogeneous nucleation are determined by classical nucleation theory at oscillatory frequency 2.0 Hz and amplitudes of 3 or 5 mm both with and without net flow. To capture the shear rate conditions in oscillatory flow crystallizers, a large eddy simulation approach in a computational fluid dynamics framework is applied. Under ideal conditions the shear rate distribution shows spatial and temporal periodicity and radial symmetry. The spatial distributions of the shear rate indicate an increase of average and maximum values of the shear rate with increasing amplitude and frequency. In continuous operation, net flow enhances the shear rate at most time points, promoting nucleation. The mechanism of the shear rate influence on nucleation is discussed.
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Crystal structure of the co-crystal Butyl-Paraben-isonicotinamide (1/1).
Acta crystallographica. Section E Crystallographic communications, 2016Co-Authors: Rajni M Bhardwaj, Huaiyu Yang, Alastair J FlorenceAbstract:The title 1:1 co-crystal, C11H14O3·C6H6N2O [systematic name: Butyl 4-hy-droxy-benzoate-isonicotinamide (1/1)], crystallizes with one mol-ecule of Butyl-Paraben (BPN) and one mol-ecule of isonicotinamide (ISN) in the asymmetric unit. In the crystal, BPN and ISN mol-ecules form hydrogen-bonded (O-H⋯N and N-H⋯O) dimers of paired BPN and ISN mol-ecules. These dimers are further connected to each other via N-H⋯O=C hydrogen bonds, creating ribbons in [011] which further stack along the a axis to form a layered structure with short C⋯C contacts of 3.285 (3) Å. Packing inter-actions within the crystal structure were assessed using PIXEL calculations.
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Effect of Oscillatory Flow on Nucleation Kinetics of Butyl Paraben
2016Co-Authors: Huaiyu Yang, Vishal Raval, Yassir Makkawi, Alastair FlorenceAbstract:More than 165 induction times of Butyl Paraben–ethanol solution in a batch moving fluid oscillation baffled crystallizer with various amplitudes (1–9 mm) and frequencies (1.0–9.0 Hz) have been determined to study the effect of COBR operating conditions on nucleation. The induction time decreases with increasing amplitude and frequency at power density below about 500 W/m3; however, a further increase of the frequency and amplitude leads to an increase of the induction time. The interfacial energies and pre-exponential factors in both homogeneous and heterogeneous nucleation are determined by classical nucleation theory at oscillatory frequency 2.0 Hz and amplitudes of 3 or 5 mm both with and without net flow. To capture the shear rate conditions in oscillatory flow crystallizers, a large eddy simulation approach in a computational fluid dynamics framework is applied. Under ideal conditions the shear rate distribution shows spatial and temporal periodicity and radial symmetry. The spatial distributions of the shear rate indicate an increase of average and maximum values of the shear rate with increasing amplitude and frequency. In continuous operation, net flow enhances the shear rate at most time points, promoting nucleation. The mechanism of the shear rate influence on nucleation is discussed
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Relation between metastable zone width and induction time of Butyl Paraben in ethanol
CrystEngComm, 2015Co-Authors: Huaiyu YangAbstract:A relation between induction time and metastable zone width in cooling crystallization has been developed based on Classical Nucleation Theory, and an interpretation equation of this relation has been used to extrapolate metastable zone width from the induction time results in homogenous primary nucleation. The metastable zone width is determined by the interfacial energy and the pre-exponential factor. 440 metastable zone experiments of Butyl Paraben in ethanol at five different cooling rates have been performed. The experimental metastable zone widths of Butyl Paraben in ethanol are fairly close to those extrapolated from the induction time results. The positive correlation between the cooling rate and the experimental metastable zone width is in good agreement with the interpretation equation, from which the relations between stirring rate, saturation temperature and volume of solution with estimated metastable zone width have been investigated.
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Phase equilibrium and mechanisms of crystallization in liquid–liquid phase separating system
Fluid Phase Equilibria, 2015Co-Authors: Huaiyu Yang, Ake C RasmusonAbstract:Abstract The influence of liquid–liquid phase separation (LLPS) in a crystallizing system is examined, and the liquid–liquid tie lines are determined in the ternary system of Butyl Paraben, water and ethanol. Crystallization by evaporation in droplets (solution of Butyl Paraben in ethanol and water mixtures) of homogeneous solution and two-phase liquid mixtures on plates of different materials: glass, plastic, steel, and tin were investigated by microscopy. Different crystallization and liquid–liquid phase separation behaviour are observed depending on initial droplet composition and the surface material. This work reveals that crystallization in the LLPS solution of Butyl Paraben in ethanol–water mixtures starts in the Butyl Paraben rich phase as can be explained by a higher Butyl Paraben concentration, and a lower solid–liquid interfacial energy.
Ake C Rasmuson - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the Solubility of Medium-Sized Pharmaceutical Compounds Using a Temperature-Dependent NRTL-SAC Model
Industrial & Engineering Chemistry Research, 2016Co-Authors: Masood Valavi, Michael Svard, Ake C RasmusonAbstract:In this work, the NRTL-SAC and the Pharma UNIFAC models are evaluated with respect to the capability of prediction of solid–liquid equilibria of pharmaceutical compounds in organic solvents. The original NRTL-SAC model is extended through the introduction of temperature-dependent binary interaction parameters, and the two versions of the model are parametrized using vapor–liquid equilibrium (VLE) data. The performance of the NRTL-SAC models for correlation and prediction of the solubility of eight medium-sized flexible pharmaceutical or pharmaceutically similar molecules in multiple pure, organic solvents is examined: risperidone, fenofibrate, fenoxycarb, tolbutamide, meglumine, Butyl Paraben, butamben, and salicylamide. The performance of the Pharma UNIFAC model is evaluated using data for six of these compounds. In general, it is found that introducing a dependence on temperature to the binary interaction parameters of the NRTL-SAC model can improve its capability for modeling and prediction of the solu...
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influence of agitation on primary nucleation in stirred tank crystallizers
Crystal Growth & Design, 2015Co-Authors: Michael Svard, Ake C RasmusonAbstract:The influence of agitation on nucleation of Butyl Paraben and m-hydroxybenzoic acid polymorphs has been investigated through 330 cooling crystallization experiments. The induction time has been measured at different supersaturations and temperatures in three parallel jacketed vessels equipped with different overhead stirring agitators. In each case, the nucleating polymorph of m-hydroxybenzoic acid has been identified by infrared spectroscopy. The influences of agitation rate, impeller type, impeller diameter, impeller to bottom clearance, and the use of baffles have been investigated. A general trend in all of the experiments is that the induction time decreases with increasing agitation rate. Across all experiments with different fluid mechanics for the Butyl Paraben system, the induction time is correlated to the average energy dissipation rate raised to the power −0.3. It is shown that this dependence is consistent with a turbulent flow enhanced cluster coalescence mechanism. In experiments with m-hyd...
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Phase equilibrium and mechanisms of crystallization in liquid–liquid phase separating system
Fluid Phase Equilibria, 2015Co-Authors: Huaiyu Yang, Ake C RasmusonAbstract:Abstract The influence of liquid–liquid phase separation (LLPS) in a crystallizing system is examined, and the liquid–liquid tie lines are determined in the ternary system of Butyl Paraben, water and ethanol. Crystallization by evaporation in droplets (solution of Butyl Paraben in ethanol and water mixtures) of homogeneous solution and two-phase liquid mixtures on plates of different materials: glass, plastic, steel, and tin were investigated by microscopy. Different crystallization and liquid–liquid phase separation behaviour are observed depending on initial droplet composition and the surface material. This work reveals that crystallization in the LLPS solution of Butyl Paraben in ethanol–water mixtures starts in the Butyl Paraben rich phase as can be explained by a higher Butyl Paraben concentration, and a lower solid–liquid interfacial energy.
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Sandwich crystals of Butyl Paraben
CrystEngComm, 2014Co-Authors: Huaiyu Yang, Hong Chen, Ake C RasmusonAbstract:Butyl Paraben crystals having a porous layer in between two solid non-porous layers have been produced by cooling crystallization in mixtures of ethanol and water. The outer layers are transparent and fully crystalline, while the middle layer appears to be polycrystalline and is full of pores of various dimensions, down to below 0.1 μm diameters. The thickness of the porous layer reaches about 40% of the whole crystal. The crystals contain one polymorph only and appear to be essentially fully crystalline. They are stable for more than a year when stored on the shelf at room temperature. When the crystals dissolve, the porous layer dissolves faster, leaving the outer layers for slower dissolution. The sandwich crystals are easily cleaved through the middle layer parallel to the (100) plane. This type of sandwich crystals may provide new useful properties to pharmaceutical solids, e.g. larger specific surface area, higher dissolution rates and improved compaction properties.
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Ternary phase diagrams of ethyl Paraben and propyl Paraben in ethanol aqueous solvents
Fluid Phase Equilibria, 2014Co-Authors: Huaiyu Yang, Ake C RasmusonAbstract:Three ternary phase diagrams of ethyl Paraben, ethanol, water and propyl Paraben, ethanol, water have been determined. The liquid-liquid phase separation has been reported in these three ternary diagrams. In pure water the ethyl Paraben and propyl Paraben solubility is both below 1. mg/g, while in pure ethanol the solubility is more than three orders of magnitude higher. While the solution saturated with propyl Paraben is homogeneous at 30.0. °C, and the solution saturated with ethyl Paraben is homogenous at 40.0. °C, however, the higher temperatures induce liquid-liquid phase separation in the ethanol-water mixtures, and the ternary phase diagrams contain five different regions. The size of the liquid-liquid phase separation region increases with increasing temperature. The systematic changes of thermodynamic properties between Butyl Paraben, propyl Paraben and ethyl Paraben have been investigated.
Baoling Yuan - One of the best experts on this subject based on the ideXlab platform.
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novel magnetic rod like mn fe oxycarbide toward peroxymonosulfate activation for efficient oxidation of Butyl Paraben radical oxidation versus singlet oxygenation
Applied Catalysis B-environmental, 2020Co-Authors: Jiacheng E Yang, Yuan Lin, Huihui Peng, Baoling Yuan, Dionysios D Dionysiou, Xiaodan Huang, Dandan ZhangAbstract:Abstract A new peroxymonosulfate (PMS) oxidation system was constructed using a novel magnetic Mn-Fe oxycarbide (mMFC) as an activator. We found that the non-metal ( C O groups) and metal (Mn/Fe oxides) species within mMFC as dual active sites activated/catalyzed PMS synergistically to generate SO4 −, OH, 1O2 and O2 −, then 1O2 and/or O2 − served as a secondary driving force to form SO4 − and OH for Butyl Paraben (BPB) oxidation via a radical reaction process. The stability of mMFC and the effects of initial pH, dosages, solution temperature and environmental conditions on BPB oxidation kinetics were probed with a proposed catalytic mechanism of mMFC toward PMS activation for BPB oxidation. The revealed radical and singlet formation/evolutions and radical-controlled BPB degradation mechanisms in mMFC/PMS system would advance our knowledge of designing novel magnetic Mn-based oxycarbides with elaborate structures/properties toward PMS activation for effective oxidation of emerging contaminants in wastewater.
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synthetic conditions regulated catalytic oxone efficacy of mnox sba 15 towards Butyl Paraben bpb removal under heterogeneous conditions
Chemical Engineering Journal, 2016Co-Authors: Jiacheng E Yang, Huachun Lan, Xiaoqiong Lin, Baoling YuanAbstract:Abstract Heterogeneous catalysts prepared under different conditions usually demonstrate different catalytic performance, but the underlying influences are not well addressed. Therefore, MnOx/SBA-15 (MS) composites were fabricated under different synthetic conditions to probe the links between their changes in physicochemical features and catalytic Oxone efficacies, using Butyl Paraben (BPB) as a probe chemical. Characterization results demonstrated that the changes of Mn/SBA-15 weight ratio, calcination temperature and time altered the physic–chemical characteristics of MS composites such as the specific surface area and the types/amounts of MnOx species of MS composites. Further studies showed that these synthetic conditions had affected the catalytic Oxone performance of MS composites towards BPB removal through changing the types or the amounts of active radicals. The catalytic Oxone efficacy of the optimized MS was highly dependent on the changes of the dosages of MS and Oxone and the initial pH values of BPB solutions. SO4 − and OH were identified as the main reactive species of MS–Oxone system responsible for BPB removal. Additionally, the thermally activated MS demonstrated excellent catalytic Oxone efficacy during its recycles. These findings will increase the knowledge regarding the “synthetic conditions – physicochemical characteristics – application” centered-relationships of heterogeneous catalysts for water treatment.
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Synthetic conditions-regulated catalytic Oxone efficacy of MnOx/SBA-15 towards Butyl Paraben (BPB) removal under heterogeneous conditions
Chemical Engineering Journal, 2016Co-Authors: Jiacheng E Yang, Huachun Lan, Xiaoqiong Lin, Baoling YuanAbstract:Abstract Heterogeneous catalysts prepared under different conditions usually demonstrate different catalytic performance, but the underlying influences are not well addressed. Therefore, MnOx/SBA-15 (MS) composites were fabricated under different synthetic conditions to probe the links between their changes in physicochemical features and catalytic Oxone efficacies, using Butyl Paraben (BPB) as a probe chemical. Characterization results demonstrated that the changes of Mn/SBA-15 weight ratio, calcination temperature and time altered the physic–chemical characteristics of MS composites such as the specific surface area and the types/amounts of MnOx species of MS composites. Further studies showed that these synthetic conditions had affected the catalytic Oxone performance of MS composites towards BPB removal through changing the types or the amounts of active radicals. The catalytic Oxone efficacy of the optimized MS was highly dependent on the changes of the dosages of MS and Oxone and the initial pH values of BPB solutions. SO4 − and OH were identified as the main reactive species of MS–Oxone system responsible for BPB removal. Additionally, the thermally activated MS demonstrated excellent catalytic Oxone efficacy during its recycles. These findings will increase the knowledge regarding the “synthetic conditions – physicochemical characteristics – application” centered-relationships of heterogeneous catalysts for water treatment.
Anna-maria Andersson - One of the best experts on this subject based on the ideXlab platform.
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prenatal exposure to Butyl Paraben is associated with fat percentage in 7 year old boys
The Journal of Clinical Endocrinology and Metabolism, 2021Co-Authors: Anna-maria Andersson, Hanne Frederiksen, Frederik Damsgaard Hojsager, Henriette Boye Kyhl, Anders Juul, Marianne AndersenAbstract:Context Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to Butyl Paraben and overweight in childhood, with a stronger trend in girls. Objective We therefore studied the association between Parabens in maternal urine in third trimester and fat percentage in children aged 7 years. Design, setting & participants We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010-2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by Dual Xray Absorptiometry in their children at age 7 years. Main outcome measurements Total, Gynoid, and Android fat percentages and z-score for BMI. Interventions None. Results Paraben exposure was low. In multivariate linear regressions, detection of ButylParaben in maternal urine was associated with an increase of 17% (95% confidence intervals CI 3.0%;32%) in total body fat percentage and an increase of 23% (95% CI 5.1%;43%) in android fat percentage in boys, compared to boys whose mother had no detectable ButylParaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl Parabens and body composition were found, and no significant associations were seen in girls. Conclusion Our findings suggest that Parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development.
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Prenatal exposure to Butyl Paraben is associated with fat percentage in 7-year old boys.
The Journal of clinical endocrinology and metabolism, 2021Co-Authors: Frederik Damsgaard Højsager, Anna-maria Andersson, Hanne Frederiksen, Henriette Boye Kyhl, Anders Juul, Marianne Skovsager Andersen, Anders Grøntved, Tina Kold JensenAbstract:Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to Butyl Paraben and overweight in childhood, with a stronger trend in girls. We therefore studied the association between Parabens in maternal urine in third trimester and fat percentage in children aged 7 years. We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010-2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by Dual Xray Absorptiometry in their children at age 7 years. Total, Gynoid, and Android fat percentages and z-score for BMI. None. Paraben exposure was low. In multivariate linear regressions, detection of ButylParaben in maternal urine was associated with an increase of 17% (95% confidence intervals CI 3.0%;32%) in total body fat percentage and an increase of 23% (95% CI 5.1%;43%) in android fat percentage in boys, compared to boys whose mother had no detectable ButylParaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl Parabens and body composition were found, and no significant associations were seen in girls. Our findings suggest that Parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development. © The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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systemic uptake of diethyl phthalate diButyl phthalate and Butyl Paraben following whole body topical application and reproductive and thyroid hormone levels in humans
Environmental Science & Technology, 2007Co-Authors: Nadeem Rezaq Janjua, Gerda Krogh Mortensen, Brian Kongshoj, Niels E Skakkebaek, Anna-maria Andersson, Hans Christian WulfAbstract:In vitro and animal studies have reported endocrine-disrupting activity of chemicals used commonly as additives in cosmetics and skin care products. We investigated whether diethyl phthalate (DEP), diButyl phthalate (DBP), and Butyl Paraben (BP) were systemically absorbed and influenced endogenous reproductive and thyroid hormone levels in humans after topical application. In a two-week single-blinded study, 26 healthy young male volunteers were assigned to daily whole-body topical application of 2 mg/cm2 basic cream formulation each without (week one) and with (week two) the three 2% (w/w) compounds. The concentrations of BP and the main phthalate metabolites monoethyl (MEP) and monoButyl phthalate (MBP) were measured in serum together with the following reproductive hormones: follicle stimulating hormone (FSH), lutenising hormone (LH), testosterone, estradiol, and inhibin B and thyroid hormones (thyroid stimulating hormone (TSH), free thyroxine (FT4), total triiodothyroxine (T3), and total thyroxine (T...
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Systemic uptake of diethyl phthalate, diButyl phthalate, and Butyl Paraben following whole-body topical application and reproductive and thyroid hormone levels in humans
Environmental Science and Technology, 2007Co-Authors: Nadeem Rezaq Janjua, Gerda Krogh Mortensen, Brian Kongshoj, Niels E Skakkebaek, Anna-maria Andersson, Hans Christian WulfAbstract:In vitro and animal studies have reported endocrine-disrupting activity of chemicals used commonly as additives in cosmetics and skin care products. We investigated whether diethyl phthalate (DEP), diButyl phthalate (DBP), and Butyl Paraben (BP) were systemically absorbed and influenced endogenous reproductive and thyroid hormone levels in humans after topical application. In a two-week single-blinded study, 26 healthy young male volunteers were assigned to daily whole-body topical application of 2 mg/cm2 basic cream formulation each without (week one) and with (week two) the three 2% (w/w) compounds. The concentrations of BP and the main phthalate metabolites monoethyl (MEP) and monoButyl phthalate (MBP) were measured in serum together with the following reproductive hormones: follicle stimulating hormone (FSH), lutenising hormone (LH), testosterone, estradiol, and inhibin B and thyroid hormones (thyroid stimulating hormone (TSH), free thyroxine (FT4), total triiodothyroxine (T3), and total thyroxine (T4)). MEP, MBP, and BP peaked in serum a few hours after application, reaching mean +/- SEM levels of 1001 +/- 81 microg/L, 51 +/- 6 microg/ L, and 135 +/- 11 microg/L, respectively. Only MEP was detectable in serum before treatment. Minor differences in inhibin B, LH, estradiol, T4, FT4, and TSH were observed between the two weeks, but these were not related to exposure. We demonstrated for the first time that DEP, DBP, and BP could be systemically absorbed in man after topical application. The systemic absorption of these compounds did not seem to have any short-term influence on the levels of reproductive and thyroid hormones in the examined young men.
