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Sample records for hydrogen phthalate single

  1. 2-Amino-4-methoxy-6-methylpyrimidinium hydrogen phthalate

    Directory of Open Access Journals (Sweden)

    Ramalingam Sangeetha

    2016-05-01

    Full Text Available In the hydrogen phthalate anion of the title molecular salt, C6H10N3O+·C8H5O4−, the dihedral angles formed by the benzene ring and the mean planes of the –COOH and –COO− groups are 16.1 (3 and 19.8 (3°, respectively. There is an intramolecular O—H...O hydrogen bond in the anion generating an S(7 ring motif. In the crystal, the protonated N atom of the pyrimidinium ring and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H...O hydrogen bonds, forming an R22(8 ring motif. The ion pairs are further connected via N—H...O and C—H...O hydrogen bonds, forming ribbons parallel to the [01-1] direction. The ribbons are linked by off-set π–π stacking interactions [intercentroid distances = 3.8279 (16 and 3.6074 (15 Å], forming a three-dimensional structure.

  2. Hierarchically organized architecture of potassium hydrogen phthalate and poly(acrylic acid): toward a general strategy for biomimetic crystal design.

    Science.gov (United States)

    Oaki, Yuya; Imai, Hiroaki

    2005-12-28

    A hierarchically organized architecture in multiple scales was generated from potassium hydrogen phthalate crystals and poly(acrylic acid) based on our novel biomimetic approach with an exquisite association of polymers on crystallization.

  3. Adsorption of triton X100 and potassium hydrogen phthalate on granular activated carbon from date pits

    Energy Technology Data Exchange (ETDEWEB)

    Merzougui, Z.; Nedjah, S.; Azoudj, Y.; Addoun, F. [Laboratoire d' etude physic-chimique des materiaux et application a l' environnement, Faculte de Chimie, USTHB (Algeria)], E-mail: zmerzougi@yahoo.fr

    2011-07-01

    Activated carbons, thanks to their versatility, are being used in the water treatment sector to absorb pollutants. Several factors influence the adsorption capacity of activated carbon and the aim of this study was to assess the effects of the porous texture and chemical nature of activated carbons on the adsorption of triton X100 and potassium hydrogen phthalate. Activated carbons used in this study were prepared from date pits with ZnCl2, KOH and H3PO4 by carbonization without adjuvant and adsorption of triton X100 and potassium hydrogen phthalate was conducted at 298K. Results showed that activated carbons prepared from date pits have a great potential for removing organic and inorganic pollutants from water and that the adsorption potential depends on the degree of activation of the activated carbons and on the compounds to absorb. This study highlighted that an increase of the carbon surface area and porosity results in a better adsorption capacity.

  4. 2-Methyl-1H-benzimidazol-3-ium hydrogen phthalate

    Directory of Open Access Journals (Sweden)

    YuanQi Yu

    2011-10-01

    Full Text Available The asymmetric unit of the title compound, C8H9N2+·C8H5O4−, contains two independent ion pairs. In each 2-methyl-1H-benzimidazolium ion, an intramolecular O—H...O bond forms an S(7 graph-set motif. In the crystal, the components are linked by N—H...O hydrogen bonds, forming chains along [210]. Further stabilization is provided by weak C—H...O hydrogen bonds.

  5. Crystal structure of 3,4-dichloroanilinium hydrogen phthalate

    Directory of Open Access Journals (Sweden)

    Muhammad Shahid

    2015-07-01

    Full Text Available In the title salt, C6H6Cl2N+·C8H5O4−, the carboxylic acid and carboxylate groups of the anion form dihedral angles of 20.79 (19 and 74.76 (14°, respectively, with the plane of the benzene ring. In the crystal, molecules are assembled into a two-dimensional polymeric network parallel to (100 via N—H...O and O—H...O hydrogen bonds. In addition, within the layer, there are π–π stacking interactions between the benzene rings of the cation and the anion [centroid–centroid distance = 3.6794 (17 Å]. A weak C—H...O interaction is also observed.

  6. Production of Plant Phthalate and its Hydrogenated Derivative from Bio-Based Platform Chemicals.

    Science.gov (United States)

    Lu, Rui; Lu, Fang; Si, Xiaoqin; Jiang, Huifang; Huang, Qianqian; Yu, Weiqiang; Kong, Xiangtao; Xu, Jie

    2018-04-06

    Direct transformation of bio-based platform chemicals into aromatic dicarboxylic acids and their derivatives, which are widely used for the manufacture of polymers, is of significant importance for the sustainable development of the plastics industry. However, limited successful chemical processes have been reported. This study concerns a sustainable route for the production of phthalate and its hydrogenated derivative from bio-based malic acid and erythritol. The key Diels-Alder reaction is applied to build a substituted cyclohexene structure. The dehydration reaction of malic acid affords fumaric acid with 96.6 % yield, which could be used as the dienophile, and 1,3-butadiene generated in situ through erythritol deoxydehydration serves as the diene. Starting from erythritol and dibutyl fumarate, a 74.3 % yield of dibutyl trans-4-cyclohexene-1,2-dicarboxylate is obtained. The palladium-catalyzed dehydrogenation of the cycloadduct gives a 77.8 % yield of dibutyl phthalate. Dibutyl trans-cyclohexane-1,2-dicarboxylate could be formed in nearly 100 % yield under mild conditions by hydrogenation of the cycloadduct. Furthermore, fumaric acid and fumarate, with trans configurations, were found to be better dienophiles for this Diels-Alder reaction than maleic acid and maleate, with cis configuration, based on the experimental and computational results. This new route will pave the way for the production of environmental friendly plastic materials from plants. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Phthalate Intakes

    Data.gov (United States)

    U.S. Environmental Protection Agency — Compilation of literature-reported intake values of phthalates; specifically dibutyl phthalate (DBP), bis(2-ethylhexyl) phthalate, and diisononyl phthalate (DiNP)....

  8. Di-n-butyl Phthalate (DNBP) and Diisobutyl Phthalate (DiBP) Metabolism in a Human Volunteer after Single Oral Doses [Journal Article

    Science.gov (United States)

    An individual (male, 36 years, 87 kg) ingested two separate doses of di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP) at a rate of ~60 µg/kg. Key monoester and oxidized metabolites were identified and quantified in urine continuously collected until 48 hours post dos...

  9. The role of impurities on the process of growing potassium hydrogen phthalate crystals from solution; A quantitative approach

    Science.gov (United States)

    Hottenhuis, M. H. J.; Lucasius, C. B.

    1988-09-01

    Quantitative information about the influence of impurities on the crystal growth process of potassium hydrogen phthalate from its aqueous solution was obtained at two levels: microscopic and macroscopic. At the microscopic level, detailed in situ observations of spiral steps at the (010) face were performed. The velocity of these steps was measured, as well in a "clean" as in a contaminated solution, where the influence of a number of different impurities was investigated. This resulted in a measure of effectiveness of step retardation for each of these impurities. From the same microscopic observations it was observed how these effectiveness factors were influenced by the supersaturation σ, the saturation temperature Ts of the solution and the concentration cimp of the impurity that w as used. At the macroscopic level, ICP (inductively coupled plasma) measurements were carried out in order to determine the distribution coefficient of the same impurities. In these measurements again the influence of the impurity concentration and the supersaturation on the distribution coefficient kD was determined.

  10. Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, B.; Mohan, R. [Preidency College, Bangalore (India); Raj, S. Gokul [RR and Dr. SR Technical Univ., Avadi (India); Kumar, G. Ramesh [Anna Univ., Arni (India)

    2012-11-15

    Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate C{sub 16} H{sub 12} K Li{sub 3} O{sub 11} belongs to triclinic system with the following unit-cell dimensions at 298(2) K; a = 7.405(5) A; b = 9.878(5) A; c = 13.396(5) A; α = 71.778(5) .deg.; β = 87.300(5) .deg.; γ = 85.405(5) .deg.; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated.

  11. Hydrogen Annealing Of Single-Crystal Superalloys

    Science.gov (United States)

    Smialek, James L.; Schaeffer, John C.; Murphy, Wendy

    1995-01-01

    Annealing at temperature equal to or greater than 2,200 degrees F in atmosphere of hydrogen found to increase ability of single-crystal superalloys to resist oxidation when subsequently exposed to oxidizing atmospheres at temperatures almost as high. Supperalloys in question are principal constituents of hot-stage airfoils (blades) in aircraft and ground-based turbine engines; also used in other high-temperature applications like chemical-processing plants, coal-gasification plants, petrochemical refineries, and boilers. Hydrogen anneal provides resistance to oxidation without decreasing fatigue strength and without need for coating or reactive sulfur-gettering constituents. In comparison with coating, hydrogen annealing costs less. Benefits extend to stainless steels, nickel/chromium, and nickel-base alloys, subject to same scale-adhesion and oxidation-resistance considerations, except that scale is chromia instead of alumina.

  12. Growth, optical, ICP and thermal studies of nonlinear optical single crystal: Sodium acid phthalate (NaAP)

    Science.gov (United States)

    Mahadevan, M.; Arivanandhan, M.; Elangovan, K.; Anandan, P.; Ramachandran, K.

    2017-07-01

    Good quality single crystals of sodium acid phthalate (NaAP) were grown by slow evaporation technique. Single crystal X-ray diffraction study of the grown crystal reveals that the crystal belongs to orthorhombic system with space group B2ab. Fourier transform infrared spectrum confirms the presence of the functional groups of the grown material. Inductively coupled plasma emission spectroscopy analysis is used to confirm the presence of Na element in the sample. Thermal analysis of the NaAP crystal shows that the crystal is stable up to 140°C. Optical transmittance of the grown crystal was recorded in the wavelength range from 200 and 800 nm using UV-Vis-NIR spectrophotometer. The second harmonic generation of NaAP was analysed using Kurtz powder technique.

  13. Phthalate Puzzle

    Indian Academy of Sciences (India)

    Abstract. The most common plasticizer, phthalates, are facing stricterregulations due to their omnipresence and possible effects onhuman health, and environment. But high cost, lack of applicationrange, and unknown long-term effects of non-phthalatealternatives make the scenario puzzling.

  14. Phthalate Puzzle

    Indian Academy of Sciences (India)

    difficulties in working with it and thereby limited its applicability. Plasticized PVC, a ... performance rather than physical properties as its incorporation increases ... Adult women had higher levels of urinary metabolites than men as phthalates ...

  15. EPR and optical absorption studies of paramagnetic molecular ion (VO2+) in Lithium Sodium Acid Phthalate single crystal

    Science.gov (United States)

    Subbulakshmi, N.; Kumar, M. Saravana; Sheela, K. Juliet; Krishnan, S. Radha; Shanmugam, V. M.; Subramanian, P.

    2017-12-01

    Electron Paramagnetic Resonance (EPR) spectroscopic studies of VO2+ ions as paramagnetic impurity in Lithium Sodium Acid Phthalate (LiNaP) single crystal have been done at room temperature on X-Band microwave frequency. The lattice parameter values are obtained for the chosen system from Single crystal X-ray diffraction study. Among the number of hyperfine lines in the EPR spectra only two sets are reported from EPR data. The principal values of g and A tensors are evaluated for the two different VO2+ sites I and II. They possess the crystalline field around the VO2+ as orthorhombic. Site II VO2+ ion is identified as substitutional in place of Na1 location and the other site I is identified as interstitial location. For both sites in LiNaP, VO2+ are identified in octahedral coordination with tetragonal distortion as seen from the spin Hamiltonian parameter values. The ground state of vanadyl ion in the LiNaP single crystal is dxy. Using optical absorption data the octahedral and tetragonal parameters are calculated. By correlating EPR and optical data, the molecular orbital bonding parameters have been discussed for both sites.

  16. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, Winfried, E-mail: kessler@helmholtz-muenchen.de [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Numtip, Wanwiwa [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Völkel, Wolfgang; Seckin, Elcim [Department of Chemical Safety and Toxicology, Bavarian Health and Food Safety Authority, Pfarrstrasse 3, D-80538 München (Germany); Csanády, György A. [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Institut für Toxikologie und Umwelthygiene, Technische Universität München, München (Germany); Pütz, Christian [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  17. Hydrogen adsorption on N-decorated single wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, Eduardo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Ruiz-Chavarria, Gregorio [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Departamento de Fisica, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico Ciudad Universitaria, Codigo Postal 04510, Mexico D.F. (Mexico); Magana, L.F., E-mail: fernando@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Arellano, J.S. [Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana, Unidad Azcapotzalco. Avenida San Pablo No. 180, Col. Reynosa Tamaulipas Codigo Postal 02200, Mexico D.F. (Mexico)

    2009-07-06

    Using density functional theory and molecular dynamics we found that N-decorated single walled (8,0) carbon nanotubes are potential high capacity hydrogen storage media. This system could store up to 6.0 wt% hydrogen at 300 K and ambient pressure, with average adsorption energy of -80 meV/(H{sub 2}). Nitrogen coverage was C{sub 8}N.

  18. Hydrogen adsorption on N-decorated single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Rangel, Eduardo; Ruiz-Chavarria, Gregorio; Magana, L.F.; Arellano, J.S.

    2009-01-01

    Using density functional theory and molecular dynamics we found that N-decorated single walled (8,0) carbon nanotubes are potential high capacity hydrogen storage media. This system could store up to 6.0 wt% hydrogen at 300 K and ambient pressure, with average adsorption energy of -80 meV/(H 2 ). Nitrogen coverage was C 8 N.

  19. Chemical reaction between single hydrogen atom and graphene

    International Nuclear Information System (INIS)

    Ito, Atsushi; Nakamura, Hiroaki; Takayama, Arimichi

    2007-04-01

    We study chemical reaction between a single hydrogen atom and a graphene, which is the elemental reaction between hydrogen and graphitic carbon materials. In the present work, classical molecular dynamics simulation is used with modified Brenner's empirical bond order potential. The three reactions, that is, absorption reaction, reflection reaction and penetration reaction, are observed in our simulation. Reaction rates depend on the incident energy of the hydrogen atom and the graphene temperature. The dependence can be explained by the following mechanisms: (1) The hydrogen atom receives repulsive force by π-electrons in addition to nuclear repulsion. (2) Absorbing the hydrogen atom, the graphene transforms its structure to the 'overhand' configuration such as sp 3 state. (3) The hexagonal hole of the graphene is expanded during the penetration of the hydrogen atom. (author)

  20. Separation of hydrogen isotopes via single column pressure swing adsorption

    International Nuclear Information System (INIS)

    Wong, Y.W.; Hill, F.B.

    1981-01-01

    Separation of hydrogen isotopes based on kinetic isotope effects was studied. The mixture separated was hydrogen containing a trace of tritium as HT and the hydride was vanadium monohydride. The separation was achieved using the single-column pressure swing process. Stage separation factors are larger and product cuts smaller than for a two-column pressure swing process operated in the same monohydride phase

  1. Prenatal exposure to an environmentally relevant phthalate mixture disrupts reproduction in F1 female mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Changqing; Gao, Liying; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2017-03-01

    Phthalates are used in a large variety of products, such as building materials, medical devices, and personal care products. Most previous studies on the toxicity of phthalates have focused on single phthalates, but it is also important to study the effects of phthalate mixtures because humans are exposed to phthalate mixtures. Thus, we tested the hypothesis that prenatal exposure to an environmentally relevant phthalate mixture adversely affects female reproduction in mice. To test this hypothesis, pregnant CD-1 dams were orally dosed with vehicle (tocopherol-stripped corn oil) or a phthalate mixture (20 and 200 μg/kg/day, 200 and 500 mg/kg/day) daily from gestational day 10 to birth. The mixture was based on the composition of phthalates detected in urine samples from pregnant women in Illinois. The mixture included 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. Female mice born to the exposed dams were subjected to tissue collections and fertility tests at different ages. Our results indicate that prenatal exposure to the phthalate mixture significantly increased uterine weight and decreased anogenital distance on postnatal days 8 and 60, induced cystic ovaries at 13 months, disrupted estrous cyclicity, reduced fertility-related indices, and caused some breeding complications at 3, 6, and 9 months of age. Collectively, our data suggest that prenatal exposure to an environmentally relevant phthalate mixture disrupts aspects of female reproduction in mice. - Highlights: • Prenatal exposure to a phthalate mixture disrupts F1 estrous cyclicity. • Prenatal exposure to a phthalate mixture induces F1 ovarian cysts. • Prenatal exposure to a phthalate mixture decreases F1 female fertility-related indices. • Prenatal exposure to a phthalate mixture induces F1 breeding complications.

  2. Growth features of ammonium hydrogen d-tartrate single crystals

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Ammonium hydrogen d-tartrate (d-AHT) single crystals were grown in silica gel. The growth fea- ... solution (specific gravity, 1⋅04 g/cc) with d-tartaric acid solution having ... resulting in the production of crystal nuclei. The interface.

  3. Modification of single wall carbon nanotubes (SWNT) for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Rashidi, A.M.; Nouralishahi, A.; Karimi, A.; Kashefi, K. [Nanotechnology Research Center, Research Institute of petroleum industry (RIPI), Tehran (Iran); Khodadadi, A.A.; Mortazavi, Y. [Chemical engineering Department, University of Tehran, Tehran (Iran)

    2010-09-15

    Due to unique structural, mechanical and electrical properties of single wall carbon nanotubes, SWNTs, they have been proposed as promising hydrogen storage materials especially in automotive industries. This research deals with investing of CNT's and some activated carbons hydrogen storage capacity. The CNT's were prepared through natural gas decomposition at a temperature of 900 C over cobalt-molybdenum nanoparticles supported by nanoporous magnesium oxide (Co-Mo/MgO) during a chemical vapor deposition (CVD) process. The effects of purity of CNT (80-95%wt.) on hydrogen storage were investigated here. The results showed an improvement in the hydrogen adsorption capacity with increasing the purity of CNT's. Maximum adsorption capacity was 0.8%wt. in case of CNT's with 95% purity and it may be raised up with some purification to 1%wt. which was far less than the target specified by DOE (6.5%wt.). Also some activated carbons were manufactured and the results compared to CNTs. There were no considerable H{sub 2}-storage for carbon nanotubes and activated carbons at room-temperature due to insufficient binding between H{sub 2} molecules carbon nanostructures. Therefore, hydrogen must be adsorbed via interaction of atomic hydrogen with the storage environment in order to achieve DOE target, because the H atoms have a very stronger interaction with carbon nanostructures. (author)

  4. Mitochondrial toxicity of phthalate esters.

    OpenAIRE

    Melnick, R L; Schiller, C M

    1982-01-01

    The effects of mono- and dibutyl phthalate and mono- and di(2-ethylhexyl) phthalate on energy-dependent K+ uptake, respiration rates, and succinate cytochrome c reductase activities of isolated rat liver mitochondria were evaluated. The energy-coupling processes, active K+ transport and oxidative phosphorylation, were affected most by di-n-butyl phthalate and mono(2-ethylhexyl) phthalate. Mono-n-butyl phthalate had a moderate effect on energy coupling and di(2-ethylhexyl) phthalate had no app...

  5. Phthalates biodegradation in the environment.

    Science.gov (United States)

    Liang, Da-Wei; Zhang, Tong; Fang, Herbert H P; He, Jianzhong

    2008-08-01

    Phthalates are synthesized in massive amounts to produce various plastics and have become widespread in environments following their release as a result of extensive usage and production. This has been of an environmental concern because phthalates are hepatotoxic, teratogenic, and carcinogenic by nature. Numerous studies indicated that phthalates can be degraded by bacteria and fungi under aerobic, anoxic, and anaerobic conditions. This paper gives a review on the biodegradation of phthalates and includes the following aspects: (1) the relationship between the chemical structure of phthalates and their biodegradability, (2) the biodegradation of phthalates by pure/mixed cultures, (3) the biodegradation of phthalates under various environments, and (4) the biodegradation pathways of phthalates.

  6. Modeling the adsorption of hydrogen, sodium, chloride and phthalate on goethite using a strict charge-neutral ion-exchange theory.

    Science.gov (United States)

    Schulthess, Cristian P; Ndu, Udonna

    2017-01-01

    Simultaneous adsorption modeling of four ions was predicted with a strict net charge-neutral ion-exchange theory and its corresponding equilibrium and mass balance equations. An important key to the success of this approach was the proper collection of all the data, particularly the proton adsorption data, and the inclusion of variable concentrations of conjugate ions from the experimental pH adjustments. Using IExFit software, the ion-exchange model used here predicted the competitive retention of several ions on goethite by assuming that the co-adsorption or desorption of all ions occurred in the correct stoichiometries needed to maintain electroneutrality. This approach also revealed that the retention strength of Cl- ions on goethite increases in the presence of phthalate ions. That is, an anion-anion enhancement effect was observed. The retention of Cl- ions was much weaker than phthalate ions, and this also resulted in a higher sensitivity of the Cl- ions toward minor variations in the surface reactivity. The proposed model uses four goethite surface sites. The drop in retention of phthalate ions at low pH was fully described here as resulting from competitive Cl- reactions, which were introduced in increasing concentrations into the matrix as the conjugate base to the acid added to lower the pH.

  7. Single pressure vessel (SPV) nickel-hydrogen battery design

    Energy Technology Data Exchange (ETDEWEB)

    Coates, D.; Grindstaff, B.; Fox, C. [Eagle-Picher Industries, Inc., Joplin, MO (United States)

    1995-07-01

    Single pressure vessel (SPV) technology combines an entire multi-cell nickel-hydrogen (NiH{sub 2}) space battery within a single pressure vessel. SPV technology has been developed to improve the performance (volume/mass) of the NiH{sub 2} system at the battery level and ultimately to reduce overall battery cost and increase system reliability. Three distinct SPV technologies are currently under development and in production. Eagle-Picher has license to the COMSAT Laboratories technology, as well as internally developed independent SPV technology. A third technology resulted from the acquisition of Johnson Controls NiH{sub 2} battery assets in June, 1994. SPV batteries are currently being produced in 25 ampere-hour (Ah), 35 Ah and 50 Ah configurations. The battery designs have an overall outside diameter of 10 inches (25.4 centimeters).

  8. Phthalate esters in marine algae

    OpenAIRE

    Gezgin, Tuncay; Güven, Kasim Cemal; Akçin, Göksel

    2001-01-01

    Abstract o-Phthalate esters as diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and diethylhexyl phthalate were identified at surface and inner part of algae collected in the Bosphorus, as Ulva lactuca, Enteromorpha linza, Cystoseria barbata, Pterocladia capillaceaeand Ceramium rubrum. The same esters were also detected in seawater samples taken from the same area. Thus parallelism in pollution was noted between the algae and the surrounding seawater,

  9. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...... phthalates, but our knowledge about metabolic distribution in the body and other biological fluids, including breast milk, is limited. Compared to urine, human breast milk contains relatively more of the hydrophobic phthalates, such as di-n-butyl phthalate and the longer-branched, di(2-ethylhexyl) phthalate...... (DEHP) and di-iso-nonyl phthalate (DiNP); and their monoester metabolites. Urine, however, contains relatively more of the secondary metabolites of DEHP and DiNP, as well as the monoester phthalates of the more short-branched phthalates. This differential distribution is of special concern as...

  10. Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

    OpenAIRE

    Seed, J L

    1982-01-01

    The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

  11. The effect of atomic hydrogen adsorption on single-walled carbon nano tubes properties

    International Nuclear Information System (INIS)

    Jalili, S.; Majidi, R.

    2007-01-01

    We investigated the adsorption of hydrogen atoms on metallic single-walled carbon nano tubes using ab initio molecular dynamics method. It was found that the geometric structures and the electronic properties of hydrogenated SWNTs can be strongly changed by varying hydrogen coverage. The circular cross sections of the CNTs were changed with different hydrogen coverage. When hydrogen is chemisorbed on the surface of the carbon nano tube, the energy gap will be appeared. This is due to the degree of the Sp 3 hybridization, and the hydrogen coverage can control the band gap of the carbon nano tube

  12. Miniaturized and green method for determination of chemical oxygen demand using UV-induced oxidation with hydrogen peroxide and single drop microextraction

    International Nuclear Information System (INIS)

    Akhoundzadeh, Jeyran; Chamsaz, Mahmoud; Costas, Marta; Lavilla, Isela; Bendicho, Carlos

    2013-01-01

    We report on a green method for the determination of low levels of chemical oxygen demand. It is based on the combination of (a) UV-induced oxidation with hydrogen peroxide, (b) headspace single-drop microextraction with in-drop precipitation, and (c) micro-turbidimetry. The generation of CO 2 after photolytic oxidation followed by its sequestration onto a microdrop of barium hydroxide gives rise to a precipitate of barium carbonate which is quantified by turbidimetry. UV-light induced oxidation was studied in the absence and presence of H 2 O 2 , ultrasound, and ferrous ion. Determinations of chemical oxygen demand were performed using potassium hydrogen phthalate as a model compound. The optimized method gives a calibration curve that is linear between 3.4 and 20 mg L −1 oxygen. The detection limit was 1.2 mg L −1 of oxygen, and the repeatability (as relative standard deviation) was around 5 %. The method was successfully applied to the determination of chemical oxygen demand in different natural waters and a synthetic wastewater. (author)

  13. 75 FR 67692 - Notice of Teleconference of the Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2010-11-03

    ... on Phthalates and Phthalate Substitutes AGENCY: Consumer Product Safety Commission. ACTION: Notice of... teleconference of the Chronic Hazard Advisory Panel (CHAP) on phthalates and phthalate substitutes. The Commission appointed this CHAP to study the effects on children's health of all phthalates and phthalate...

  14. Phthalate exposure and childhood obesity

    Directory of Open Access Journals (Sweden)

    Shin Hye Kim

    2014-06-01

    Full Text Available Phthalates are commonly used as plasticizers and vehicles for cosmetic ingredients. Phthalate metabolites have documented biochemical activity including activating peroxisome proliferator-activated receptor and antiandrogenic effects, which may contribute to the development of obesity. In vitro and in vivo studies suggest that phthalates have significant effects on the development of obesity, especially after prenatal exposure at low doses. Although few studies have examined the effects of phthalate on obesity development in humans, some work has shown that phthalates affect humans and animals similarly. In this paper, we review the possible mechanisms of phthalate-induced obesity, and discuss evidence supporting the role of phthalates in the development of obesity in humans.

  15. Transplacental transfer of monomethyl phthalate and mono(2-ethylhexyl) phthalate in a human placenta perfusion system

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E; Hedegaard, Morten

    2007-01-01

    The transplacental passage of monomethylphtalate (mMP) and mono (2-ethylhexyl) phthalate (mEHP) was studied using an ex vivo placental perfusion model with simultaneous perfusion of fetal and maternal circulation in a single cotyledon. Umbilical cord blood and placental tissue collected both before...... plasma samples. mMP and possibly other short-chained phthalate monoesters in maternal blood can cross the placenta by slow transfer, whereas the results indicate no placental transfer of mEHP. Further studies are recommended....

  16. Assessment of fetal testis function and postnatal development of the male rat following in utero exposure to diethylhexyl phthalate, dipentyl phthalate, diisobutyl phthalate, diisoheptyl phthalate and diisononyl phthalate

    Science.gov (United States)

    Phthalate esters are a large class of plasticizer compounds widely used in many consumer product applications. Some phthalates induce male fetal endocrine toxicity and reproductive malformations through disruption of hormone production during sexual differentiation. Regulatory ag...

  17. Biphasic single-reactor process for dehydration of xylose and hydrogenation of produced furfural

    NARCIS (Netherlands)

    Ordomskiy, V.; Schouten, J.C.; Schaaf, van der J.; Nijhuis, T.A.

    2013-01-01

    The processes of xylose dehydration and the consecutive furfural hydrogenation have been combined in a single biphasic reactor. The dehydration was studied over Amberlyst-15 and the hydrogenation over a hydrophobic Ru/C catalyst. 1-Butanol, 2-methyltetrahydrofuran and cyclohexane were used as

  18. Light hydrogen isotopes in the single - walled carbon nano tube

    International Nuclear Information System (INIS)

    Khugaev, A.V.; Sultanov, R.A.; Guster, D.

    2007-01-01

    Full text: Progress of our understanding of the molecular hydrogen behavior in the nano tube interior open an intriguing possibility for the applications of these knowledge's to the solution of the hydrogen storage problem and light isotopes gas selectivity. That can strongly change the situation at the energy production in the world and completely change our civil life. These investigations underline the influence of the quantum effects on the properties of molecular hydrogen in the nano tube interior and it leads to the pure quantum-mechanical reformulation of the problem for the hydrogen behavior inside carbon nano tube as a problem of molecular quantum system behavior in the external field induced by the regular nano tube surface. In the present paper the molecular hydrogen behavior in the carbon nano tube was considered in the simple quantum mechanical manner. The main attention was paid to the investigation of the quantum sieving selectivity in the dependence of nano tube composition, radius and symmetry properties. For the interaction potential between hydrogen and nano tube surface was taken some phenomenological LJ(12,6) - (Lennard - Jones) potential and the external field induced by the nano tube in its interior is considered as a simple sum over the all nano tube carbon atoms. Influence of the structure of rotation (vibration) spectrum of the energy levels of diatomic molecules, such as H 2 , HD and D 2 on the final results and finite size of the nano tube along the axis of symmetry, its boundary effects is discussed in details. Thermal oscillations of nano tube surface were considered separately in the dependence of the temperature gradient along of the axis of symmetry

  19. Urinary phthalates from 168 girls and boys measured twice a year during a 5-year period

    DEFF Research Database (Denmark)

    Mouritsen, A; Frederiksen, H; Sørensen, K

    2013-01-01

    Background: Little is known about the possible deleterious effects of phthalate exposure on endogenous sex steroid levels in children. Objective: Our objective was to investigate whether urinary phthalate metabolite levels are associated with circulating adrenal androgen levels and age at puberty....... Methods: This was a longitudinal study of 168 healthy children (84 girls) examined every 6 months for 5 years. Serum levels of dehydroepiandrostenedione sulfate (DHEAS), Δ4-androstenedione, testosterone, and urinary morning excretion of 14 phthalate metabolites, corresponding to 7 different phthalate...... diesters were determined. A variation in urinary excretion of phthalates was evident in each child, which made a mean of repetitive samples more representative for long-term excretion than a single determination. Results: We found that girls with excretion of monobutyl phthalate isomers (MBP) and di(2...

  20. Cumulative exposure to phthalates from phthalate-containing drug products

    DEFF Research Database (Denmark)

    Ennis, Zandra Nymand; Broe, Anne; Pottegård, Anton

    2018-01-01

    European regulatory limit of exposure ranging between 380-1710 mg/year throughout the study period. Lithium-products constituted the majority of dibutyl phthalate exposure. Diethyl phthalate exposure, mainly caused by erythromycin, theophylline and diclofenac products, did not exceed the EMA regulatory...... to quantify annual cumulated phthalate exposure from drug products among users of phthalate-containing oral medications in Denmark throughout the period of 2004-2016. METHODS: We conducted a Danish nationwide cohort study using The Danish National Prescription Registry and an internal database held...

  1. Phthalates in toys available in Indian market.

    Science.gov (United States)

    Johnson, Sapna; Saikia, Nirmali; Sahu, Ramakant

    2011-06-01

    Twenty four children's toys and child care articles available in the local market of India were analyzed for eight phthalates as children toys are plasticized with phthalates. All toy samples showed the presence of one or more phthalates including di-(2-ethylhexyl) phthalate (96% of the samples), di-iso-nonyl phthalate and di-iso-decyl phthalate (42% of the samples) at a concentration ranging from 0.1% to 16.2%. Soft toys contain higher levels of phthalates as compared to hard toys as primary function of phthalates is softening of hard plastic materiel.

  2. Urinary phthalate metabolites and male reproductive function parameters in Chongqing general population, China.

    Science.gov (United States)

    Han, Xue; Cui, Zhihong; Zhou, Niya; Ma, Mingfu; Li, Lianbing; Li, Yafei; Lin, Hui; Ao, Lin; Shu, Weiqun; Liu, Jinyi; Cao, Jia

    2014-03-01

    This study was designed to investigate the phthalates exposure levels in general population in Chongqing City of China, and to determine the possible associations between phthalate exposure and male reproductive function parameters. We recruited 232 general men through Chongqing Family Planning Research Institute and Reproductive Center of Chongqing. In a single spot urine sample from each man, phthalate metabolites, including mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), mono-(2-ethylhexyl) phthalate (MEHP), mono-benzyl phthalate (MBzP), phthalic acid (PA), and total PA were analyzed using solid phase extraction and coupled with high-performance liquid chromatography and detection by tandem mass spectrometry. Semen parameters were dichotomized based on World Health Organization reference values. Sperm DNA damage were analyzed using the alkaline single-cell gel electrophoresis assay. Reproductive hormones were determined in serum by the radioimmunoassay kit. We observed a weak association between urinary MBP concentration and sperm concentration in Chongqing general population. MBP levels above the median were 1.97 times (95% confidence interval [CI] 0.97-4.04) more likely to have sperm concentration below the reference value. There were no other associations between phthalate metabolites and reproductive function parameters after adjusted for potential risk factors. Our study suggested that general population in Chongqing area of China exposure to the environmental level of phthalate have weak or without adverse effects on the reproduction. Copyright © 2013 Elsevier GmbH. All rights reserved.

  3. Single step fabrication method of fullerene/TiO2 composite photocatalyst for hydrogen production

    International Nuclear Information System (INIS)

    Kum, Jong Min; Cho, Sung Oh

    2011-01-01

    Hydrogen is one of the most promising alternative energy sources. Fossil fuel, which is the most widely used energy source, has two defects. One is CO 2 emission causing global warming. The other is exhaustion. On the other hand, hydrogen emits no CO 2 and can be produced by splitting water which is renewable and easily obtainable source. However, about 95% of hydrogen is derived from fossil fuel. It limits the merits of hydrogen. Hydrogen from fossil fuel is not a renewable energy anymore. To maximize the merits of hydrogen, renewability and no CO 2 emission, unconventional hydrogen production methods without using fossil fuel are required. Photocatalytic water-splitting is one of the unconventional hydrogen production methods. Photocatalytic water-splitting that uses hole/electron pairs of semiconductor is expectable way to produce clean and renewable hydrogen from solar energy. TiO 2 is the semiconductor material which has been most widely used as photocatalyst. TiO 2 shows high photocatalytic reactivity and stability in water. However, its wide band gap only absorbs UV light which is only 5% of sun light. To enhance the visible light responsibility, composition with fullerene based materials has been investigated. 1-2 Methano-fullerene carboxylic acid (FCA) is one of the fullerene based materials. We tried to fabricate FCA/TiO 2 composite using UV assisted single step method. The method not only simplified the fabrication procedures, but enhanced hydrogen production rate

  4. Preparation of Ag@mSiO{sub 2} and Pt@mSiO{sub 2}nano composites using trioctylmethyl ammonium hydrogen phthalate (TOMAHP) ionic liquid as reaction medium

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Sujoy, E-mail: sujoyb@barc.gov.in [Chemical Engineering Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dasgupta, Kinshuk [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bahadur, Jitendra [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tewari, Raghavendra [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mazumder, Subhasish [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-09-15

    A novel one step green chemistry approach utilizing trioctylmethyl ammonium hydrogen phthalate (TOMAHP), task specific ionic liquid has been attempted for synthesis of Ag and Pt nanoparticles supported on silica (Ag@mSiO{sub 2} and Pt@mSiO{sub 2}). Structure, size distribution and morphology of these nano-composite particles were evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), small angle neutron scattering (SANS) as well as small angle X-ray scattering (SAXS) techniques. The XRD results show that Ag/Pt metal nanoparticles deposited on to SiO{sub 2} surface are face center cubic (fcc) in nature. The TEM and SAXS/SANS results show the morphology and size distributions of Ag and Pt nanoparticles loaded on to the surface of SiO{sub 2}. It has been found that Ag nanoparticles are well dispersed on to the SiO{sub 2} surface and are quite monodisperse in size, whereas Pt nanoparticles are quite polydisperse in size and forms aggregate or chain like structure on SiO{sub 2} surface containing primary nanoparticles of typical size range 3–7 nm. The stability of nanoparticles, which controls its dispersion on SiO{sub 2} substrate, has been discussed. - Graphical abstract: Mechanism for Ag@mSiO{sub 2} and Pt@mSiO{sub 2} nano composites in TOMAHP ionic liquid medium. - Highlights: • Novel methods for preparation of Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite in functionalized ionic liquid. • Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite are characterized using XRD, TEM as well as small angle x-ray scattering techniques. • The sizes of nano composite is <10 nm in size. • The method is simple one step, green chemical reduction method to prepare SiO{sub 2} support nano catalyst.

  5. Cloning single wall carbon nanotubes for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Tour, James M [Rice Univ., Houston, TX (United States); Kittrell, Carter [Rice Univ., Houston, TX (United States)

    2012-08-30

    The purpose of this research is to development the technology required for producing 3-D nano-engineered frameworks for hydrogen storage based on sp2 carbon media, which will have high gravimetric and especially high volumetric uptake of hydrogen, and in an aligned fibrous array that will take advantage of the exceptionally high thermal conductivity of sp2 carbon materials to speed up the fueling process while minimizing or eliminating the need for internal cooling systems. A limitation for nearly all storage media using physisorption of the hydrogen molecule is the large amount of surface area (SA) occupied by each H2 molecule due to its large zero-point vibrational energy. This creates a conundrum that in order to maximize SA, the physisorption media is made more tenuous and the density is decreased, usually well below 1 kg/L, so that there comes a tradeoff between volumetric and gravimetric uptake. Our major goal was to develop a new type of media with high density H2 uptake, which favors volumetric storage and which, in turn, has the capability to meet the ultimate DoE H2 goals.

  6. Hydrogen positions in single nanocrystals revealed by electron diffraction

    Czech Academy of Sciences Publication Activity Database

    Palatinus, Lukáš; Brázda, Petr; Boullay, P.; Pérez, O.; Klementová, Mariana; Petit, S.; Eigner, Václav; Zaarour, M.; Mintova, S.

    2017-01-01

    Roč. 355, č. 6321 (2017), s. 166-169 ISSN 0036-8075 R&D Projects: GA ČR GA16-10035S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : hydrogen atoms * crystal structure * electron diffraction tomography * nanocrystalline materials Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 37.205, year: 2016

  7. Monte-Carlo Simulation of Hydrogen Adsorption in Single-Wall Carbon Nano-Cones

    Directory of Open Access Journals (Sweden)

    Zohreh Ahadi

    2011-01-01

    Full Text Available The properties of hydrogen adsorption in single-walled carbon nano-cones are investigated in detail by Monte Carlo simulations. A great deal of our computational results show that the hydrogen storage capacity in single-walled carbon nano-cones is slightly smaller than the capacity of single-walled carbon nanotubes at any time at the same conditions. This indicates that the hydrogen storage capacity of single-walled carbon nano-cones is related to angles of carbon nano-cones. It seems that these type of nanotubes could not exceed the 2010 goal of 6 wt%, which is presented by the U.S. Department of Energy. In addition, these results are discussed in theory.

  8. Phthalate excretion pattern and testicular function

    DEFF Research Database (Denmark)

    Joensen, Ulla Nordström; Frederiksen, Hanne; Jensen, Martin Blomberg

    2012-01-01

    In animals, some phthalates impair male reproductive development and function. Epidemiological studies have reported inconsistent evidence of associations between phthalates and markers of human testicular function.......In animals, some phthalates impair male reproductive development and function. Epidemiological studies have reported inconsistent evidence of associations between phthalates and markers of human testicular function....

  9. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...

  10. Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

    International Nuclear Information System (INIS)

    Oksengorn, B.

    2010-01-01

    A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

  11. Phthalates, Nonylphenols and LAS in Roskilde Wastewater Treatment Plant

    DEFF Research Database (Denmark)

    Fauser, P.; Sørensen, P. B.; Carlsen, L.

    , involving alternating degradation and flow conditions between two reactors, with one single biological reactor with continuos flow (SimpleTreat) has been investigated by setting-up two models representing the respective operation schemes. An experimental series was performed where inlet, outlet, primary...... sludge and secondary sludge samples were taken and analysed for phthalates, nonylphenols and LAS. Generally the modelled half-lives for the phthalates were low and the removal efficiencies of the nonylphenols and phthalates were high compared to literature values. The results from the modelling work...... concludes that it is possible to substitute a complex alternating operation with a system containing one single biological reactor, corresponding to SimpleTreat, when a suggested empirical aggregate 1st order degradation rate is employed...

  12. Evaluation of Fermentative Hydrogen Production from Single and Mixed Fruit Wastes

    Directory of Open Access Journals (Sweden)

    Julius Akinbomi

    2015-05-01

    Full Text Available The economic viability of employing dark fermentative hydrogen from whole fruit wastes as a green alternative to fossil fuels is limited by low hydrogen yield due to the inhibitory effect of some metabolites in the fermentation medium. In exploring means of increasing hydrogen production from fruit wastes, including orange, apple, banana, grape and melon, the present study assessed the hydrogen production potential of singly-fermented fruits as compared to the fermentation of mixed fruits. The fruit feedstock was subjected to varying hydraulic retention times (HRTs in a continuous fermentation process at 55 °C for 47 days. The weight distributions of the first, second and third fruit mixtures were 70%, 50% and 20% orange share, respectively, while the residual weight was shared equally by the other fruits. The results indicated that there was an improvement in cumulative hydrogen yield from all of the feedstock when the HRT was five days. Based on the results obtained, apple as a single fruit and a fruit mixture with 20% orange share have the most improved cumulative hydrogen yields of 504 (29.5% of theoretical yield and 513 mL/g volatile solid (VS (30% of theoretical yield , respectively, when compared to other fruits.

  13. Defect studies of ZnO single crystals electrochemically doped with hydrogen

    Science.gov (United States)

    Čížek, J.; Žaludová, N.; Vlach, M.; Daniš, S.; Kuriplach, J.; Procházka, I.; Brauer, G.; Anwand, W.; Grambole, D.; Skorupa, W.; Gemma, R.; Kirchheim, R.; Pundt, A.

    2008-03-01

    Various defect studies of hydrothermally grown (0001) oriented ZnO crystals electrochemically doped with hydrogen are presented. The hydrogen content in the crystals is determined by nuclear reaction analysis and it is found that already 0.3at.% H exists in chemically bound form in the virgin ZnO crystals. A single positron lifetime of 182ps is detected in the virgin crystals and attributed to saturated positron trapping at Zn vacancies surrounded by hydrogen atoms. It is demonstrated that a very high amount of hydrogen (up to ˜30at.%) can be introduced into the crystals by electrochemical doping. More than half of this amount is chemically bound, i.e., incorporated into the ZnO crystal lattice. This drastic increase of the hydrogen concentration is of marginal impact on the measured positron lifetime, whereas a contribution of positrons annihilated by electrons belonging to O-H bonds formed in the hydrogen doped crystal is found in coincidence Doppler broadening spectra. The formation of hexagonal shape pyramids on the surface of the hydrogen doped crystals by optical microscopy is observed and discussed.

  14. Single-site catalyst promoters accelerate metal-catalyzed nitroarene hydrogenation

    KAUST Repository

    Wang, Liang

    2018-04-04

    Atomically dispersed supported metal catalysts are drawing wide attention because of the opportunities they offer for new catalytic properties combined with efficient use of the metals. We extend this class of materials to catalysts that incorporate atomically dispersed metal atoms as promoters. The catalysts are used for the challenging nitroarene hydrogenation and found to have both high activity and selectivity. The promoters are single-site Sn on TiO2 supports that incorporate metal nanoparticle catalysts. Represented as M/Sn-TiO2 (M = Au, Ru, Pt, Ni), these catalysts decidedly outperform the unpromoted supported metals, even for hydrogenation of nitroarenes substituted with various reducible groups. The high activity and selectivity of these catalysts result from the creation of oxygen vacancies on the TiO2 surface by single-site Sn, which leads to efficient, selective activation of the nitro group coupled with a reaction involving hydrogen atoms activated on metal nanoparticles.

  15. Studies of isotopic defined hydrogen beams scattering from Pd single-crystal surfaces

    International Nuclear Information System (INIS)

    Varlam, Mihai; Steflea, Dumitru

    2001-01-01

    An experimental investigation of hydrogen isotopes interaction with Pd single-crystal surface has been carried out using molecular beam technique. The energy dependence of the sticking probability and its relation with the trapping probability into the precursor state is studied by integrating the scattered angular distribution of hydrogen Isotopic defined beams from Pd (111) surface in the 40-400 K surface temperature range. The dependence has been evaluated by defining hydrogen molecular beams with different isotopic concentration - from the natural one to the 5% D/(D+H) ratio - and for different incident energies. The beam was directed onto a single-crystal Pd (111) surface. In the paper, we report the experimental results and some considerations related to it. (authors)

  16. Studies of isotopic defined hydrogen beams scattering from Pd single-crystal surfaces

    International Nuclear Information System (INIS)

    Varlam, Mihai; Steflea, Dumitru

    1999-01-01

    An experimental investigation of hydrogen isotopes interaction with Pd single-crystal surfaces has been carried out using molecular beam technique. The energy dependence of the sticking probability and its relation with the trapping probability into the precursor state is studied by integrating the scattered angular distribution of hydrogen isotopic defined beams from Pd (111) surfaces in the 40 - 400 K surface temperature range. The dependence has been evaluated by defining hydrogen molecular beams with different isotopic concentration - from the natural one until 5% D/(D + H) and different incident energies and directed onto a single - crystal Pd (111) surface. In the paper, we report the experimental results and some considerations related to them. (authors)

  17. Single-site catalyst promoters accelerate metal-catalyzed nitroarene hydrogenation

    KAUST Repository

    Wang, Liang; Guan, Erjia; Zhang, Jian; Yang, Junhao; Zhu, Yihan; Han, Yu; Yang, Ming; Cen, Cheng; Fu, Gang; Gates, Bruce C.; Xiao, Feng-Shou

    2018-01-01

    Atomically dispersed supported metal catalysts are drawing wide attention because of the opportunities they offer for new catalytic properties combined with efficient use of the metals. We extend this class of materials to catalysts that incorporate atomically dispersed metal atoms as promoters. The catalysts are used for the challenging nitroarene hydrogenation and found to have both high activity and selectivity. The promoters are single-site Sn on TiO2 supports that incorporate metal nanoparticle catalysts. Represented as M/Sn-TiO2 (M = Au, Ru, Pt, Ni), these catalysts decidedly outperform the unpromoted supported metals, even for hydrogenation of nitroarenes substituted with various reducible groups. The high activity and selectivity of these catalysts result from the creation of oxygen vacancies on the TiO2 surface by single-site Sn, which leads to efficient, selective activation of the nitro group coupled with a reaction involving hydrogen atoms activated on metal nanoparticles.

  18. Migration of phthalates on culture plates

    DEFF Research Database (Denmark)

    Frohnert Hansen, Juliana; Boas, Malene; Møller Brorson, Marianne

    2016-01-01

    -well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8...... cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added...... to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion...

  19. How far can a single hydrogen bond tune the spectral properties of the GFP chromophore?

    DEFF Research Database (Denmark)

    Kiefer, Hjalte; Lattouf, Elie; Persen, Natascha Wardinghus

    2015-01-01

    Photoabsorption of the hydrogen-bonded complex of a neutral and an anionic Green Fluorescent Protein chromophore has been studied using a new dual-detection approach to action-absorption spectroscopy. Following absorption of one photon, dissociation through a single channel ensures that the full ...

  20. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes

    DEFF Research Database (Denmark)

    Pirrotta, Alessandro; De Vico, Luca; Solomon, Gemma C.

    2017-01-01

    to inform about molecular recognition events at the single-molecule limit. For this, we consider the force-conductance characteristics of a prototypical class of hydrogen bonded bimolecular complexes sandwiched between gold electrodes. The complexes consist of derivatives of a barbituric acid and a Hamilton...... is mechanically manipulated. The implication is that force and conductance provide complementary information about the evolution of molecules in junctions that can be used to interrogate basic structure-transport relations at the single-molecule limit....

  1. Introducing molecular selectivity in rapid impedimetric sensing of phthalates

    KAUST Repository

    Zia, Asif I.

    2014-05-01

    This research article reports a real-time and non-invasive detection technique for phthalates in liquids by Electrochemical Impedance Spectroscopy (EIS), incorporating molecular imprinting technique to introduce selectivity for the phthalate molecule in the detection system. A functional polymer with Bis (2-ethylhexyl) phthalate (DEHP) template was immobilized on the sensing surface of the inter-digital (ID) capacitive sensor with sputtered gold sensing electrodes fabricated over a native layer of silicon dioxide on a single crystal silicon substrate. Various concentrations (10 to 200 ppm) of DEHP in deionized MilliQ water were exposed to the sensor surface functionalized with molecular imprinted polymer (MIP) in order to capture the analyte molecule, hence introducing molecular selectivity to the testing system. Impedance spectra were obtained using EIS in order to determine sample conductance for evaluation of phthalate concentration in the solution. Electrochemical Spectrum Analyzer algorithm was used to deduce equivalent circuit and equivalent component parameters from the experimentally obtained impedance spectra employing Randle\\'s cell model curve fitting technique. Experimental results confirmed that the immobilization of the functional polymer on sensing surface introduces selectivity for phthalates in the sensing system. The results were validated by testing the samples using High Performance Liquid Chromatography (HPLC-DAD). © 2014 IEEE.

  2. 75 FR 36639 - Change in Times for Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2010-06-28

    ... Phthalates and Phthalate Substitutes and Correction of E-mail Address AGENCY: Consumer Product Safety... Hazard Advisory Panel (CHAP) on phthalates and phthalate substitutes. The Commission appointed this CHAP to study the effects on children's health of all phthalates and phthalate alternatives as used in...

  3. Possible phthalates transport into plants

    Directory of Open Access Journals (Sweden)

    Alžbeta Jarošová

    2010-01-01

    Full Text Available Soils can be contaminated by high concentrations of phthalic acid esters (PAE resulting from industrial and intensive agricultural activities. A plant receives water and substances (including pollutants from soil by means of rootage. Water solution received by the roots is distributed in particular by means of xylem. Reception by means of floem is not very considerable. Pollutants (including phthalates can be absorbed by roots either by diffusion by means of soil gas phase or soil liquid phase. Another possible way of pollutant entering into the plant is diffusion from atmosphere. Way of substance entering into the plant is decided by so called Henry constant as well as octanol-water partition coefficient. In case of phthalates, big differences between di-n-butyl phthalate (DBP reception and dioctyl phthalate reception were detected. For example, DBP can enter into the plant by means of gas as well as liquid phase while dioctyl phthalate only by gas phase.This publication summarizes fundamental knowledge on possible phthalates transport into plants.

  4. Phthalate Metabolites, Consumer Habits and Health Effects

    Directory of Open Access Journals (Sweden)

    Peter Wallner

    2016-07-01

    Full Text Available Phthalates are multifunctional chemicals used in a wide variety of consumer products. The aim of this study was to investigate whether levels of urinary phthalate metabolites in urine samples of Austrian mothers and their children were associated with consumer habits and health indicators. Within an Austrian biomonitoring survey, urine samples from 50 mother-child pairs of five communities (two-stage random stratified sampling were analysed. The concentrations of 14 phthalate metabolites were determined, and a questionnaire was administered. Monoethyl phthalate (MEP, mono-n-butyl phthalate (MnBP, mono-isobutyl phthalate (MiBP, monobenzyl phthalate (MBzP, mono-(2-ethylhexyl phthalate (MEHP, mono-(2-ethyl-5-hydroxyhexyl phthalate (5OH-MEHP, mono-(2-ethyl-5-oxohexyl phthalate (5oxo-MEHP, mono-(5-carboxy-2-ethylpentyl phthalate (5cx-MEPP, and 3-carboxy-mono-propyl phthalate (3cx-MPP could be quantified in the majority of samples. Significant correlations were found between the use of hair mousse, hair dye, makeup, chewing gum, polyethylene terephthalate (PET bottles and the diethyl phthalate (DEP metabolite MEP. With regard to health effects, significant associations of MEP in urine with headache, repeated coughing, diarrhoea, and hormonal problems were observed. MBzP was associated with repeated coughing and MEHP was associated with itching.

  5. Phthalate Metabolites, Consumer Habits and Health Effects.

    Science.gov (United States)

    Wallner, Peter; Kundi, Michael; Hohenblum, Philipp; Scharf, Sigrid; Hutter, Hans-Peter

    2016-07-15

    Phthalates are multifunctional chemicals used in a wide variety of consumer products. The aim of this study was to investigate whether levels of urinary phthalate metabolites in urine samples of Austrian mothers and their children were associated with consumer habits and health indicators. Within an Austrian biomonitoring survey, urine samples from 50 mother-child pairs of five communities (two-stage random stratified sampling) were analysed. The concentrations of 14 phthalate metabolites were determined, and a questionnaire was administered. Monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(5-carboxy-2-ethylpentyl) phthalate (5cx-MEPP), and 3-carboxy-mono-propyl phthalate (3cx-MPP) could be quantified in the majority of samples. Significant correlations were found between the use of hair mousse, hair dye, makeup, chewing gum, polyethylene terephthalate (PET) bottles and the diethyl phthalate (DEP) metabolite MEP. With regard to health effects, significant associations of MEP in urine with headache, repeated coughing, diarrhoea, and hormonal problems were observed. MBzP was associated with repeated coughing and MEHP was associated with itching.

  6. Hydrogen production with effluent from an ethanol–H2-coproducing fermentation reactor using a single-chamber microbial electrolysis cell

    KAUST Repository

    Lu, Lu; Ren, Nanqi; Xing, Defeng; Logan, Bruce E.

    2009-01-01

    Hydrogen can be produced by bacterial fermentation of sugars, but substrate conversion to hydrogen is incomplete. Using a single-chamber microbial electrolysis cell (MEC), we show that additional hydrogen can be produced from the effluent

  7. 76 FR 63610 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate Substitutes

    Science.gov (United States)

    2011-10-13

    ..., pregnant women, and other potentially susceptible individuals; and Consider possible similar health effects... Commission appointed this CHAP to study the effects on children's health of all phthalates and phthalate... Commission to convene a CHAP ``to study the effects on children's health of all phthalates and phthalate...

  8. 76 FR 13988 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate Substitutes

    Science.gov (United States)

    2011-03-15

    ..., and other potentially susceptible individuals; and Consider possible similar health effects of... Commission appointed this CHAP to study the effects on children's health of all phthalates and phthalate... convene a CHAP ``to study the effects on children's health of all phthalates and phthalate alternatives as...

  9. Endocrine disruption: In silico interactions between phthalate plasticizers and corticosteroid binding globulin.

    Science.gov (United States)

    Sheikh, Ishfaq A; Beg, Mohd A

    2017-12-01

    Endocrine disruption is a phenomenon when a man-made or natural compound interferes with normal hormone function in human or animal body systems. Endocrine-disrupting compounds (EDCs) have assumed considerable importance as a result of industrial activity, mass production of synthetic chemicals and environmental pollution. Phthalate plasticizers are a group of chemicals used widely and diversely in industry especially in the plastic industry, and many of the phthalate compounds have endocrine-disrupting properties. Increasing evidence indicates that steroid nuclear receptors and steroid binding proteins are the main targets of endocrine disruption. Corticosteroid-binding globulin (CBG) is a steroid binding protein that binds and transports cortisol in the blood circulation and is a potential target for endocrine disruption. An imbalance of cortisol in the body leads to many health problems. Induced fit docking of nine important and environmentally relevant phthalate plasticizers (DMP, BBP, DBP, DIBP, DnHP, DEHP, DINP, DnOP, DIDP) showed interactions with 10-19 amino acid residues of CBG. Comparison of the interacting residues of CBG with phthalate ligands and cortisol showed an overlapping of the majority (53-82%) of residues for each phthalate. Five of nine phthalate compounds and cortisol shared a hydrogen bonding interaction with the Arg-252 residue of CBG. Long-chain phthalates, such as DEHP, DINP, DnOP and DIDP displayed a higher binding affinity and formed a number of interactions with CBG in comparison to short-chain phthalates. The similarity in structural binding characteristics of phthalate compounds and native ligand cortisol suggested potential competitive conflicts in CBG-cortisol binding function and possible disruption of cortisol and progesterone homeostasis. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Single step vacuum-free and hydrogen-free synthesis of graphene

    Directory of Open Access Journals (Sweden)

    Christian Orellana

    2017-08-01

    Full Text Available We report a modified method to grow graphene in a single-step process. It is based on chemical vapor deposition and considers the use of methane under extremely adverse synthesis conditions, namely in an open chamber without requiring the addition of gaseous hydrogen in any of the synthesis stages. The synthesis occurs between two parallel Cu plates, heated up via electromagnetic induction. The inductive heating yields a strong thermal gradient between the catalytic substrates and the surrounding environment, promoting the enrichment of hydrogen generated as fragments of the methane molecules within the volume confined by the Cu foils. This induced density gradient is due to thermo-diffusion, also known as the Soret effect. Hydrogen and other low mass molecular fractions produced during the process inhibit oxidative effects and simultaneously reduce the native oxide on the Cu surface. As a result, high quality graphene is obtained on the inner surfaces of the Cu sheets as confirmed by Raman spectroscopy.

  11. Hydrogen storage in single-walled carbon nanotubes: methods and results

    International Nuclear Information System (INIS)

    Poirier, E.; Chahine, R.; Tessier, A.; Cossement, D.; Lafi, L.; Bose, T.K.

    2004-01-01

    We present high sensitivity gravimetric and volumetric hydrogen sorption measurement systems adapted for in situ conditioning under high temperature and high vacuum. These systems, which allow for precise measurements on small samples and thorough degassing, are used for sorption measurements on carbon nanostructures. We developed one volumetric system for the pressure range 0-1 bar, and two gravimetric systems for 0-1 bar and 0-100 bars. The use of both gravimetric and volumetric methods allows for the cross-checking of the results. The accuracy of the systems has been determined from hydrogen absorption measurements on palladium. The accuracies of the 0-1 bar volumetric and gravimetric systems are about 10 μg and 20 μg respectively. The accuracy of the 0-100 bars gravimetric system is about 20 μg. Hydrogen sorption measurements on single-walled carbon nanotubes (SWNTs) and metal-incorporated- SWNTs are presented. (author)

  12. Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

    International Nuclear Information System (INIS)

    Kuznetsov, G.F.

    2006-01-01

    Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

  13. A portable system powered with hydrogen and one single air-breathing PEM fuel cell

    International Nuclear Information System (INIS)

    Fernández-Moreno, J.; Guelbenzu, G.; Martín, A.J.; Folgado, M.A.; Ferreira-Aparicio, P.; Chaparro, A.M.

    2013-01-01

    Highlights: • A portable system based on hydrogen and single air breathing PEM fuel cell. • Control electronics designed for low single cell voltage (0.5–0.8 V). • Forced air convection and anode purging required to help water management. • Application consisting of a propeller able to display a luminous message. • Up to 20 h autonomy with continuous 1.1 W consumption, using 1 g H 2 . - Abstract: A portable system for power generation based on hydrogen and a single proton exchange membrane fuel cell (PEMFC) has been built and operated. The fuel cell is fed in the anode with hydrogen stored in a metal hydrides cartridge, and in the cathode with oxygen from quiescent ambient air (‘air breathing’). The control electronics of the system performs DC–DC conversion from the low voltage (0.5–0.8 V) and high current output (200–300 mA cm −2 ) of the single fuel cell, up to 3.3 V to power an electronic application. System components assist fuel cell operation, including an electronic valve for anode purging, a fan in front of the open cathode, two supercapacitors for auxiliary power requirements, four LED lights, and a display screen. The influence of the system components on fuel cell behaviour is analyzed. The cathode fan and anodic purging help excess water removal from the electrodes leading to steadier cell response at the expense of extra power consumption. The power system is able to provide above 1 W DC electricity to an external application during 20 h using 1 g of H 2 . An application consisting of a propeller able to display a luminous message is chosen to test system. It is shown that one single air breathing PEM fuel cell powered with hydrogen may provide high energy density and autonomy for portable applications

  14. Hydrogen adsorption on metal-organic frameworks (MOFs) and single-walled carbon nanotubes (SWNTs)

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, E.; Chahine, R.; Benard, P.; Lafi, L.; Dorval-Douville, G.; Chandonia, P.-A. [Univ. du Quebec a Trois-Rivieres, Inst. de recherche sur l' hydrogene, Trois-Rivieres, Quebec (Canada)]. E-mail: Lyubov.Lafi@uqtr.ca

    2006-07-01

    'Full text:' In recent years, several novel carbon-based microporous materials such as single-walled carbon nanotubes (SWNTs) and metal-organic frameworks (MOFs) have been proposed as promising adsorbents for hydrogen. Hydrogen adsorption measurements on Al-, Cr- and Zn-based metal-organic frameworks (MOFs) and single-walled carbon nanotubes (SWNTs) are presented. The measurements were performed at temperatures ranging from 77 to 300K and pressures up to 50 atm using a volumetric approach. The maximum excess adsorption at 77K ranges from 2,8 to 3,9 wt % for the MOFs and from 1,5 to 2,5 wt % for the SWNTs. These values are reached at pressures below 40 atm. At room temperature and 40 atm, modest amounts of hydrogen are adsorbed (< 0,4 wt %). A Dubinin-Astakhov (DA) approach is used to investigate the measured adsorption isotherms and retrieve energetic and structural parameters. The adsorption enthalpy averaged over filling is found to be about 2,9 kJ/mol for the MOF-5 and about 3,6 - 4,2 kJ/mol for SWNTs. The uptake of hydrogen on SWNTs and MOF-5 appears to be due to physisorption and can be described, through the DA-model, by a traditional theory of micropore filling. (author)

  15. Phthalates in baby skin care products.

    Science.gov (United States)

    Lampel, Heather P; Jacob, Sharon E

    2011-01-01

    The systemic toxicity of phthalates has been extensively reported. Although rarely sensitizing, phthalates have been implicated in promoting the development of both atopy and contact dermatitis in animal models. Dermal absorption of phthalates may contribute to overall chemical burden. Infants may be particularly susceptible to chemical exposures. Baby skin care products may be a significant source of phthalate exposure. We measured the phthalate content of 30 skin care products intended for babies and children. Nineteen leave-on and 11 wash-off baby skin care products were analyzed for 17 unique phthalates by an independent laboratory using standard gas chromatographic mass spectrometry. Of 30 products tested, four had phthalate levels above the reporting limit (0.1-0.5 ppm); of these, only one had levels above 1 ppm (44 ppm). There was no statistical significance of phthalate detection in leave-on versus wash-off products (p = .578). The majority (26 of 30) of the baby skin care products analyzed did not have detectable phthalate levels. Four products had detectable phthalate levels. In baby skin care products, levels of the 17 phthalates tested are low overall, but occasional products may contain higher phthalate levels. Monitoring products to ensure safety standards are met may be warranted.

  16. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport

    Directory of Open Access Journals (Sweden)

    Afrooz Farjoo

    2017-10-01

    Full Text Available Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene was studied within the temperature and pressure ranges of 25–600 °C and 110–160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption–diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  17. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport.

    Science.gov (United States)

    Farjoo, Afrooz; Kuznicki, Steve M; Sadrzadeh, Mohtada

    2017-10-06

    Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene) was studied within the temperature and pressure ranges of 25-600 °C and 110-160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption-diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  18. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes

    Science.gov (United States)

    Pirrotta, Alessandro; De Vico, Luca; Solomon, Gemma C.; Franco, Ignacio

    2017-03-01

    The emerging ability to study physical properties at the single-molecule limit highlights the disparity between what is observable in an ensemble of molecules and the heterogeneous contributions of its constituent parts. A particularly convenient platform for single-molecule studies are molecular junctions where forces and voltages can be applied to individual molecules, giving access to a series of electromechanical observables that can form the basis of highly discriminating multidimensional single-molecule spectroscopies. Here, we computationally examine the ability of force and conductance to inform about molecular recognition events at the single-molecule limit. For this, we consider the force-conductance characteristics of a prototypical class of hydrogen bonded bimolecular complexes sandwiched between gold electrodes. The complexes consist of derivatives of a barbituric acid and a Hamilton receptor that can form up to six simultaneous hydrogen bonds. The simulations combine classical molecular dynamics of the mechanical deformation of the junction with non-equilibrium Green's function computations of the electronic transport. As shown, in these complexes hydrogen bonds mediate transport either by directly participating as a possible transport pathway or by stabilizing molecular conformations with enhanced conductance properties. Further, we observe that force-conductance correlations can be very sensitive to small changes in the chemical structure of the complexes and provide detailed information about the behavior of single molecules that cannot be gleaned from either measurement alone. In fact, there are regions during the elongation that are only mechanically active, others that are only conductance active, and regions where both force and conductance changes as the complex is mechanically manipulated. The implication is that force and conductance provide complementary information about the evolution of molecules in junctions that can be used to

  19. Performance features of 22-cell, 19Ah single pressure vessel nickel hydrogen battery

    Energy Technology Data Exchange (ETDEWEB)

    Rao, G.M.; Vaidyanathan, H.

    1996-02-01

    Two 22-cells 19Ah Nickel-Hydrogen (Ni-H2) Single Pressure Vessel (SPV) Qual batteries, one each from EPI/Joplin and EPI/Butler, were designed and procured. The two batteries differ in the cell encapsulation technology, stack preload, and activation procedure. Both the Butler and Joplin batteries met the specified requirements when subjected to qualification testing and completed 2100 and 1300 LEO cycles respectively, with nominal performance. This paper discusses advantages, design features, testing procedures, and results of the two single pressure vessel Ni-H2 batteries.

  20. Performance features of 22-cell, 19Ah single pressure vessel nickel hydrogen battery

    Science.gov (United States)

    Rao, Gopalakrishna M.; Vaidyanathan, Hari

    1996-01-01

    Two 22-cells 19Ah Nickel-Hydrogen (Ni-H2) Single Pressure Vessel (SPV) Qual batteries, one each from EPI/Joplin and EPI/Butler, were designed and procured. The two batteries differ in the cell encapsulation technology, stack preload, and activation procedure. Both the Butler and Joplin batteries met the specified requirements when subjected to qualification testing and completed 2100 and 1300 LEO cycles respectively, with nominal performance. This paper discusses advantages, design features, testing procedures, and results of the two single pressure vessel Ni-H2 batteries.

  1. Associations between urinary phthalate concentrations and semen quality parameters in a general population

    Science.gov (United States)

    Bloom, M.S.; Whitcomb, B.W.; Chen, Z.; Ye, A.; Kannan, K.; Buck Louis, G.M.

    2015-01-01

    CAUTION While adverse associations were observed, the implications of the findings for couple fecundity and fertility remain to be established. Cautious interpretation is needed in light of reliance on a single measurement of phthalate measure and no correction for multiple comparisons. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (N01-HD-3-3355, N01-HD-3-3356 and NOH-HD-3-3358). The authors declare they have no actual or potential competing financial interests. PMID:26350610

  2. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    Energy Technology Data Exchange (ETDEWEB)

    Koetzle, Thomas F. [IPNS Division, Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: tkoetzle@anl.gov; Piccoli, Paula M.B.; Schultz, Arthur J. [IPNS Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2009-02-21

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a {beta}-diketone enol system with a very short, strong intramolecular O-H...O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS)

  3. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    Science.gov (United States)

    Koetzle, Thomas F.; Piccoli, Paula M. B.; Schultz, Arthur J.

    2009-02-01

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a β-diketone enol system with a very short, strong intramolecular O-H⋯O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS).

  4. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    International Nuclear Information System (INIS)

    Koetzle, Thomas F.; Piccoli, Paula M.B.; Schultz, Arthur J.

    2009-01-01

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a β-diketone enol system with a very short, strong intramolecular O-H...O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS).

  5. Hydrogen-related complexes in Li-diffused ZnO single crystals

    Science.gov (United States)

    Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

    2016-07-01

    Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>1019 cm-3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm-1, attributed to surface O-H species. When Li2CO3 is used, a structured blue luminescence band and O-H mode at 3327 cm-1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy-hydrogen complex, with an acceptor level ˜0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

  6. Hydrogen-related complexes in Li-diffused ZnO single crystals

    International Nuclear Information System (INIS)

    Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

    2016-01-01

    Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li_2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10"1"9" cm"−"3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm"−"1, attributed to surface O-H species. When Li_2CO_3 is used, a structured blue luminescence band and O-H mode at 3327 cm"−"1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

  7. Hydrogen-related complexes in Li-diffused ZnO single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Corolewski, Caleb D. [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Parmar, Narendra S.; Lynn, Kelvin G. [Center for Materials Research, Washington State University, Pullman, Washington 99164-2814 (United States); McCluskey, Matthew D., E-mail: mattmcc@wsu.edu [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

    2016-07-21

    Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li{sub 2}O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10{sup 19 }cm{sup −3}). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm{sup −1}, attributed to surface O-H species. When Li{sub 2}CO{sub 3} is used, a structured blue luminescence band and O-H mode at 3327 cm{sup −1} are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

  8. Hydrogen-induced structural transition in single layer ReS2

    Science.gov (United States)

    Yagmurcukardes, M.; Bacaksiz, C.; Senger, R. T.; Sahin, H.

    2017-09-01

    By performing density functional theory-based calculations, we investigate how structural, electronic and mechanical properties of single layer ReS2 can be tuned upon hydrogenation of its surfaces. It is found that a stable, fully hydrogenated structure can be obtained by formation of strong S-H bonds. The optimized atomic structure of ReS2H2 is considerably different than that of the monolayer ReS2 which has a distorted-1T phase. By performing phonon dispersion calculations, we also predict that the Re2-dimerized 1T structure (called 1T {{}\\text{R{{\\text{e}}2}}} ) of the ReS2H2 is dynamically stable. Unlike the bare ReS2 the 1T {{}\\text{R{{\\text{e}}2}}} -ReS2H2 structure which is formed by breaking the Re4 clusters into separated Re2 dimers, is an indirect-gap semiconductor. Furthermore, mechanical properties of the 1T {{}\\text{R{{\\text{e}}2}}} phase in terms of elastic constants, in-plane stiffness (C) and Poisson ratio (ν) are investigated. It is found that full hydrogenation not only enhances the flexibility of the single layer ReS2 crystal but also increases anisotropy of the elastic constants.

  9. Diisobutyl phthalate has comparable anti-androgenic effects to di-n-butyl phthalate in fetal rat testis

    DEFF Research Database (Denmark)

    Boberg, Julie; Petersen, Marta Axelstad; Vinggaard, Anne

    2006-01-01

    Phthalates are widely used as plasticizers in various consumer products and building materials. Some of the phthalates are known to interfere with male reproductive development in rats, and di-n-butyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were recently...

  10. Exposure to phthalic acid, phthalate diesters and phthalate monoesters from foodstuffs: UK total diet study results.

    Science.gov (United States)

    Bradley, Emma L; Burden, Richard A; Bentayeb, Karim; Driffield, Malcolm; Harmer, Nick; Mortimer, David N; Speck, Dennis R; Ticha, Jana; Castle, Laurence

    2013-01-01

    Phthalates are ubiquitous in the environment and thus exposure to these compounds can occur in various forms. Foods are one source of such exposure. There are only a limited number of studies that describe the levels of phthalates (diesters, monoesters and phthalic acid) in foods and assess the exposure from this source. In this study the levels of selected phthalate diesters, phthalate monoesters and phthalic acid in total diet study (TDS) samples are determined and the resulting exposure estimated. The methodology for the determination of phthalic acid and nine phthalate monoesters (mono-isopropyl phthalate, mono-n-butyl phthalate, mono-isobutyl phthalate, mono-benzyl phthalate, mono-cyclohexyl phthalate, mono-n-pentyl phthalate, mono-(2-ethylhexyl) phthalate, mono-n-octyl phthalate and mono-isononyl phthalate) in foods is described. In this method phthalate monoesters and phthalic acid are extracted from the foodstuffs with a mixture of acidified acetonitrile and dichloromethane. The method uses isotope-labelled phthalic acid and phthalate monoester internal standards and is appropriate for quantitative determination in the concentration range of 5-100 µg kg⁻¹. The method was validated in-house and its broad applicability demonstrated by the analysis of high-fat, high-carbohydrate and high-protein foodstuffs as well as combinations of all three major food constituents. The methodology used for 15 major phthalate diesters has been reported elsewhere. Phthalic acid was the most prevalent phthalate, being detected in 17 food groups. The highest concentration measured was di-(2-ethylhexyl) phthalate in fish (789 µg kg⁻¹). Low levels of mono-n-butyl phthalate and mono-(2-ethylhexyl) phthalate were detected in several of the TDS animal-based food groups and the highest concentrations measured corresponded with the most abundant diesters (di-n-butyl phthalate and di-(2-ethylhexyl) phthalate). The UK Committee on Toxicity of Chemicals in Food, Consumer Products

  11. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  12. Comparative Time Course Profiles of Phthalate Stereoisomers in Mice

    Science.gov (United States)

    ABSTRACT More efficient models are needed to assess potential carcinogenicity hazard of environmental chemicals. Here we evaluated time course profiles for two reference phthalates, di(2-ethylhexyl) phthalate (DEHP) and its stereoisomer di-n-octyl phthalate (DNOP), to identify...

  13. Vapour Pressure of Diethyl Phthalate

    Czech Academy of Sciences Publication Activity Database

    Roháč, V.; Růžička, K.; Růžička, V.; Zaitsau, D. H.; Kabo, G. J.; Diky, V.; Aim, Karel

    2004-01-01

    Roč. 36, č. 11 (2004), s. 929-937 ISSN 0021-9614 Institutional research plan: CEZ:AV0Z4072921 Keywords : vapour pressure * diethyl phthalate * correlation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.144, year: 2004

  14. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    Science.gov (United States)

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  15. Diimidazolium phthalate monohydrate

    Directory of Open Access Journals (Sweden)

    Chua-Hua Yu

    2012-07-01

    Full Text Available In the title compound, 2C3H5N2+·C8H4O42−·H2O, the cations, anion and water molecule are connected by N—H...O and O—H...O hydrogen bonds, forming a three-dimensional network.

  16. Hydrogen spillover in Pt-single-walled carbon nanotube composites: formation of stable C-H bonds.

    Science.gov (United States)

    Bhowmick, Ranadeep; Rajasekaran, Srivats; Friebel, Daniel; Beasley, Cara; Jiao, Liying; Ogasawara, Hirohito; Dai, Hongjie; Clemens, Bruce; Nilsson, Anders

    2011-04-13

    Using in situ electrical conductivity and ex situ X-ray photoelectron spectroscopy (XPS) measurements, we have examined how the hydrogen uptake of single-walled carbon nanotubes (SWNTs) is influenced by the addition of Pt nanoparticles. The conductivity of platinum-sputtered single-walled carbon nanotubes (Pt-SWNTs) during molecular hydrogen exposure decreased more rapidly than that of the corresponding pure SWNTs, which supports a hydrogenation mechanism facilitated by "spillover" of dissociated hydrogen from the Pt nanoparticles. C 1s XPS spectra indicate that the Pt-SWNTs store hydrogen by means of chemisorption, that is, covalent C-H bond formation: molecular hydrogen charging at elevated pressure (8.27 bar) and room temperature yielded Pt-SWNTs with up to 16 ± 1.5 at. % sp(3)-hybridized carbon atoms, which corresponds to a hydrogen-storage capacity of 1.2 wt % (excluding the weight of Pt nanoparticles). Pt-SWNTs prepared by the Langmuir-Blodgett (LB) technique exhibited the highest Pt/SWNT ratio and also the best hydrogen uptake. © 2011 American Chemical Society

  17. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  18. Transdermal uptake of diethyl phthalate and di(n-butyl) phthalate directly from air: Experimental verification

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Bekö, Gabriel; Koch, Holger M.

    2015-01-01

    of phthalate esters. Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans. Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air...

  19. 76 FR 38116 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate Substitutes

    Science.gov (United States)

    2011-06-29

    ..., and other potentially susceptible individuals; and Consider possible similar health effects of... Commission appointed this CHAP to study the effects on children's health of all phthalates and phthalate... the Commission to convene a CHAP ``to study the effects on children's health of all phthalates and...

  20. Population Exposure to Phthalate-Containing Drugs

    DEFF Research Database (Denmark)

    Broe, Anne; Ennis, Zandra Nymand; Pottegård, Anton

    2017-01-01

    Phthalates are known endocrine disruptors. Not commonly recognised, phthalates are used as excipients in a number of drug formulations. We aimed to describe the sale of phthalate-containing drugs in Denmark from 2004 to 2015. National data on annual sale of medications (tablets only) were accessed...... from medstat.dk. Data from the Danish Medicines Agency on phthalate content per tablet were merged with data on total sale for each active substance and drug formulation. We used the 'defined daily dose' (DDD) as the unit of sale and calculated the total amount of phthalate (mg) dispensed per 1......,000 inhabitants. Specific tablet content was compared with the maximum daily exposure limits defined by regulatory agencies for diethylphthalate (DEP) and dibutylphthalate (DBP) of 4.0 and 0.01 mg/kg/day, respectively. Use of phthalate-containing drugs in Denmark was common. We found 154 drug products containing...

  1. Polarization bremsstrahlung of a hydrogen-like ion in a single crystal

    International Nuclear Information System (INIS)

    Astapenko, V. A.

    2009-01-01

    Polarization bremsstrahlung (PB) that arises when a fast hydrogen-like ion is scattered in a single crystal is investigated theoretically. Four types of the process are analyzed that are caused by virtual excitation of electrons of the target and of the incident particle (IP), as well as by a coherent and incoherent interaction between the IP and the single crystal. The spectral, angular, and velocity (of the IP) characteristics of PB are calculated with regard to the spectral function of a photodetector. Optimal observation conditions and regions in which different types of PB are dominant are determined, and the dependence of these regions on the charge of the IP nucleus and of the target atoms is revealed

  2. Studies on various properties of pure and Li-doped Barium Hydrogen Phosphate (BHP) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Nallamuthu, D. [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628216, Tamil Nadu (India); Selvarajan, P., E-mail: pselvarajanphy@yahoo.co.i [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628216, Tamil Nadu (India); Freeda, T.H. [Physics Research Centre, S.T. Hindu College, Nagercoil 629002 (India)

    2010-12-15

    Single crystals of pure and Li-doped barium hydrogen phosphate (BHP) were grown by solution method with gel technique. Various properties of the harvested crystals were studied by carrying out single crystal and powder XRD, FTIR, TG/DTA, microhardness and dielectric studies. Atomic absorption study was carried out for Li-doped BHP crystal to check the presence of Li dopants. Unit cell dimensions and diffracting planes of the grown crystals have been identified from XRD studies. Functional groups of the title compounds have been identified from FTIR studies. Density of the grown crystals was calculated using the XRD data. Thermal stability of the samples was checked by TG/DTA studies. Mechanical and dielectric characterizations of the harvested pure and Li-doped BHP crystals reveal the mechanical strength and ferroelectric transition. The observed results are reported and discussed.

  3. The effects of phthalates on the ovary

    Directory of Open Access Journals (Sweden)

    Patrick eHannon

    2015-02-01

    Full Text Available Phthalates are commonly used as plasticizers in the manufacturing of flexible polyvinyl chloride products. Large production volumes of phthalates and their widespread use in common consumer, medical, building, and personal care products lead to ubiquitous human exposure via oral ingestion, inhalation, and dermal contact. Recently, several phthalates have been classified as reproductive toxicants and endocrine disrupting chemicals based on their ability to interfere with normal reproductive function and hormone signaling. Therefore, exposure to phthalates represents a public health concern. Currently, the effects of phthalates on male reproduction are better understood than the effects on female reproduction. This is of concern because women are often exposed to higher levels of phthalates than men through their extensive use of personal care and cosmetic products. In the female, a primary regulator of reproductive and endocrine function is the ovary. Specifically, the ovary is responsible for folliculogenesis, the proper maturation of gametes for fertilization, and steroidogenesis, and the synthesis of necessary sex steroid hormones. Any defect in the regulation of these processes can cause complications for reproductive and non-reproductive health. For instance, phthalate-induced defects in folliculogenesis and steroidogenesis can cause infertility, premature ovarian failure, and non-reproductive disorders. Presently, there is a paucity of knowledge on the effects of phthalates on normal ovarian function; however, recent work has established the ovary as a target of phthalate toxicity. This review summarizes what is currently known about the effects of phthalates on the ovary and the mechanisms by which phthalates exert ovarian toxicity, with a particular focus on the effects on folliculogenesis and steroidogenesis. Further, this review outlines future directions including the necessity of examining the effects of phthalates at doses that mimic

  4. 27 CFR 21.106 - Diethyl phthalate.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Diethyl phthalate. 21.106....106 Diethyl phthalate. (a) Refractive index at 25 °C. 1.497 to 1.502. (b) Color. Colorless. (c) Odor... °/25 °C. 1.115 to 1.118. (f) Ester content (as diethyl phthalate). Not less than 99 percent by weight...

  5. Luminescent micro- and nanofibers based on novel europium phthalate complex

    Energy Technology Data Exchange (ETDEWEB)

    Enculescu, M., E-mail: mdatcu@infim.ro [National Institute of Materials Physics, Multifunctional Materials and Structures, PO Box MG-7, 77125 Magurele-Bucharest (Romania); Preda, N.; Matei, E.; Enculescu, I. [National Institute of Materials Physics, Multifunctional Materials and Structures, PO Box MG-7, 77125 Magurele-Bucharest (Romania)

    2012-09-14

    We synthesized by wet chemical route a novel europium-potassium phthalate complex Eu{sup 3+}K{sup +}[(COO){sub 2}(C{sub 6}H{sub 4})]{sub 2}. The compound is a white powder insoluble in water. X-ray diffraction evaluation shows that we obtained a new crystalline compound with no traces of the starting materials (potassium hydrogen phthalate and europium chloride). Scanning electron microscopy reveals that the powder consists of fiber-shaped structures with sizes larger than 250 nm in diameter. Energy dispersive X-ray analysis proves that the compound has a 1:1 europium-potassium ratio. Fourier transform infrared spectroscopy confirms the presence of the phthalate in the new compound. Photoluminescence and cathodoluminescence measurements show that the fiber-shaped structures are intensely luminescent with emission bands corresponding to the {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1-4) Eu (III) ion's transitions in the region between 580 nm and 700 nm, the most intense maximum being observed around 615 nm. Up-converted luminescence with a maximum at 315 nm was recorded. -- Highlights: Black-Right-Pointing-Pointer A new europium-potassium phthalate complex was synthesized by wet chemical route. Black-Right-Pointing-Pointer Fiber-shaped crystalline structures with sizes larger than 250 nm. Black-Right-Pointing-Pointer The most probable structure of the molecule is [C{sub 6}H{sub 4}(COO{sup -}){sub 2}]{sub 2} K{sup +}Eu{sup 3+}. Black-Right-Pointing-Pointer Intense luminescence due to Eu{sup 3+} ions {sup 5}D{sub 0} {yields} {sup 7}F{sub J} transitions. Black-Right-Pointing-Pointer Up-converted luminescence with a maximum at 315 nm was recorded.

  6. Review of Phthalates Exposure and Toxicity

    Directory of Open Access Journals (Sweden)

    Samaneh Taghilou

    2015-12-01

    Full Text Available The dialkyl- or alkyl/aryl esters of 1, 2-benzenedicarboxylic acid, which are known as Phthalates, are high-production volume synthetic chemicals and considered as environmental pollutants, due to high production and uses in community, plastics industry and common consuming products. Di-(2-ethylhexyl phthalate (DEHP is the most abundant phthalate in the environment. Human exposure with DEHP could be done via different chemical compounds including food packaging, household furnishings, nutritional supplements, cleaning materials and insecticides. Besides, exposure of human with phthalates occurs through different pathways such as direct contact and using Phthalate-containing products, and indirectly through leaching into other products, or general environmental contaminations. Historically, the diet has been considered the major source of phthalate exposure in the general population, but in all sources, pathways, and their relative contributions to human exposures are not well understood. Medical devices are other source of significant exposure in human. Furthermore, cosmetics, personal care products, pharmaceuticals, nutritional supplements, herbal remedies and insecticides, may result in significant but poorly quantified human exposure with this compounds. In the present review article, we tried to discuss about metabolism of phthalates in human, toxicity, monitoring of phthalates in foods, environment, and cosmetic products and then metabolites of phthalates. Finally, evaluation of human exposure through biological control is discussed.

  7. Serum Phthalate and Triclosan Levels Have Opposing Associations With Risk Factors for Gestational Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Benjamin G. Fisher

    2018-03-01

    Full Text Available Certain phthalates and bisphenol A (BPA have been associated with insulin resistance and type 2 diabetes in non-pregnant adults, but studies of gestational diabetes mellitus (GDM have reported conflicting results for phthalates and no associations with BPA. Our aim was to investigate the relationship between maternal serum levels of phthalate metabolites and phenols at 10–17 weeks of gestation and glucose homeostasis at 28 weeks of gestation. 232 women aged ≥16 years without type 1 or 2 diabetes with singleton male pregnancies were recruited from a single UK maternity centre between 2001 and 2009 as part of a prospective observational study (Cambridge Baby Growth Study. Serum levels of 16 phthalate metabolites and 9 phenols (including BPA were measured using liquid chromatography/tandem mass spectrometry. Oral glucose tolerance tests were performed at 28 weeks. 47/232 (20.3% women had GDM. First-trimester triclosan (TCS was inversely associated with incident GDM (adjusted odds ratio per log increase in concentration 0.54, 95% confidence interval 0.34–0.86, p = 0.010. Amongst women without GDM, first-trimester mono-(2-ethylhexyl phthalate and mono(carboxyisooctyl phthalate levels were positively associated with 120-min plasma glucose (adjusted β 0.268 and 0.183, p = 0.0002 and 0.010, respectively in mid-pregnancy. No other monotonic associations were detected between phthalate or phenol levels and fasting or stimulated plasma glucose, β-cell function, insulin resistance, or 60-min disposition index. Our results support a glycaemia-raising effect of phthalates during pregnancy, consistent with findings in non-pregnant populations and suggest a possible protective effect of exposure to TCS against GDM.

  8. Improved detection limits for phthalates by selective solid-phase micro-extraction

    KAUST Repository

    Zia, Asif I.

    2016-03-30

    Presented research reports on an improved method and enhanced limits of detection for phthalates; a hazardous additive used in the production of plastics by solid-phase micro-extraction (SPME) polymer in comparison to molecularly imprinted solid-phase extraction (MISPE) polymer. The polymers were functionalized on an interdigital capacitive sensor for selective binding of phthalate molecules from a complex mixture of chemicals. Both polymers owned predetermined selectivity by formation of valuable molecular recognition sites for Bis (2-ethylhexyl) phthalate (DEHP). Polymers were immobilized on planar electrochemical sensor fabricated on a single crystal silicon substrate with 500 nm sputtered gold electrodes fabricated using MEMS fabrication techniques. Impedance spectra were obtained using electrochemical impedance spectroscopy (EIS) to determine sample conductance for evaluation of phthalate concentration in the spiked sample solutions with various phthalate concentrations. Experimental results revealed that the ability of SPME polymer to adsorb target molecules on the sensing surface is better than that of MISPE polymer for phthalates in the sensing system. Testing the extracted samples using high performance liquid chromatography with photodiode array detectors validated the results.

  9. Optimization Study of Hydrogen Gas Adsorption on Zig-zag Single-walled Carbon Nanotubes: The Artificial Neural Network Analysis

    Science.gov (United States)

    Nasruddin; Lestari, M.; Supriyadi; Sholahudin

    2018-03-01

    The use of hydrogen gas in fuel cell technology has a huge opportunity to be applied in upcoming vehicle technology. One of the most important problems in fuel cell technology is the hydrogen storage. The adsorption of hydrogen in carbon-based materials attracts a lot of attention because of its reliability. This study investigated the adsorption of hydrogen gas in Single-walled Carbon Nano Tubes (SWCNT) with chilarity of (0, 12), (0, 15), and (0, 18) to find the optimum chilarity. Artificial Neural Networks (ANN) can be used to predict the hydrogen storage capacity at different pressure and temperature conditions appropriately, using simulated series of data. The Artificial Neural Network is modeled as a predictor of the hydrogen adsorption capacity which provides solutions to some deficiencies in molecular dynamics (MD) simulations. In a previous study, ANN configurations have been developed for 77k, 233k, and 298k temperatures in hydrogen gas storage. To prepare this prediction, ANN is modeled to find out the configurations that exist in the set of training and validation of specified data selection, the distance between data, and the number of neurons that produce the smallest error. This configuration is needed to make an accurate artificial neural network. The configuration of neural network was then applied to this research. The neural network analysis results show that the best configuration of artificial neural network in hydrogen storage is at 233K temperature i.e. on SWCNT with chilarity of (0.12).

  10. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mahesh Iyer; Himanshu Gupta; Danny Wong; Liang-Shih Fan

    2005-09-30

    Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project aims at using the OSU patented high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. Gas composition analyses show the formation of 100% pure hydrogen. Novel calcination techniques could lead to smaller reactor footprint and single-stage reactors that can achieve maximum theoretical H{sub 2} production for multicyclic applications. Sub-atmospheric calcination studies reveal the effect of vacuum level, diluent gas flow rate, thermal properties of the diluent gas and the sorbent loading on the calcination kinetics which play an important role on the sorbent morphology. Steam, which can be easily separated from CO{sub 2}, is envisioned to be a potential diluent gas due to its enhanced thermal properties. Steam calcination studies at 700-850 C reveal improved sorbent morphology over regular nitrogen calcination. A mixture of 80% steam and 20% CO{sub 2} at ambient pressure was used to calcine the spent sorbent at 820 C thus lowering the calcination temperature. Regeneration of calcium sulfide to calcium carbonate was achieved by carbonating the calcium sulfide slurry by bubbling CO{sub 2} gas at room temperature.

  11. Sources of Phthalates and Nonylphenoles in Municipal Waste Water

    DEFF Research Database (Denmark)

    Vikelsøe, J.; Thomsen, M.; Johansen, E.

    The overall aim of the present study is to identify and evaluate the importance of sources of nonylphenoles and phthalates in waste water in a local environment. The investigations were carried out in a Danish local community, Roskilde city and surroundings. Nonylphenoles and phthalates were...... analysed in the waste water from different institutions and industries thought to be potential sources. These were: car wash centers, a hospital, a kindergarten, an adhesive industry and a industrial laundry. Furthermore, analysis of the deposition in the area were carried out. This made it possible...... to estimate the contribution from all of these sources to the waste water as well as the role of long-range air transport. Two local rivers were analysed for comparison. Finally, waste water inlet from the local water treatment plant, where the sources converge at a single point, were analysed. A mass balance...

  12. Comparison of cell encapsulation technologies for single pressure vessel nickel-hydrogen battery

    Energy Technology Data Exchange (ETDEWEB)

    Rao, G. [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Vaidyanathan, H. [COMSAT Labs., Clarksburg, MD (United States)

    1996-12-31

    Two single pressure vessel (SPV) batteries containing 22 series-connected nickel-hydrogen (Ni-H{sub 2}) cells of 19-Ah capacity were designed and procured from Eagle-Picher Industries. The two batteries were similar in mechanical design, dimensions, and composition of the active core. However, they differed in cell encapsulation, location and structure of the gas diffusion membrane, and cell activation. Both batteries have been subjected to detailed flight qualification testing at COMSAT Laboratories. The batteries met the requirements in capacity, capacity retention, discharge voltage, impedance, thermal behavior in vacuum, and response to vibration. The batteries are currently being cycle tested in a low earth orbit (LEO) regime using V-T charge control at a depth of discharge of 40% and at 20 C. The battery design, and its characterization, environmental, and LEO cycle test data are presented.

  13. Thermal, mechanical, optical and dielectric properties of piperazinium hydrogen phosphite monohydrate NLO single crystal

    Science.gov (United States)

    Rajkumar, R.; Praveen Kumar, P.

    2018-05-01

    Optical transparent crystal of piperazinium hydrogen phosphite monohydrate (PHPM) was grown by slow evaporation method. The grown crystal was characterized by single crystal X-ray diffraction analysis and the crystal belongs to monoclinic system. The functional groups present in PHPM crystal were confirmed by FTIR analysis. UV-Visible spectrum shows that the PHPM crystal is transparent in the visible region. The mechanical behavior of PHPM crystal was characterized by Vickers hardness test. Thermal stability of PHPM crystal was analyzed by thermogravimetric analysis. Dielectric studies were also carried out for the grown crystal. The third-order nonlinear parameters such as nonlinear refractive index and nonlinear absorption coefficient have been calculated using Z scan technique.

  14. Production and ejection of solid hydrogen-isotope pellet (single pellet)

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Hasegawa, Koichi; Miura, Yukitoshi; Ishibori, Ikuo

    1986-03-01

    The pneumatic gun type pellet injector (single pellet) has been constructed, which is basic type used at ORNL. The pellet in the carrier is 1.65 mm in diameter and 1.65 mm in length, and another is 1 mmD x 1 mmL. Hydrogen pellet velocity of about 900 m/s was observed at propellant gas (He) pressure of 14 kg/cm 2 . In the injection experiment into a plasma, typical velocity is 714 ∼ 833 m/s. These values are 80 ∼ 95 % of velocity calculated from the ideal gun model. The ejected pellet size is 71 ∼ 90 % of the hole size in the carrier disk (1.65 mmD x 1.65 mmL) and 46 ∼ 56 % (1 mmD x 1 mmL). The spread in the pellet trajectories is about 26 mm in diameter at a plasma center. (author)

  15. First trimester phthalate exposure and anogenital distance in newborns

    Science.gov (United States)

    Swan, S.H.; Sathyanarayana, S.; Barrett, E.S.; Janssen, S.; Liu, F.; Nguyen, R.H.N.; Redmon, J.B.; Liu, Fan; Scher, Erica; Stasenko, Marina; Ayash, Erin; Schirmer, Melissa; Farrell, Jason; Thiet, Mari-Paule; Baskin, Laurence; Gray Chelsea Georgesen, Heather L.; Rody, Brooke J.; Terrell, Carrie A.; Kaur, Kapilmeet; Brantley, Erin; Fiore, Heather; Kochman, Lynda; Parlett, Lauren; Marino, Jessica; Hulbert, William; Mevorach, Robert; Pressman, Eva; Ivicek, Kristy; Salveson, Bobbie; Alcedo, Garry

    2015-01-01

    collection, maternal age and study center. MAIN RESULTS AND THE ROLE OF CHANCE Three metabolites of DEHP were significantly and inversely associated with both measures of boys' AGD. Associations (β, 95% confidence interval (CI)) between AGDAS and (log10) SpG-adjusted phthalate concentrations were: −1.12 (−2.16, −0.07) for mono-2-ethylhexyl phthalate (MEHP), −1.43, (−2.49, −0.38) for mono-2-ethyl-5-oxohexyl phthalate (MEOHP), and −1.28 (−2.29, −0.27) for mono-2-ethyl-5-hydroxyhexyl (MEHHP). Associations were of similar magnitude for AGDAP. Associations were weaker and not statistically significant for PW. No other phthalate metabolites were associated with any genital measurement in boys. No phthalate metabolites were associated with either AGD measure in girls. LIMITATIONS, REASONS FOR CAUTION Exposure assessment was based on a single first trimester urine sample, which may have introduced exposure misclassification. In addition, significant between-center differences suggest that this measurement is difficult to standardize. WIDER IMPLICATIONS OF THE FINDINGS Our findings are consistent with multiple rodent studies and most human studies which were far smaller. The data we report here suggest that even at current low levels, environmental exposure to DEHP can adversely affect male genital development resulting in reproductive tract changes that may impact reproductive health later in life. These findings have important implications for public policy since most pregnant women are exposed to this ubiquitous chemical. STUDY FUNDING/COMPETING INTEREST(S) Funding for TIDES was provided by the following grants from the National Institute of Environmental Health Sciences: R01ES016863-04 and R01 ES016863-02S4. The authors report no conflict of interest. PMID:25697839

  16. Reproductive and Developmental Toxicity of Phthalates

    NARCIS (Netherlands)

    Lyche, J.L.; Gutleb, A.C.; Bergman, A.; Eriksen, G.S.; Murk, A.J.; Ropstad, E.; Saunders, M.; Skaare, J.U.

    2009-01-01

    The purposes of this review are to (1) evaluate human and experimental evidence for adverse effects on reproduction and development in humans, produced by exposure to phthalates, and (2) identify knowledge gaps as for future studies. The widespread use of phthalates in consumer products leads to

  17. Are Medicinal Plants Polluted with Phthalates?

    Directory of Open Access Journals (Sweden)

    Soodabeh Saeidnia

    2013-05-01

    Full Text Available Phthalic acid esters (PAEs have been employed in polymer materials as a plasticizer to form them more flexible, adhesive, and soluble. These compounds are mainly used in paints, varnishes, personal cares, cosmetics, paper coatings, and adhesives even in bottled waters, shampoo, body deodorant, hairspray, and gels. Phthalates are able to possess remarkable toxic variations depending on their structures. So far, Di-(2-EthylHexyl Phthalate DEHP and Di-n- Butyl Phthalate DBP have been found to cause reproductive and developmental toxicities. The U.S. Environmental Protection Agency (EPA classified DEHP as probable human carcinogen. To the best of our knowledge, phthalates showed diverse toxicity profiles according to their structures in the liver, kidneys, thyroid, and testes, which are involved in general toxicity. Furthermore, they are introduced as hormonally-active agents, because they can interfere with the endocrine system in human. Incidence of developmental abnormalities (like skeletal malformations and cleft palate, and undescended testes, lowering testes weight and anogenital distance seems increasing via high exposure to phthalate metabolites. Although, increasing the capacity for phthalate free plasticizer productions is the first step to restrict the distribution of these toxic manmade compounds, finding the new ways for phthalate absorption from the soil in agricultural fields may have benefits. Also, evaluation and examination of diverse sources of medicinal and food plants to determine the level of phthalate accumulation in their organs are extremely recommended to avoid creating toxicity particularly in reproductive systems.

  18. Effects of Prenatal Exposure to Phthalates

    Science.gov (United States)

    Johnson, Laurie A.

    2012-01-01

    The purpose of this review of literature is to examine the association of phthalate exposure with development. Phthalates are chemical compounds used in poly-vinyl chloride, PVC; vinyl flooring, cosmetics, shampoo, air fresheners, soft plastic items, intravenous tubing, food packaging and wraps, textiles, paints, cleaning products and detergents.…

  19. Performance of Pd on activated carbon as hydrogen electrode with respect to hydrogen yield in a single cell proton exchange membrane (PEM) water electrolyser

    Energy Technology Data Exchange (ETDEWEB)

    Naga Mahesh, K.; Sarada Prasad, J.; Venkateswer Rao, M.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad 500085 (A.P.) (India); Yerramilli, Anjaneyulu [TLGVRC, JSU Box 18739, Jackson State University, Jackson, MS 32917 - 0939 (United States); Raghunathan Rao, P. [Fuel cell section, Heavy Water Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

    2009-08-15

    Palladium (Pd) on activated carbon is used as electrocatalyst coated on Nafion 115 membrane as Hydrogen electrode and RuO{sub 2} is coated on other side of membrane used as oxygen electrode. 5 wt% and 10 wt% Pd on activated carbon is prepared as membrane electrode assembly (MEA) and investigated the performance of the same using inhouse prepared 10 cm{sup 2} single cell. The performance of the single cell assembly and the hydrogen yield are reported during electrolysis operation at temperatures 27 C, 45 C and 65 C at 0.1, 0.2, 0.3, 0.4, 0.5 A/cm{sup 2} current densities with respect to voltages. (author)

  20. Pt Single Atoms Embedded in the Surface of Ni Nanocrystals as Highly Active Catalysts for Selective Hydrogenation of Nitro Compounds.

    Science.gov (United States)

    Peng, Yuhan; Geng, Zhigang; Zhao, Songtao; Wang, Liangbing; Li, Hongliang; Wang, Xu; Zheng, Xusheng; Zhu, Junfa; Li, Zhenyu; Si, Rui; Zeng, Jie

    2018-06-13

    Single-atom catalysts exhibit high selectivity in hydrogenation due to their isolated active sites, which ensure uniform adsorption configurations of substrate molecules. Compared with the achievement in catalytic selectivity, there is still a long way to go in exploiting the catalytic activity of single-atom catalysts. Herein, we developed highly active and selective catalysts in selective hydrogenation by embedding Pt single atoms in the surface of Ni nanocrystals (denoted as Pt 1 /Ni nanocrystals). During the hydrogenation of 3-nitrostyrene, the TOF numbers based on surface Pt atoms of Pt 1 /Ni nanocrystals reached ∼1800 h -1 under 3 atm of H 2 at 40 °C, much higher than that of Pt single atoms supported on active carbon, TiO 2 , SiO 2 , and ZSM-5. Mechanistic studies reveal that the remarkable activity of Pt 1 /Ni nanocrystals derived from sufficient hydrogen supply because of spontaneous dissociation of H 2 on both Pt and Ni atoms as well as facile diffusion of H atoms on Pt 1 /Ni nanocrystals. Moreover, the ensemble composed of the Pt single atom and nearby Ni atoms in Pt 1 /Ni nanocrystals leads to the adsorption configuration of 3-nitrostyrene favorable for the activation of nitro groups, accounting for the high selectivity for 3-vinylaniline.

  1. Variability of Urinary Phthalate Metabolite and Bisphenol A Concentrations before and during Pregnancy

    Science.gov (United States)

    Braun, Joe M.; Smith, Kristen W.; Williams, Paige L.; Calafat, Antonia M.; Berry, Katharine; Ehrlich, Shelley

    2012-01-01

    Background: Gestational phthalate and bisphenol A (BPA) exposure may increase the risk of adverse maternal/child health outcomes, but there are few data on the variability of urinary biomarkers before and during pregnancy. Objective: We characterized the variability of urinary phthalate metabolite and BPA concentrations before and during pregnancy and the ability of a single spot urine sample to classify average gestational exposure. Methods: We collected 1,001 urine samples before and during pregnancy from 137 women who were partners in couples attending a Boston fertility clinic and who had a live birth. Women provided spot urine samples before (n ≥ 2) and during (n ≥ 2) pregnancy. We measured urinary concentrations of monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-iso-butyl phthalate, monobenzyl phthalate (MBzP), four metabolites of di-(2-ethylhexyl) phthalate (DEHP), and BPA. After adjusting for specific gravity, we characterized biomarker variability using intraclass correlation coefficients (ICCs) and conducted several surrogate category analyses to determine whether a single spot urine sample could adequately classify average gestational exposure. Results: Absolute concentrations of phthalate metabolites and BPA were similar before and during pregnancy. Variability was higher during pregnancy than before pregnancy for BPA and MBzP, but similar during and before pregnancy for MBP, MEP, and ΣDEHP. During pregnancy, MEP (ICC = 0.50) and MBP (ICC = 0.45) were less variable than BPA (ICC = 0.12), MBzP (ICC = 0.25), and ΣDEHP metabolites (ICC = 0.08). Surrogate analyses suggested that a single spot urine sample may reasonably classify MEP and MBP concentrations during pregnancy, but more than one sample may be necessary for MBzP, DEHP, and BPA. Conclusions: Urinary phthalate metabolites and BPA concentrations were variable before and during pregnancy, but the magnitude of variability was biomarker specific. A single spot urine sample

  2. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Hun

    1996-02-15

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10{sup -7} m {center_dot} rad and 7.87 x 10{sup -9}A {center_dot} V{sup -3/2}, respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics.

  3. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    International Nuclear Information System (INIS)

    Kim, Su Hun

    1996-02-01

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10 -7 m · rad and 7.87 x 10 -9 A · V -3/2 , respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics

  4. Revisiting the inelastic electron tunneling spectroscopy of single hydrogen atom adsorbed on the Cu(100) surface

    International Nuclear Information System (INIS)

    Jiang, Zhuoling; Wang, Hao; Sanvito, Stefano; Hou, Shimin

    2015-01-01

    Inelastic electron tunneling spectroscopy (IETS) of a single hydrogen atom on the Cu(100) surface in a scanning tunneling microscopy (STM) configuration has been investigated by employing the non-equilibrium Green’s function formalism combined with density functional theory. The electron-vibration interaction is treated at the level of lowest order expansion. Our calculations show that the single peak observed in the previous STM-IETS experiments is dominated by the perpendicular mode of the adsorbed H atom, while the parallel one only makes a negligible contribution even when the STM tip is laterally displaced from the top position of the H atom. This propensity of the IETS is deeply rooted in the symmetry of the vibrational modes and the characteristics of the conduction channel of the Cu-H-Cu tunneling junction, which is mainly composed of the 4s and 4p z atomic orbitals of the Cu apex atom and the 1s orbital of the adsorbed H atom. These findings are helpful for deepening our understanding of the propensity rules for IETS and promoting IETS as a more popular spectroscopic tool for molecular devices

  5. Characterization of Urinary Phthalate Metabolites Among Custodians

    Science.gov (United States)

    Cavallari, Jennifer M.; Simcox, Nancy J.; Wakai, Sara; Lu, Chensheng; Garza, Jennifer L.; Cherniack, Martin

    2015-01-01

    Phthalates, a ubiquitous class of chemicals found in consumer, personal care, and cleaning products, have been linked to adverse health effects. Our goal was to characterize urinary phthalate metabolite concentrations and to identify work and nonwork sources among custodians using traditional cleaning chemicals and ‘green’ or environmentally preferable products (EPP). Sixty-eight custodians provided four urine samples on a workday (first void, before shift, end of shift, and before bedtime) and trained observers recorded cleaning tasks and types of products used (traditional, EPP, or disinfectant) hourly over the work shifts. Questionnaires were used to assess personal care product use. Four different phthalate metabolites [monoethyl phthalate (MEP), monomethyl phthalate (MMP), mono (2-ethylhexyl) phthalate (MEHP), and monobenzyl phthalate (MBzP)] were quantified using liquid chromatography mass spectrometry. Geometric means (GM) and 95% confidence intervals (95% CI) were calculated for creatinine-adjusted urinary phthalate concentrations. Mixed effects univariate and multivariate modeling, using a random intercept for each individual, was performed to identify predictors of phthalate metabolites including demographics, workplace factors, and personal care product use. Creatinine-adjusted urinary concentrations [GM (95% CI)] of MEP, MMP, MEHP, and MBzP were 107 (91.0–126), 2.69 (2.18–3.30), 6.93 (6.00–7.99), 8.79 (7.84–9.86) µg g−1, respectively. An increasing trend in phthalate concentrations from before to after shift was not observed. Creatinine-adjusted urinary MEP was significantly associated with frequency of traditional cleaning chemical intensity in the multivariate model after adjusting for potential confounding by demographics, workplace factors, and personal care product use. While numerous demographics, workplace factors, and personal care products were statistically significant univariate predictors of MMP, MEHP, and MBzP, few

  6. Growth and detachment of single hydrogen bubbles in a magnetohydrodynamic shear flow

    Science.gov (United States)

    Baczyzmalski, Dominik; Karnbach, Franziska; Mutschke, Gerd; Yang, Xuegeng; Eckert, Kerstin; Uhlemann, Margitta; Cierpka, Christian

    2017-09-01

    This study investigates the effect of a magnetohydrodynamic (MHD) shear flow on the growth and detachment of single sub-millimeter-sized hydrogen gas bubbles. These bubbles were electrolytically generated at a horizontal Pt microelectrode (100 μ m in diameter) in an acidic environment (1 M H2SO4 ). The inherent electric field was superimposed by a homogeneous electrode-parallel magnetic field of up to 700 mT to generate Lorentz forces in the electrolyte, which drive the MHD flow. The growth and motion of the hydrogen bubble was analyzed by microscopic high-speed imaging and measurements of the electric current, while particle tracking velocimetry (μ PTV ) and particle image velocimetry (μ PIV ) were applied to measure the surrounding electrolyte flow. In addition, numerical flow simulations were performed based on the experimental conditions. The results show a significant reduction of the bubble growth time and detachment diameter with increasing magnetic induction, which is known to improve the efficiency of water electrolysis. In order to gain further insight into the bubble detachment mechanism, an analysis of the forces acting on the bubble was performed. The strong MHD-induced drag force causes the bubble to slowly slide away from the center of the microelectrode before its detachment. This motion increases the active electrode area and enhances the bubble growth rate. The results further indicate that at large current densities the coalescence of tiny bubbles formed at the foot of the main bubble might play an important role for the bubble detachment. Moreover, the occurrence of Marangoni stresses at the gas-liquid interface is discussed.

  7. Single-Photon Ionization Soft-X-Ray Laser Mass Spectrometry of Potential Hydrogen Storage Materials

    Science.gov (United States)

    Dong, F.; Bernstein, E. R.; Rocca, J. J.

    A desk-top size capillary discharge 46.9 nm lasear is applied in the gas phase study of nanoclusters. The high photon energy allows for single-photon ionization mass spectrometry with reduced cluster fragmentation. In the present studies, neutral Al m C n and Al m C n H x cluster are investigation for the first time. Single photon ionization through 46.9 nm, 118 nm, 193 nm lasers is used to detect neutral cluster distributions through time of flight mass spectrometry. Al m C n clusters are generated through laser ablation of a mixture of Al and C powders pressed into a disk. An oscillation of the vertical ionization energies (VIEs) of Al m C n clusters is observed in the experiments. The VIEs of Al m C n clusters changes as a function of the numbers of Al and C atoms in the clusters. Al m C n H x clusters are generated through an Al ablation plasma-hydrocarbon reaction, an Al-C ablation plasma reacting with H2 gas, or through cold Al m C n clusters reacting with H2 gas in a fast flow reactor. DFT and ab inito calculations are carried out to explore the structures, IEs, and electronic structures of Al m C n H x clusters. C=C bonds are favored for the lowest energy structures for Al m C n clusters. Be m C n H x are generated through a beryllium ablation plasma-hydrocarbon reaction and detected by single photon ionization of 193 nm laser. Both Al m C n H x and Be m C n H x are considered as potential hydrogen storage materials.

  8. Study on the interaction of phthalate esters to human serum albumin by steady-state and time-resolved fluorescence and circular dichroism spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xiaoyun [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Wang, Zhaowei [College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Zhou, Ximin; Wang, Xiaoru [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2011-09-15

    Highlights: {center_dot} Molecular docking revealed PAEs to be located in the hydrophobic pocket of HSA. {center_dot} HSA-DMP had one class of binding sites while HSA-BBP and HSA-DEHP had two types. {center_dot} Hydrophobic and hydrogen interactions dominated in the association of HSA-PAEs. {center_dot} The lifetime of Trp residue of HSA decreased after the addition of PAEs. {center_dot} The presences of PAEs could alter the second structure of HSA. - Abstract: Phthalate esters (PAEs) are globally pervasive contaminants that are considered to be endocrine disruptor chemicals and toxic environmental priority pollutants. In this paper, the interactions between PAEs and human serum albumin (HSA) were examined by molecular modelling, steady state and time-resolved fluorescence, ultraviolet-visible spectroscopy (UV-vis) and circular dichroism spectroscopy (CD). The association constants between PAEs and HSA were determined using the Stern-Volmer and Scatchard equations. The binding of dimethyl phthalate (DMP) to HSA has a single class of binding site and its binding constants (K) are 4.08 x 10{sup 3}, 3.97 x 10{sup 3}, 3.45 x 10{sup 3}, and 3.20 x 10{sup 3} L mol{sup -1} at 289, 296, 303, and 310 K, respectively. The Stern-Volmer and Scatchard plots both had two regression curves for HSA-butylbenzyl phthalate (BBP) and HSA-di-2-ethylhexyl phthalate (DEHP), which indicated that these bindings were via two types of binding sites: the numbers of binding site for the first type were lower than for the second type. The binding constants of the first type binding site were higher than those of the second type binding site at corresponding temperatures, the results suggesting that the first type of binding site had high affinity and the second binding site involved other sites with lower binding affinity and selectivity. The thermodynamic parameters of the binding reactions ({Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o}) were measured, and they indicated the presences

  9. Phthalate pollution in an Amazonian rainforest.

    Science.gov (United States)

    Lenoir, Alain; Boulay, Raphaël; Dejean, Alain; Touchard, Axel; Cuvillier-Hot, Virginie

    2016-08-01

    Phthalates are ubiquitous contaminants and endocrine-disrupting chemicals that can become trapped in the cuticles of insects, including ants which were recognized as good bioindicators for such pollution. Because phthalates have been noted in developed countries and because they also have been found in the Arctic, a region isolated from direct anthropogenic influence, we hypothesized that they are widespread. So, we looked for their presence on the cuticle of ants gathered from isolated areas of the Amazonian rainforest and along an anthropogenic gradient of pollution (rainforest vs. road sides vs. cities in French Guiana). Phthalate pollution (mainly di(2-ethylhexyl) phthalate (DEHP)) was higher on ants gathered in cities and along road sides than on those collected in the pristine rainforest, indicating that it follows a human-mediated gradient of disturbance related to the use of plastics and many other products that contain phthalates in urban zones. Their presence varied with the ant species; the cuticle of Solenopsis saevissima traps higher amount of phthalates than that of compared species. However, the presence of phthalates in isolated areas of pristine rainforests suggests that they are associated both with atmospheric particles and in gaseous form and are transported over long distances by wind, resulting in a worldwide diffusion. These findings suggest that there is no such thing as a "pristine" zone.

  10. MEMS based impedimetric sensing of phthalates

    KAUST Repository

    Zia, Asif I.

    2013-05-01

    Phthalate esters are known ubiquitous teratogenic and carcinogenic environmental and food pollutants. Their detection and quantification is strictly laboratory based, time consuming, expensive and professionally handled procedure. Presented research work describes a real time non-invasive detection technique for phthalates detection in ethanol, water and drinks. The new type of inter-digital sensor design incorporating multiple sensing gold electrodes were fabricated on silicon substrate based on thin film micro-electromechanical system (MEMS) using semiconductor device fabrication technology. A passivation layer of Silicon Nitride (Si3N4) was used to functionalize the sensor. Various concentrations (0.1 to 20ppm) of DINP (di-isononyl phthalates) in ethanol and di (2-ethylhexyl) phthalate (DEHP) in deionized MilliQ water were subjected to the testing system by dip testing method. Electrochemical impedance spectroscopy (EIS) technique was used to obtain impedance spectra in order to determine sample conductance for evaluation of its dielectric properties. The impedance spectra so obtained showed that the sensor was able to detect the presence of phthalates in the samples distinctively. Electrochemical Spectrum Analyser was used to model the experimentally obtained impedance spectra by curve fitting technique to figure out Constant Phase Element (CPE) equivalent circuit. Locally available energy drink and juice was added with phthalates in concentrations of 2, 6 and 10ppm to observe the performance of the sensor in such products. Experimental results showed that the new sensor was able to detect different concentrations of phthalates in energy drinks. © 2013 IEEE.

  11. Correlation of phthalate exposures with semen quality

    International Nuclear Information System (INIS)

    Pant, Niraj; Shukla, Manju; Kumar Patel, Devendra; Shukla, Yogeshwar; Mathur, Neeraj; Kumar Gupta, Yogendra; Saxena, Daya Krishna

    2008-01-01

    Phthalates are widely used man-made chemical released in the environment and human exposure is mainly through diet. As the phthalate plasticizers are not covalently bound to PVC, they can leach, migrate or evaporate into the environment and as a result have become ubiquitously contaminants. The present study investigates the correlation, if any, between the phthalate esters (DEP, DEHP, DBP, DMP, DOP) and sperm mitochondrial status, ROS, LPO, SCSA, and sperm quality. The study was conducted in the urban/rural population of Lucknow visiting Obstetrics and Gynecology Department, CSMMU, Lucknow. Semen analysis was performed according to the WHO guidelines while phthalate analysis by HPLC and LPO by spectrophotometer and the sperm mitochondrial status, ROS, SCSA using flow cytometry. The questionnaire data showed no significant difference in the demographic characteristics among the groups. In general, urban population was found to have statistically significant higher levels of phthalate esters than the rural. Further, infertile men showed statistically significant (p < 0.05) higher levels of pollutants in the semen than fertile men. A negative correlation between semen phthalate level viz DEHP and sperm quality and positive association with depolarized mitochondria, elevation in ROS production and LPO, DNA fragmentation was established. The findings are suggestive that phthalates might be one among the contributing factors associated with the deterioration in semen quality and these adverse effects might be ROS, LPO and mitochondrial dysfunction mediated

  12. The association between phthalate exposure and asthma

    Directory of Open Access Journals (Sweden)

    Ming-Ju Tsai

    2012-07-01

    Full Text Available Asthma is a chronic inflammatory disorder of the airway, characterized by airway hyperresponsiveness. It is a disabling disease with an increasing prevalence, resulting in heavy social and economic burdens worldwide. Humans are extensively exposed to phthalates, and many epidemiological studies have shown a relationship between phthalate exposure and asthma in recent decades. Earlier experimental studies focused on inflammatory cells, demonstrating the adjuvant effects, immunomodulatory effects, or immunosuppressive effects related to phthalate exposure. Recent studies have shown that phthalates may have a direct effect on airway epithelial cells and contribute to airway remodeling, which is the cardinal pathologic characteristic of chronic asthma, with a high correlation with disease severity. Through these efforts, phthalates have been recognized as important environmental factors in the pathogenesis of asthma, but further studies are still required to elucidate the detailed mechanism. This review discusses the current status of human exposure to phthalates in Taiwan and summarizes the epidemiological and experimental evidence related to the roles of phthalate exposure in the development of asthma and associated diseases.

  13. [Relationship between phthalates and testicular dysgenesis syndrome].

    Science.gov (United States)

    Chen, Guo-Rong; Dong, Lei; Ge, Ren-Shan; Hardy, Matthew P

    2007-03-01

    Recent epidemiological evidence demonstrates that boys born to women exposed to phthalates during pregnancy have an increased incidence of cryptorchidism, hypospadias, testicular cancer and spermatogenic dysfunction, which are collectively referred to as testicular dysgenesis syndrome (TDS). TDS may be attributed to the dysfunction of Leydig cells and Sertoli cells during their differentiation after exposure to phthalates in utero. Fox example, Leydig cell functions are significantly affected by phthalates, leading to the decrease of two Leydig cell products--insulin-like growth factor 3 (INSL3) and testosterone, which are critical factors for testis descent. The disorientation of Leydig cells and Sertoli cells in the adult testis may be the cause of spermatogenic dysfunction.

  14. Metabolism of di(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) in rats: in vivo and in vitro dose and time dependency of metabolism

    International Nuclear Information System (INIS)

    Lhuguenot, J.C.; Mitchell, A.M.; Milner, G.; Lock, E.A.; Elcombe, C.R.

    1985-01-01

    This study investigated the in vivo metabolism of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP) in rats after multiple dosing, the metabolism of MEHP in primary rat hepatocyte cultures for periods of up to 3 days, and the biotransformation of some major metabolites of MEHP. Rats were orally administered [ 14 C]DEHP or [ 14 C]MEHP at doses of 50 and 500 mg/kg body wt for three consecutive days. Urine was collected at 24-hr intervals, and metabolite profiles were determined. After a single dose of either compound, urinary metabolite profiles were similar to those previously reported. However, after multiple administration of both DEHP and MEHP at 500 mg/kg, increases in omega-/beta-oxidation products [metabolites I and V, mono(3-carboxy-2-ethylpropyl) phthalate and mono(5-carboxy-2-ethylpentyl) phthalate, respectively] and decreases in omega - 1-oxidation products [metabolites VI and IX, mono(2-ethyl-5-oxohexyl) phthalate and mono(2-ethyl-5-hydroxyhexyl) phthalate, respectively] were seen. At the low dose of 50 mg/kg little or no alteration in urinary metabolite profiles was observed. At 500 mg/kg of MEHP a 4-fold stimulation of CN- -insensitive palmitoyl-CoA oxidation (a peroxisomal beta-oxidation marker) was seen after three consecutive daily doses. At the low dose of 50 mg/kg only a 1.8-fold increase was noted. Similar observations were made with rat hepatocyte cultures. MEHP at concentrations of 50 and 500 microM was extensively metabolized in the rat hepatocyte cultures. Similar metabolic profiles to those seen after in vivo administration of MEHP were observed. At the high (500 microM) concentration of MEHP, changes in the relative proportions of omega- and omega- 1-oxidized metabolites were seen

  15. Observations related to hydrogen in powder and single crystal samples of YB2Cu3O7-δ

    International Nuclear Information System (INIS)

    Porath, D.; Grayevsky, A.; Kaplan, N.; Shaltiel, D.; Yaron, U.; Walker, E.

    1994-01-01

    New observations related to hydrogenation of YBa 2 Cu 3 O 7-δ (YBCO) are reported: (a) The effects of sample preparation on the H concentration in ''uncharged'' YBCO samples is investigated, and it is shown through nuclear magnetic resonance measurements that samples of YBCO prepared by ''standard'' solid-state reaction procedures may contain ab initio up to 0.2 atoms formula -1 of hydrogen. (b) It is demonstrated that one may introduce up to 0.3 atoms formula -1 into single crystal samples of YBCO without destroying the macroscopic crystal. The significance of the above observations is discussed briefly. (orig.)

  16. A single-ligand ultra-microporous MOF for precombustion CO2 capture and hydrogen purification.

    Science.gov (United States)

    Nandi, Shyamapada; De Luna, Phil; Daff, Thomas D; Rother, Jens; Liu, Ming; Buchanan, William; Hawari, Ayman I; Woo, Tom K; Vaidhyanathan, Ramanathan

    2015-12-01

    Metal organic frameworks (MOFs) built from a single small ligand typically have high stability, are rigid, and have syntheses that are often simple and easily scalable. However, they are normally ultra-microporous and do not have large surface areas amenable to gas separation applications. We report an ultra-microporous (3.5 and 4.8 Å pores) Ni-(4-pyridylcarboxylate)2 with a cubic framework that exhibits exceptionally high CO2/H2 selectivities (285 for 20:80 and 230 for 40:60 mixtures at 10 bar, 40°C) and working capacities (3.95 mmol/g), making it suitable for hydrogen purification under typical precombustion CO2 capture conditions (1- to 10-bar pressure swing). It exhibits facile CO2 adsorption-desorption cycling and has CO2 self-diffusivities of ~3 × 10(-9) m(2)/s, which is two orders higher than that of zeolite 13X and comparable to other top-performing MOFs for this application. Simulations reveal a high density of binding sites that allow for favorable CO2-CO2 interactions and large cooperative binding energies. Ultra-micropores generated by a small ligand ensures hydrolytic, hydrostatic stabilities, shelf life, and stability toward humid gas streams.

  17. Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

    Directory of Open Access Journals (Sweden)

    Jie Hong

    2017-09-01

    Full Text Available A series of single-hole hollow polyester fiber (SHHPF reinforced hydrogenated carboxyl nitrile rubber (HXNBR composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM, and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

  18. Positronium hydride in hydrogen-laden thermochemically reduced MgO single crystals

    International Nuclear Information System (INIS)

    Pareja, R.; la Cruz, R.M. de; Pedrosa, M.A.; Gonzalez, R.; Chen, Y.

    1990-01-01

    Thermochemical reduction of hydrogen-laden MgO single crystals at T∼2400 K results in a large concentration of both hydride (H - ) ions and anion vacancies (>10 24 m -3 ). Positron-lifetime experiments of these crystals provide evidence for bound positronium hydride states also referred to as [e + -H - ] or PsH states. The presence of the anion vacancies was found to inhibit the formation of these states. After thermally annealing out these vacancies, such that H - concentration remains intact, two long-lived components appear in the lifetime spectrum. Furthermore, these two components correlate with the presence of the H - ions. These results suggest the existence of bound [e + -H - ] states when positrons are trapped by the H - ions, and the subsequent formation of positronium (Ps) states by the dissociation of the [e + -H - ] states. From the values of the intermediate lifetime component, a value of (570±50) ps is obtained for the lifetime of the PsH state located in an anion vacancy in MgO. The longest lifetime component ∼(1--3) ns is attributed to pick-off annihilation of ortho-Ps states

  19. Positronium hydride in hydrogen-laden thermochemically reduced MgO single crystals

    Science.gov (United States)

    Pareja, R.; de La Cruz, R. M.; Pedrosa, M. A.; González, R.; Chen, Y.

    1990-04-01

    Thermochemical reduction of hydrogen-laden MgO single crystals at T~2400 K results in a large concentration of both hydride (H-) ions and anion vacancies (>1024 m-3). Positron-lifetime experiments of these crystals provide evidence for bound positronium hydride states also referred to as [e+-H-] or PsH states. The presence of the anion vacancies was found to inhibit the formation of these states. After thermally annealing out these vacancies, such that H- concentration remains intact, two long-lived components appear in the lifetime spectrum. Furthermore, these two components correlate with the presence of the H-ions. These results suggest the existence of bound [e+-H-] states when positrons are trapped by the H- ions, and the subsequent formation of positronium (Ps) states by the dissociation of the [e+-H-] states. From the values of the intermediate lifetime component, a value of (570+/-50) ps is obtained for the lifetime of the PsH state located in an anion vacancy in MgO. The longest lifetime component ~(1-3) ns is attributed to pick-off annihilation of ortho-Ps states.

  20. Deep levels due to hydrogen in ZnO single crystals

    Science.gov (United States)

    Parmar, Narendra; Weber, Marc; Lynn, Kelvin

    2009-05-01

    Hydrogen impurities and oxygen vacancies are involved in the ˜0.7 eV shift of the optical absorption edge of ZnO. Deuterium causes a smaller shift. Titanium metal is used to bind hydrogen as it diffuses out of ZnO. Positron annihilation spectroscopy coupled with other techniques point to the presence of oxygen vacancies. Removing hydrogen followed by annealing in oxygen reduces the carrier concentration.

  1. Determination of Phthalates in Drinking Water Samples

    African Journals Online (AJOL)

    user

    successfully applied to the analysis of phthalate esters contamination in bottled drinking water samples. ... esters are used in the manufacturing of polyvinyl chloride. (PVC). ... water, soil, air, food products and the human body. (Castillo et al.

  2. MEMS based impedimetric sensing of phthalates

    KAUST Repository

    Zia, Asif I.; Mohd. Syaifudin, A. R.; Mukhopadhyay, Subhas Chandra; Al-Bahadly, Ibrahim H.; Yu, Paklam; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen; Liao, Taishan

    2013-01-01

    Phthalate esters are known ubiquitous teratogenic and carcinogenic environmental and food pollutants. Their detection and quantification is strictly laboratory based, time consuming, expensive and professionally handled procedure. Presented research

  3. Data_files_Reyes_EHP_phthalates

    Data.gov (United States)

    U.S. Environmental Protection Agency — The file contains three files in comma separated values (.csv) format. “Reyes_EHP_Phthalates_US_metabolites.csv” contains information about the National Health and...

  4. Effect of high pressure hydrogen on the mechanical characteristics of single carbon fiber

    Science.gov (United States)

    Jeon, Sang Koo; Kwon, Oh Heon; Jang, Hoon-Sik; Ryu, Kwon Sang; Nahm, Seung Hoon

    2018-02-01

    In this study, carbon fiber was exposed to a pressure of 7 MPa for 24 h in high pressure chamber. The tensile test for carbon fiber was conducted to estimate the effect on the high pressure hydrogen in the atmosphere. To determine the tensile strength and Weibull modulus, approximately thirty carbon fiber samples were measured in all cases, and carbon fiber exposed to high pressure argon was evaluated to verify only the effect of hydrogen. Additionally, carbon fiber samples were annealed at 1950 °C for 1 h for a comparison with normal carbon fiber and then tested under identical conditions. The results showed that the tensile strength scatter of normal carbon fiber exposed to hydrogen was relatively wider and the Weibull modulus was decreased. Moreover, the tensile strength of the annealed carbon fiber exposed to hydrogen was increased, and these samples indicated a complex Weibull modulus because the hydrogen stored in the carbon fiber influenced the mechanical characteristic.

  5. Our Phthalate Research Spaning the 20th and 21st Centuries

    Science.gov (United States)

    •Hazard ID Studies •Studies to identify phthalates and other toxicants that disrupt fetal androgen function and postnatal reproductive development. Typically, a single high dose was used. • Studies with a postnatol assment of the male offspring through adult life o DEHP, BBP, ...

  6. An Experimental Investigation on Performance and Emissions of a Single Cylinder D.I Diesel Engine with Manifold Hydrogen Induction

    Directory of Open Access Journals (Sweden)

    Haroun A.K. Shahad

    2017-05-01

    Full Text Available Hydrogen is a clean fuel for internal combustion engines as it produces only water vapor and nitrogen oxides when it burns. In this research, hydrogen is used as a blending fuel with diesel to reduce pollutants emission and to improve performance. It is inducted in the inlet manifold, (continuous manifold induction, which is of a single cylinder, four stroke, direct injection, variable compression ratio water cold diesel engine, type (Kirloskar. This technique of hydrogen blending is selected because of its simplicity and low cost. Hydrogen blending is built on the basis of energy replacement. A special electronic unit is designed and fabricated to control hydrogen blending ratio. The maximum achieved ratio is 30% of input energy and beyond that the engine operation becomes unsatisfactory. Tests are done with 17.5 compression ratio and 1500 rpm. The brake specific fuel consumption is reduced by 29% and the engine thermal efficiency increased by 16% at these operating conditions. The pollutant emissions of carbon oxides, UHC, and smoke opacity are dramatically decreased by 19.5%, 13%,and 45% respectively while NOx emission increased by 10%.

  7. Identification of Zn-vacancy-hydrogen complexes in ZnO single crystals: A challenge to positron annihilation spectroscopy

    Science.gov (United States)

    Brauer, G.; Anwand, W.; Grambole, D.; Grenzer, J.; Skorupa, W.; Čížek, J.; Kuriplach, J.; Procházka, I.; Ling, C. C.; So, C. K.; Schulz, D.; Klimm, D.

    2009-03-01

    A systematic study of various, nominally undoped ZnO single crystals, either hydrothermally grown (HTG) or melt grown (MG), has been performed. The crystal quality has been assessed by x-ray diffraction, and a comprehensive estimation of the detailed impurity and hydrogen contents by inductively coupled plasma mass spectrometry and nuclear reaction analysis, respectively, has been made also. High precision positron lifetime experiments show that a single positron lifetime is observed in all crystals investigated, which clusters at 180-182 ps and 165-167 ps for HTG and MG crystals, respectively. Furthermore, hydrogen is detected in all crystals in a bound state with a high concentration (at least 0.3at.% ), whereas the concentrations of other impurities are very small. From ab initio calculations it is suggested that the existence of Zn-vacancy-hydrogen complexes is the most natural explanation for the given experimental facts at present. Furthermore, the distribution of H at a metal/ZnO interface of a MG crystal, and the H content of a HTG crystal upon annealing and time afterward has been monitored, as this is most probably related to the properties of electrical contacts made at ZnO and the instability in p -type conductivity observed at ZnO nanorods in literature. All experimental findings and presented theoretical considerations support the conclusion that various types of Zn-vacancy-hydrogen complexes exist in ZnO and need to be taken into account in future studies, especially for HTG materials.

  8. Hydrogen intercalation of single and multiple layer graphene synthesized on Si-terminated SiC(0001) surface

    International Nuclear Information System (INIS)

    Sołtys, Jakub; Piechota, Jacek; Ptasinska, Maria; Krukowski, Stanisław

    2014-01-01

    Ab initio density functional theory simulations were used to investigate the influence of hydrogen intercalation on the electronic properties of single and multiple graphene layers deposited on the SiC(0001) surface (Si-face). It is shown that single carbon layer, known as a buffer layer, covalently bound to the SiC substrate, is liberated after hydrogen intercalation, showing characteristic Dirac cones in the band structure. This is in agreement with the results of angle resolved photoelectron spectroscopy measurements of hydrogen intercalation of SiC-graphene samples. In contrast to that hydrogen intercalation has limited impact on the multiple sheet graphene, deposited on Si-terminated SiC surface. The covalently bound buffer layer is liberated attaining its graphene like structure and dispersion relation typical for multilayer graphene. Nevertheless, before and after intercalation, the four layer graphene preserved the following dispersion relations in the vicinity of K point: linear for (AAAA) stacking, direct parabolic for Bernal (ABAB) stacking and “wizard hat” parabolic for rhombohedral (ABCA) stacking

  9. Urinary phthalate monoesters and endometriosis in infertile Japanese women

    International Nuclear Information System (INIS)

    Itoh, Hiroaki; Iwasaki, Motoki; Hanaoka, Tomoyuki; Sasaki, Hiroshi; Tanaka, Tadao; Tsugane, Shoichiro

    2009-01-01

    Phthalates may act as an estrogen and are a potential risk factor for estrogen-related diseases such as endometriosis. We assessed the association between phthalate exposure and endometriosis in 166 consecutive women who presented at a university hospital for consultation regarding infertility. The subjects were interviewed and provided a urine specimen prior to a laparoscopic diagnosis of endometriosis. They were then categorized by the severity of endometriosis as controls (stages 0-I) and cases (stages II-IV). Urinary concentrations of the phthalate metabolites monoethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate were measured in 57 cases and 80 controls using high-performance liquid chromatography isotope-dilution tandem mass spectrometry. Adjusted odds ratios for endometriosis in relation to dichotomized individual phthalate metabolites (standardized for creatinine) were calculated. No significant association between endometriosis and any urinary creatinine-adjusted phthalate monoester was seen. Adjusted odds ratio (95% confidence interval) for higher dichotomized MEHP by endometriosis was 1.57 (0.74-3.30). No monotonic trend was seen in urinary creatinine-adjusted concentration of phthalate metabolites by endometriosis stage (p = 0.23-0.90). Our results do not support the hypothesis that higher urinary concentrations of phthalate metabolites are associated with the risk of endometriosis in infertile Japanese women.

  10. Urinary phthalate monoesters and endometriosis in infertile Japanese women

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Hiroaki [Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Iwasaki, Motoki, E-mail: moiwasak@ncc.go.jp [Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Hanaoka, Tomoyuki [Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Sasaki, Hiroshi; Tanaka, Tadao [Department of Obstetrics and Gynecology, Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo 105-8461 (Japan); Tsugane, Shoichiro [Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2009-12-15

    Phthalates may act as an estrogen and are a potential risk factor for estrogen-related diseases such as endometriosis. We assessed the association between phthalate exposure and endometriosis in 166 consecutive women who presented at a university hospital for consultation regarding infertility. The subjects were interviewed and provided a urine specimen prior to a laparoscopic diagnosis of endometriosis. They were then categorized by the severity of endometriosis as controls (stages 0-I) and cases (stages II-IV). Urinary concentrations of the phthalate metabolites monoethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate were measured in 57 cases and 80 controls using high-performance liquid chromatography isotope-dilution tandem mass spectrometry. Adjusted odds ratios for endometriosis in relation to dichotomized individual phthalate metabolites (standardized for creatinine) were calculated. No significant association between endometriosis and any urinary creatinine-adjusted phthalate monoester was seen. Adjusted odds ratio (95% confidence interval) for higher dichotomized MEHP by endometriosis was 1.57 (0.74-3.30). No monotonic trend was seen in urinary creatinine-adjusted concentration of phthalate metabolites by endometriosis stage (p = 0.23-0.90). Our results do not support the hypothesis that higher urinary concentrations of phthalate metabolites are associated with the risk of endometriosis in infertile Japanese women.

  11. Cleavage of hydrogen by activation at a single non-metal centre - towards new hydrogen storage materials.

    Science.gov (United States)

    Grabowski, Sławomir J

    2015-05-28

    Molecular surfaces of non-metal species are often characterized by both positive and negative regions of electrostatic potential (EP) at a non-metal centre. This centre may activate molecular hydrogen which further leads to the addition reaction. The positive EP regions at the non-metal centres correspond to σ-holes; the latter sites are enhanced by electronegative substituents. This is why the following simple moieties; PFH2, SFH, AsFH2, SeFH, BrF3, PF(CH3)2 and AsF(CH3)2, were chosen here to analyze the H2 activation and its subsequent splitting at the P, As, S, Se and Br centres. Also the reverse H-H bond reforming process is analyzed. MP2/aug-cc-pVTZ calculations were performed for systems corresponding to different stages of these processes. The sulphur centre in the SFH moiety is analyzed in detail since the potential barrier height for the addition reaction for this species is the lowest of the moieties analyzed here. The results of calculations show that the SFH + H2 → SFH3 reaction in the gas phase is endothermic but it is exothermic in polar solvents.

  12. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shwetha Ramkumar; Mahesh Iyer; Danny Wong; Himanshu Gupta; Bartev Sakadjian; Liang-Lhih Fan

    2008-09-30

    High purity hydrogen is commercially produced from syngas by the Water Gas Shift Reaction (WGSR) in high and low temperature shift reactors using iron oxide and copper catalysts respectively. However, the WGSR is thermodynamically limited at high temperatures towards hydrogen production necessitating excess steam addition and catalytic operation. In the calcium looping process, the equilibrium limited WGSR is driven forward by the incessant removal of CO{sub 2} by-product through the carbonation of calcium oxide. At high pressures, this process obviates the need for a catalyst and excess steam requirement, thereby removing the costs related to the procurement and deactivation of the catalyst and steam generation. Thermodynamic analysis for the combined WGS and carbonation reaction was conducted. The combined WGS and carbonation reaction was investigated at varying pressures, temperatures and S/C ratios using a bench scale reactor system. It was found that the purity of hydrogen increases with the increase in pressure and at a pressure of 300 psig, almost 100% hydrogen is produced. It was also found that at high pressures, high purity hydrogen can be produced using stoichiometric quantities of steam. On comparing the catalytic and non catalytic modes of operation in the presence of calcium oxide, it was found that there was no difference in the purity of hydrogen produced at elevated pressures. Multicyclic reaction and regeneration experiments were also conducted and it was found that the purity of hydrogen remains almost constant after a few cycles.

  13. Urinary phthalate and phthalate alternative metabolites and isoprostane among couples undergoing fertility treatment.

    Science.gov (United States)

    Wu, Haotian; Olmsted, Alexandra; Cantonwine, David E; Shahsavari, Shahin; Rahil, Tayyab; Sites, Cynthia; Pilsner, J Richard

    2017-02-01

    Epidemiological data suggest associations between phthalate exposures to a variety of adverse reproductive outcomes including reduced sperm quality and reproductive success. While mechanisms of these associations are not fully elucidated, oxidative stress has been implicated as a potential mediator. We examined associations of urinary metabolites of phthalates and phthalate alternative plasticizers with oxidative stress among couples seeking fertility treatment. Seventeen urinary plasticizer metabolites and 15-F2t isoprostane, a biomarker of oxidative stress, were quantified in spot samples from 50 couples seeking fertility treatment who enrolled in the Sperm Environmental Epigenetics and Development Study during 2014-2015. In multivariable analyses, percent change in isoprostane was positively associated with interquartile range increases for the oxidative metabolites of di-2-ethylhexyl phthalate, [mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP; 20.0%, p=0.02), mono-2-ethyl-5-oxohexyl phthalate (MEOHP; 24.1%, p=0.01), and mono-2-ethyl-5-carboxypentyl phthalate (MECPP; 24.1%, p=0.004)], mono-isobutyl phthalate (MiBP; 17.8%, p=0.02), mono-hydroxyisobutyl phthalate (MHiBP; 27.5%, p=0.003), and cyclohexane-1,2-dicarboxylic acid mono-hydroxy-isononyl ester (MHINCH; 32.3%, p=0.002). Stratification of participants by sex revealed that isoprostane was positively associated with MHiBP (41.4%, p=0.01) and monocarboxy-isononyl phthalate (MCNP; 26.0%, p=0.02) among females and MEOHP (35.8%, p=0.03), MiBP (29.2%, p=0.01), MHiBP (34.7%, p=0.007) and MHINCH (49.0%, p=0.002) among males. Our results suggest that exposure to phthalates and phthalate replacements are associated with higher levels of oxidative stress in a sex-specific manner. Additional studies are needed to replicate our findings and to examine the potential health implications of the use of phthalates and alternative phthalates in consumer end products. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Introducing molecular selectivity in rapid impedimetric sensing of phthalates

    KAUST Repository

    Zia, Asif I.; Mukhopadhyay, Subhas Chandra; Al-Bahadly, Ibrahim H.; Yu, Paklam; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2014-01-01

    This research article reports a real-time and non-invasive detection technique for phthalates in liquids by Electrochemical Impedance Spectroscopy (EIS), incorporating molecular imprinting technique to introduce selectivity for the phthalate

  15. Single Pot Selective Hydrogenation of Furfural to 2-Methylfuran Over Carbon Supported Iridium Catalysts

    KAUST Repository

    Date, Nandan S; Hengne, Amol Mahalingappa; Huang, Kuo-Wei; Chikate, Rajeev C.; Rode, C. V.

    2018-01-01

    Various iridium supported carbon catalysts were prepared and screened for direct hydrogenation of furfural (FFR) to 2-methyl furan (2-MF). Amongest these, 5% Ir/C showed excellent results with complete FFR conversion and highest selectivity of 95% to 2-MF at very low H2 pressure of 100 psig. Metallic (Iro) and oxide ( IrO2) phases of Ir catalyzed first step hydrogenation involving FFR to FAL and subsequent hydrogenation to 2-MF,respecively. This was confirmed by XPS analysis and some controlled experiments. At low temperature of 140 oC, almost equal selectivities of FAL (42%) and 2-MF (43%) were observed, while higher temperature (220oC) favored selective hydrodeoxygenation. At optimized temperature, 2-MF formed selectively while higher pressure and higher catalyst loading favored ring hydrogenation of furfural rather than side chain hydrogenation. With combination of several control experimental results and detailed catalyst characterization, a plausible reaction pathway has been proposed for selective formation of 2-MF. The selectivity to various other products in FFR hydrogenation can be manipulated by tailoring the reaction conditions over the same catalyst.

  16. Single Pot Selective Hydrogenation of Furfural to 2-Methylfuran Over Carbon Supported Iridium Catalysts

    KAUST Repository

    Date, Nandan S

    2018-03-20

    Various iridium supported carbon catalysts were prepared and screened for direct hydrogenation of furfural (FFR) to 2-methyl furan (2-MF). Amongest these, 5% Ir/C showed excellent results with complete FFR conversion and highest selectivity of 95% to 2-MF at very low H2 pressure of 100 psig. Metallic (Iro) and oxide ( IrO2) phases of Ir catalyzed first step hydrogenation involving FFR to FAL and subsequent hydrogenation to 2-MF,respecively. This was confirmed by XPS analysis and some controlled experiments. At low temperature of 140 oC, almost equal selectivities of FAL (42%) and 2-MF (43%) were observed, while higher temperature (220oC) favored selective hydrodeoxygenation. At optimized temperature, 2-MF formed selectively while higher pressure and higher catalyst loading favored ring hydrogenation of furfural rather than side chain hydrogenation. With combination of several control experimental results and detailed catalyst characterization, a plausible reaction pathway has been proposed for selective formation of 2-MF. The selectivity to various other products in FFR hydrogenation can be manipulated by tailoring the reaction conditions over the same catalyst.

  17. High urinary phthalate concentration associated with delayed pubarche in girls

    DEFF Research Database (Denmark)

    Frederiksen, H; Sørensen, K; Mouritsen, A

    2012-01-01

    Phthalates are a group of chemicals present in numerous consumer products. They have anti-androgenic properties in experimental studies and are suspected to be involved in human male reproductive health problems. A few studies have shown associations between phthalate exposure and changes...... and controls. We demonstrated that delayed pubarche, but not thelarche, was associated with high phthalate excretion in urine samples from 725 healthy school girls, which may suggest anti-androgenic actions of phthalates in our study group of girls....

  18. 40 CFR 721.10043 - Dineopentyl-4-substituted phthalate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dineopentyl-4-substituted phthalate... Specific Chemical Substances § 721.10043 Dineopentyl-4-substituted phthalate (generic). (a) Chemical... as dineopentyl-4-substituted phthalate (PMN P-02-697) is subject to reporting under this section for...

  19. Direct Observation of Double Hydrogen Transfer via Quantum Tunneling in a Single Porphycene Molecule on a Ag(110) Surface.

    Science.gov (United States)

    Koch, Matthias; Pagan, Mark; Persson, Mats; Gawinkowski, Sylwester; Waluk, Jacek; Kumagai, Takashi

    2017-09-13

    Quantum tunneling of hydrogen atoms (or protons) plays a crucial role in many chemical and biological reactions. Although tunneling of a single particle has been examined extensively in various one-dimensional potentials, many-particle tunneling in high-dimensional potential energy surfaces remains poorly understood. Here we present a direct observation of a double hydrogen atom transfer (tautomerization) within a single porphycene molecule on a Ag(110) surface using a cryogenic scanning tunneling microscope (STM). The tautomerization rates are temperature independent below ∼10 K, and a large kinetic isotope effect (KIE) is observed upon substituting the transferred hydrogen atoms by deuterium, indicating that the process is governed by tunneling. The observed KIE for three isotopologues and density functional theory calculations reveal that a stepwise transfer mechanism is dominant in the tautomerization. It is also found that the tautomerization rate is increased by vibrational excitation via an inelastic electron tunneling process. Moreover, the STM tip can be used to manipulate the tunneling dynamics through modification of the potential landscape.

  20. Effects of hydrogen on the single crystalline elastic constants of niobium

    Energy Technology Data Exchange (ETDEWEB)

    Schlader, Daniel Michael [Iowa State Univ., Ames, IA (United States)

    1977-06-01

    A special hydriding system was designed and constructed to satisfy conditions for hydriding niobium. This system controlled the temperature and hydrogen atmosphere surrounding the niobium while ultrasonic measurements were recorded. Ultrasonic wave velocities were determined by measurement of the times for ultrasonic pulses to transit and then echo through known dimensions of test specimens. The method which was employed is commonly known as the pulse-echo-overlap method. This study confirmed the general trends of earlier investigations. In this study C' continued to decrease and C44 continued to increase up to 4.69 atomic percent hydrogen which is the maximum concentration which has yet been examined. In the case of the niobium-hydrogen system the Snoek effect may well be a contributory factor to the decrease of C' with increasing hydrogen concentration. However, crystallographic considerations preclude this effect from contributing a concentration dependence to C44 or B. The observation of the present work implies that other factors must also be contributing to the overall behavior.

  1. Effects of hydrogen on the single crystalline elastic constants of niobium

    International Nuclear Information System (INIS)

    Schlader, D.M.

    1977-06-01

    A special hydriding system was designed and constructed to satisfy conditions for hydriding niobium. This system controlled the temperature and hydrogen atmosphere surrounding the niobium while ultrasonic measurements were recorded. Ultrasonic wave velocities were determined by measurement of the times for ultrasonic pulses to transit and then echo through known dimensions of test specimens. The method which was employed is commonly known as the pulse-echo-overlap method. This study confirmed the general trends of earlier investigations. In this study C' continued to decrease and C 44 continued to increase up to 4.69 atomic percent hydrogen which is the maximum concentration which has yet been examined. In the case of the niobium-hydrogen system the Snoek effect may well be a contributory factor to the decrease of C' with increasing hydrogen concentration. However, crystallographic considerations preclude this effect from contributing a concentration dependence to C 44 or B. The observation of the present work implies that other factors must also be contributing to the overall behavior

  2. Reactions of Hydrogen Sulfide with Singly and Doubly Tucked-in Titanocenes

    Czech Academy of Sciences Publication Activity Database

    Pinkas, Jiří; Císařová, I.; Horáček, Michal; Kubišta, Jiří; Mach, Karel

    2011-01-01

    Roč. 30, č. 5 (2011), s. 1034-1045 ISSN 0276-7333 R&D Projects: GA AV ČR IAA400400708; GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40400503 Keywords : hydrogen sulphide * titanocene * chemical structure Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.963, year: 2011

  3. DETERMINATION OF PHTHALATES FROM BOTTLED WATER BY GC-MS

    Directory of Open Access Journals (Sweden)

    IRINA DUMITRAȘCU

    2012-03-01

    Full Text Available Determination of phthalates from bottled water by GC-MS. Phthalates are ubiquitous pollutants in the environment, due to their widespread use in the last years. These compounds are used principally as plasticizers, to impact flexibility, workability and durability to polymers but they can also be found in products such as paints, adhesives, inks and cosmetics. Phthalates are not chemically bounded to polymers; hence they are easily released and migrate into foods, beverages and drinking water from the packaging or bottling materials or manufacturing processes. This process accelerates as plastic products age and break down. With respect to their endocrine disrupting potential, phthalates such as benzyl butyl phthalate (BBP, di-butyl phthalate (DBP and di-isobutyl phthalate (DIBP have been found to elicit estrogenic responses in in vitro assays. It is possible that phthalates are a contributory factor to endocrine-mediated adverse effects observed in wildlife and humans over the past few decades. In this experiment we have analyzed the phthalates from different bottled waters purchased from the market. Determination by gas chromatography in combination with mass spectrometry detector (GC–MS in electronic ionization mode (EI with selected-ion monitoring (SIM acquisition method (GC–MS (EI–SIM has been carried out. Methods have been developed for both qualitative and quantitative analysis of phthalates. The base peak (m/z = 149 of all the phthalates was selected for the screening studies. The characteristic ions of each compound were chosen for quantitative studies.

  4. Atomic hydrogen and oxygen adsorptions in single-walled zigzag silicon nanotubes

    International Nuclear Information System (INIS)

    Chen, Haoliang; Ray, Asok K.

    2013-01-01

    Ab initio calculations have been performed to study the electronic and geometric structure properties of zigzag silicon nanotubes. Full geometry and spin optimizations have been performed without any symmetry constraints with an all electron 3-21G* basis set and the B3LYP hybrid functional. The largest zigzag SiNT studied here, (12, 0), has a binding energy per atom of 3.584 eV. Atomic hydrogen and oxygen adsorptions on (9, 0) and (10, 0) nanotubes have also been studied by optimizing the distances of the adatoms from both inside and outside the tube. The adatom is initially placed in four adsorption sites-parallel bridge (PB), zigzag bridge (ZB), hollow, and on-top site. The on-top site is the most preferred site for hydrogen atom adsorbed on (9, 0), with an adsorption energy of 3.0 eV and an optimized distance of 1.49 Å from the adatom to the nearest silicon atom. For oxygen adsorption on (9, 0), the most preferred site is the ZB site, with an adsorption energy of 5.987 eV and an optimized distance of 1.72 Å. For atomic hydrogen adsorption on (10, 0), the most preferred site is also the on-top site with an adsorption energy of 3.174 eV and an optimized distance of 1.49 Å. For adsorption of atomic oxygen on (10, 0), the most preferred site is PB site, with an adsorption energy of 6.306 eV and an optimized distance of 1.71 Å. The HOMO–LUMO gaps of (9, 0) after adsorptions of hydrogen and oxygen atoms decrease while the HOMO–LUMO gaps of (10, 0) increase after adsorption of hydrogen and oxygen

  5. Special structures and properties of hydrogen nanowire confined in a single walled carbon nanotube at extreme high pressure

    Directory of Open Access Journals (Sweden)

    Yueyuan Xia

    2012-06-01

    Full Text Available Extensive ab initio molecular dynamics simulations indicate that hydrogen can be confined in single walled carbon nanotubes to form high density and high pressure H2 molecular lattice, which has peculiar shell and axial structures depending on the density or pressure. The band gap of the confined H2 lattice is sensitive to the pressure. Heating the system at 2000K, the H2 lattice is firstly melted to form H2 molecular liquid, and then some of the H2 molecules dissociate accompanied by drastic molecular and atomic reactions, which have essential effect on the electronic structure of the hydrogen system. The liquid hydrogen system at 2000K is found to be a particular mixed liquid, which consists of H2 molecules, H atoms, and H-H-H trimers. The dissociated H atoms and the trimers in the liquid contribute resonance electron states at the Fermi energy to change the material properties substantially. Rapidly cooling the system from 2000K to 0.01 K, the mixed liquid is frozen to form a mixed solid melt with a clear trend of band gap closure. It indicates that this solid melt may become a superconducting nanowire when it is further compressed.

  6. Hydrogen diffusion in a one domain. beta. -V sub 2 H single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Richter, D.; Mahling-Ennaoui, S. (Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)); Hempelmann, R. (Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Festkoerperforschung)

    1989-01-01

    The authors present first quasielastic neutron scattering experiments on hydrogen diffusion in a one-domain crystal of the ordered metal hydride {beta}-V{sub 2}H. The experiments led to a detailed evaluation of the microscopic jump geometries. At temperatures at which the structure is still intact the main diffusion channel leads across antistructural sites situated in empty layers in between occupied H-sheets. (orig.).

  7. 75 FR 18165 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates

    Science.gov (United States)

    2010-04-09

    ... investigated potential risks posed to children from phthalate plasticizers, especially di(2-ethylhexyl... be exposed to phthalates from many sources, including consumer products, food, cosmetics, medical... the potential health effects (including endocrine disrupting effects) of the full range of phthalates...

  8. Phthalates and Nonylphenols in Roskilde Fjord

    DEFF Research Database (Denmark)

    Vikelsøe, J.; Fauser, P.; Sørensen, P. B.

    The aim of the study has been to investigate the occurrence, sources, transport and fate of nonylphenols and phthalates in the aquatic environment of Roskilde Fjord. It was further intended to find the temporal as well as the spatial variation of these xenobiotics in the fjord and stream water...

  9. Analytical Chemical Control of Phthalates in Toys

    DEFF Research Database (Denmark)

    Rastogi, S. C.; Jensen, G. H.; Worsøe, I. M.

    The content of phthalates in toys and other articles for children up to 3 years of age is regulated by the Statutory Order of Danish Ministry of Environment and Energy, No. 151 of 15th March 1999. In the present investigation, 35 products (toys and other articles for children up to 3 years of age...

  10. Analytical Chemical Control of Phthalates in Toys

    DEFF Research Database (Denmark)

    Rastogi, S. C.; Worsøe, I. M.

    The content of phthalates in toys and other articles for children up to 3 years of age is regulated by the Statutory Order of Danish Ministry of Environment and Energy, No. 151 of 15th March 1999. In the present investigation, 20 products (toys and other articles for children up to 3 years of age...

  11. Surface deterioration of ammonium acid phthalate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Barrus, D.M.; Blake, R.L.; Burek, A.J.

    1976-01-01

    In working with various acid phthalate crystals for low energy X-ray spectroscopy, we have observed a relatively rapid surface degradation of ammonium acid phthalate in comparison with similar crystals was observed. It was found that two different samples degraded in a few days upon exposure to high vacuum (10/sup -6/ - 10/sup -7/ torr). The same crystals showed similar effects when exposed to room atmosphere for two to three weeks. One of these crystals deteriorated while kept constantly in a desiccator jar for about two years. The desiccator environment seems to be the most favorable. The observed difference in the surface of these crystals might be described as a change from a transparent, glasslike condition to a white, powderlike haze somewhat akin to frosted glass. A two week exposure to vacuum for a freshly cleaved crystal caused the integrated coefficient of reflection at 23.6 A to decrease by a factor of 2.5. The degraded surface areas tend to form definite rhombohedral patterns. Since the external symmetry of ammonium acid phthalate crystals is rhombohedral, this suggests that the degradation we observe takes place in the form of large etched figures. A possible mechanism may be sublimation, which would proceed more rapidly in vacuum than in air. It is concluded that ammonium acid phthalate should be kept in a desiccator environment as much as possible. Exposures to vacuum should be brief and critical diffraction measurements should be done using a freshly cleaved surface.

  12. Thermodynamics of single polyethylene and polybutylene glycols with hydrogen-bonding ends: A transition from looped to open conformations

    Science.gov (United States)

    Lee, Eunsang; Paul, Wolfgang

    2018-02-01

    A variety of linear polymer precursors with hydrogen bonding motifs at both ends enable us to design supramolecular polymer systems with tailored macroscopic properties including self-healing. In this study, we investigate thermodynamic properties of single polyethylene and polybutylene glycols with hydrogen bonding motifs. In this context, we first build a coarse-grained model of building blocks of the supramolecular polymer system based on all-atom molecular structures. The density of states of the single precursor is obtained using the stochastic approximation Monte Carlo method. Constructing canonical partition functions from the density of states, we find the transition from looped to open conformations at transition temperatures which are non-monotonously changing with an increasing degree of polymerization due to the competition between chain stiffness and loop-forming entropy penalty. In the complete range of chain length under investigation, a coexistence of the looped and open morphologies at the transition temperature is shown regardless of whether the transition is first-order-like or continuous. Polyethylene and polybutylene glycols show similar behavior in all the thermodynamic properties but the transition temperature of the more flexible polybutylene glycol is shown to change more gradually.

  13. Single and double acceptor-levels of a carbon-hydrogen defect in n-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Stübner, R.; Scheffler, L.; Kolkovsky, Vl., E-mail: kolkov@ifpan.edu.pl; Weber, J. [Technische Universität Dresden, 01062 Dresden (Germany)

    2016-05-28

    In the present study, we discuss the origin of two dominant deep levels (E42 and E262) observed in n-type Si, which is subjected to hydrogenation by wet chemical etching or a dc H-plasma treatment. Their activation enthalpies determined from Laplace deep level transient spectroscopy measurements are E{sub C}-0.06 eV (E42) and E{sub C}-0.51 eV (E262). The similar annealing behavior and identical depth profiles of E42 and E262 correlate them with two different charge states of the same defect. E262 is attributed to a single acceptor state due to the absence of the Poole-Frenkel effect and the lack of a capture barrier for electrons. The emission rate of E42 shows a characteristic enhancement with the electric field, which is consistent with the assignment to a double acceptor state. In samples with different carbon and hydrogen content, the depth profiles of E262 can be explained by a defect with one H-atom and one C-atom. From a comparison with earlier calculations [Andersen et al., Phys. Rev. B 66, 235205 (2002)], we attribute E42 to the double acceptor and E262 to the single acceptor state of the CH{sub 1AB} configuration, where one H atom is directly bound to carbon in the anti-bonding position.

  14. Hydrogen production with effluent from an ethanol–H2-coproducing fermentation reactor using a single-chamber microbial electrolysis cell

    KAUST Repository

    Lu, Lu

    2009-06-01

    Hydrogen can be produced by bacterial fermentation of sugars, but substrate conversion to hydrogen is incomplete. Using a single-chamber microbial electrolysis cell (MEC), we show that additional hydrogen can be produced from the effluent of an ethanol-type dark-fermentation reactor. An overall hydrogen recovery of 83 ± 4% was obtained using a buffered effluent (pH 6.7-7.0), with a hydrogen production rate of 1.41 ± 0.08 m3 H2/m3 reactor/d, at an applied voltage of Eap = 0.6 V. When the MEC was combined with the fermentation system, the overall hydrogen recovery was 96%, with a production rate of 2.11 m3 H2/m3/d, corresponding to an electrical energy efficiency of 287%. High cathodic hydrogen recoveries (70 ± 5% to 94 ± 4%) were obtained at applied voltages of 0.5-0.8 V due to shorter cycle times, and repression of methanogen growth through exposure of the cathode to air after each cycle. Addition of a buffer to the fermentation effluent was critical to MEC performance as there was little hydrogen production using unbuffered effluent (0.0372 m3 H2/m3/d at Eap = 0.6 V, pH 4.5-4.6). These results demonstrate that hydrogen yields from fermentation can be substantially increased by using MECs. © 2009 Elsevier B.V. All rights reserved.

  15. Protein hydrogen exchange measured at single-residue resolution by electron transfer dissociation mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper D; Zehl, Martin; Jensen, Ole Nørregaard

    2009-01-01

    Because of unparalleled sensitivity and tolerance to protein size, mass spectrometry (MS) has become a popular method for measuring the solution hydrogen (1H/2H) exchange (HX) of biologically relevant protein states. While incorporated deuterium can be localized to different regions by pepsin....... The deuterium labeling pattern of beta2-microglobulin is retained in the gaseous fragment ions by employing mild declustering conditions for electrospray ionization. A recently developed model peptide is used to arrive at such ion source declustering conditions that prevent the occurrence of intramolecular gas...

  16. Evidence for a single hydrogen molecule connected by an atomic chain

    DEFF Research Database (Denmark)

    Kiguchi, M.; Stadler, Robert; Bækgaard, Iben Sig Buur

    2007-01-01

    Stable, single-molecule conducting-bridge configurations are typically identified from peak structures in a conductance histogram. In previous work on Pt with H-2 at cryogenic temperatures it has been shown that a peak near 1G(0) identifies a single-molecule Pt-H-2-Pt bridge. The histogram shows...

  17. The association between phthalates in dust and allergic diseases among Bulgarian children

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Naydenov, Kiril Georgiev; Larsson, Martin

    2008-01-01

    BACKGROUND: Recent studies have identified associations between the concentration of phthalates in indoor dust and allergic symptoms in the airways, nose, and skin. OBJECTIVES: Our goal was to investigate the associations between allergic symptoms in children and the concentration of phthalate...... (controls). The dust samples were analyzed for their content of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP). RESULTS: A higher concentration of DEHP was found in homes...

  18. Thermally stable single atom Pt/m-Al2O3 for selective hydrogenation and CO oxidation

    KAUST Repository

    Zhang, Zailei

    2017-07-27

    Single-atom metal catalysts offer a promising way to utilize precious noble metal elements more effectively, provided that they are catalytically active and sufficiently stable. Herein, we report a synthetic strategy for Pt single-atom catalysts with outstanding stability in several reactions under demanding conditions. The Pt atoms are firmly anchored in the internal surface of mesoporous Al2O3, likely stabilized by coordinatively unsaturated pentahedral Al3+ centres. The catalyst keeps its structural integrity and excellent performance for the selective hydrogenation of 1,3-butadiene after exposure to a reductive atmosphere at 200 °C for 24 h. Compared to commercial Pt nanoparticle catalyst on Al2O3 and control samples, this system exhibits significantly enhanced stability and performance for n-hexane hydro-reforming at 550 °C for 48 h, although agglomeration of Pt single-atoms into clusters is observed after reaction. In CO oxidation, the Pt single-atom identity was fully maintained after 60 cycles between 100 and 400 °C over a one-month period.

  19. Influence of phthalates on cytokine production in monocytes and macrophages

    DEFF Research Database (Denmark)

    Hansen, Juliana Frohnert; Bendtzen, Klaus; Boas, Malene

    2015-01-01

    BACKGROUND: Phthalates are a group of endocrine disrupting chemicals suspected to influence the immune system. The aim of this systematic review is to summarise the present knowledge on the influence of phthalates on monocyte and macrophage production and secretion of cytokines, an influence which......://www.crd.york.ac.uk/NIHR_PROSPERO, registration number CRD42013004236). In vivo, ex vivo and in vitro studies investigating the influence of phthalates on cytokine mRNA expression and cytokine secretion in animals and humans were included. A total of 11 reports, containing 12 studies, were found eligible for inclusion. In these, a total of four...... different phthalate diesters, six primary metabolites (phthalate monoesters) and seven different cytokines were investigated. Though all studies varied greatly in study design and species sources, four out of five studies that investigated di-2-ethylhexyl phthalate found an increased tumour necrosis factor...

  20. Female exposure to phthalates and time to pregnancy

    DEFF Research Database (Denmark)

    Thomsen, Anne Marie L.; Riis, Anders H.; Olsen, Jørn

    2017-01-01

    STUDY QUESTION: Is female exposure to phthalate metabolites associated with reduced fecundity, as estimated by prolonged time to pregnancy (TTP)? SUMMARY ANSWER: Female exposure to monoethyl phthalate (MEP) but not monobutyl phthalate (MBP), monobenzyl phthalate (MBzP) and monoethylhexyl phthalate...... with prospective data based on 229 women from a Danish cohort of 430 first pregnancy planning couples enrolled in 1992-1994. In 2009, urinary analyses of phthalate metabolites were performed on stored urine samples from this cohort. PARTICIPANTS/MATERIALS, SETTING AND METHODS: We analyzed MEP, MBP, MBzP and MEHP...... to estimate fecundability ratios (FRs) and 95% CI in relation to the average urine metabolite concentration exposure level, controlled for age and BMI, and the time-varying variables smoking and alcohol. MAIN RESULT AND ROLE OF CHANCE: Urinary concentration of MEP was associated with a decreased fecundity...

  1. An Analysis of Cumulative Risks Indicated by Biomonitoring Data of Six Phthalates Using the Maximum Cumulative Ratio

    Science.gov (United States)

    The Maximum Cumulative Ratio (MCR) quantifies the degree to which a single component of a chemical mixture drives the cumulative risk of a receptor.1 This study used the MCR, the Hazard Index (HI) and Hazard Quotient (HQ) to evaluate co-exposures to six phthalates using biomonito...

  2. An analysis of cumulative risks based on biomonitoring data for six phthalates using the Maximum Cumulative Ratio

    Science.gov (United States)

    The Maximum Cumulative Ratio (MCR) quantifies the degree to which a single chemical drives the cumulative risk of an individual exposed to multiple chemicals. Phthalates are a class of chemicals with ubiquitous exposures in the general population that have the potential to cause ...

  3. Single cobalt sites in mesoporous N-doped carbon matrix for selective catalytic hydrogenation of nitroarenes

    KAUST Repository

    Sun, Xiaohui

    2017-11-20

    A supported cobalt catalyst with atomically dispersed Co-Nx sites (3.5 wt% Co) in a mesoporous N-doped carbon matrix (named Co@mesoNC) is synthesized by hydrolysis of tetramethyl orthosilicate (TMOS) in a Zn/Co bimetallic zeolitic imidazolate framework (BIMZIF(Co,Zn)), followed by high-temperature pyrolysis and SiO2 leaching. A combination of TEM, XRD XPS and X-ray absorption spectroscopy studies confirm the absence of cobalt nanoparticles and indicate that these highly dispersed cobalt species are present in the form of Co-Nx. The exclusive formation of Co-Nx sites in the carbon matrix is attributed to the presence of a large amount of Zn and N in the BIMZIF precursor together with the presence of SiO2 in the pore space of this framework, extending the initial spatial distance between cobalt atoms and thereby impeding their agglomeration. The presence of SiO2 during high-temperature pyrolysis is proven crucial to create mesoporosity and a high BET area and pore volume in the N-doped carbon support (1780 m2 g−1, 1.54 cm3 g−1). This heterogeneous Co@mesoNC catalyst displays high activity and selectivity (>99%) for the selective hydrogenation of nitrobenzene to aniline at mild conditions (0.5–3 MPa, 343–383 K). When more challenging substrates (functionalized nitroarenes) are hydrogenated, the catalyst Co@mesoNC displays an excellent chemoselectivity to the corresponding substituted anilines.The presence of mesoporosity improves mass transport of reactants and/or products and the accessibility of the active Co-Nx sites, and greatly reduces deactivation due to fouling.

  4. Single cobalt sites in mesoporous N-doped carbon matrix for selective catalytic hydrogenation of nitroarenes

    KAUST Repository

    Sun, Xiaohui; Olivos-Suarez, Alma I.; Osadchii, Dmitrii; Romero, Maria Jose Valero; Kapteijn, Freek; Gascon, Jorge

    2017-01-01

    A supported cobalt catalyst with atomically dispersed Co-Nx sites (3.5 wt% Co) in a mesoporous N-doped carbon matrix (named Co@mesoNC) is synthesized by hydrolysis of tetramethyl orthosilicate (TMOS) in a Zn/Co bimetallic zeolitic imidazolate framework (BIMZIF(Co,Zn)), followed by high-temperature pyrolysis and SiO2 leaching. A combination of TEM, XRD XPS and X-ray absorption spectroscopy studies confirm the absence of cobalt nanoparticles and indicate that these highly dispersed cobalt species are present in the form of Co-Nx. The exclusive formation of Co-Nx sites in the carbon matrix is attributed to the presence of a large amount of Zn and N in the BIMZIF precursor together with the presence of SiO2 in the pore space of this framework, extending the initial spatial distance between cobalt atoms and thereby impeding their agglomeration. The presence of SiO2 during high-temperature pyrolysis is proven crucial to create mesoporosity and a high BET area and pore volume in the N-doped carbon support (1780 m2 g−1, 1.54 cm3 g−1). This heterogeneous Co@mesoNC catalyst displays high activity and selectivity (>99%) for the selective hydrogenation of nitrobenzene to aniline at mild conditions (0.5–3 MPa, 343–383 K). When more challenging substrates (functionalized nitroarenes) are hydrogenated, the catalyst Co@mesoNC displays an excellent chemoselectivity to the corresponding substituted anilines.The presence of mesoporosity improves mass transport of reactants and/or products and the accessibility of the active Co-Nx sites, and greatly reduces deactivation due to fouling.

  5. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage

    Energy Technology Data Exchange (ETDEWEB)

    Mahesh Iyer; Shwetha Ramkumar; Liang-Shih Fan

    2006-09-30

    Enhancement in the production of high purity hydrogen from fuel gas, obtained from coal gasification, is limited by thermodynamics of the Water Gas Shift Reaction. However, this constraint can be overcome by concurrent water-gas shift (WGS) and carbonation reactions to enhance H{sub 2} production by incessantly driving the equilibrium-limited WGS reaction forward and in-situ removing the CO2 product from the gas mixture. The spent sorbent is then regenerated by calcining it to produce a pure stream of CO{sub 2} and CaO which can be reused. However while performing the cyclic carbonation and calcination it was observed that the CO{sub 2} released during the in-situ calcination causes the deactivation of the iron oxide WGS catalyst. Detailed understanding of the iron oxide phase diagram helped in developing a catalyst pretreatment procedure using a H{sub 2}/H{sub 2}O system to convert the deactivated catalyst back to its active magnetite (Fe{sub 3}O{sub 4}) form. The water gas shift reaction was studied at different temperatures, different steam to carbon monoxide ratios (S/C) 3:1, 2:1, 1:1 and different total pressures ranging from 0-300 psig. The combined water gas shift and carbonation reaction was investigated at temperatures ranging from 600-700C, S/C ratio of 3:1 to 1:1 and at different pressures of 0-300 psig and the calcium looping process was found to produce high purity hydrogen with in-situ CO{sub 2} capture.

  6. Catalytic activity of Pd-doped Cu nanoparticles for hydrogenation as a single-atom-alloy catalyst.

    Science.gov (United States)

    Cao, Xinrui; Fu, Qiang; Luo, Yi

    2014-05-14

    The single atom alloy of extended surfaces is known to provide remarkably enhanced catalytic performance toward heterogeneous hydrogenation. Here we demonstrate from first principles calculations that this approach can be extended to nanostructures, such as bimetallic nanoparticles. The catalytic properties of the single-Pd-doped Cu55 nanoparticles have been systemically examined for H2 dissociation as well as H atom adsorption and diffusion, following the concept of single atom alloy. It is found that doping a single Pd atom at the edge site of the Cu55 shell can considerably reduce the activation energy of H2 dissociation, while the single Pd atom doped at the top site or in the inner layers is much less effective. The H atom adsorption on Cu55 is slightly stronger than that on the Cu(111) surface; however, a larger nanoparticle that contains 147 atoms could effectively recover the weak binding of the H atoms. We have also investigated the H atom diffusion on the 55-atom nanoparticle and found that spillover of the produced H atoms could be a feasible process due to the low diffusion barriers. Our results have demonstrated that facile H2 dissociation and weak H atom adsorption could be combined at the nanoscale. Moreover, the effects of doping one more Pd atom on the H2 dissociation and H atom adsorption have also been investigated. We have found that both the doping Pd atoms in the most stable configuration could independently exhibit their catalytic activity, behaving as two single-atom-alloy catalysts.

  7. Phthalate exposure and high blood pressure in adults: a cross-sectional study in China.

    Science.gov (United States)

    Zhang, Shao-Hui; Shen, Ya-Xin; Li, Lin; Fan, Tong-Tong; Wang, Yan; Wei, Ning

    2018-03-27

    Widespread phthalate exposure has been recently documented and is hypothesized to increase blood pressure (BP) in humans. However, current studies have provided inconclusive evidence for an association between phthalate exposure and BP. Human epidemiologic studies on the topic remain lacking. Therefore, this study aims to examine the association between serum phthalate concentrations and BP in a Chinese population. We measured several parameters of BP (systolic BP, diastolic BP, total cholesterol, and triglyceride) and the concentrations of 16 phthalates (dimethyl phthalate (DMP), diethyl phthalate, diisobutyl phthalate, dibutyl phthalate (DBP), bis (2-methoxyethyl) phthalate, bis (4-methyl-2-pentyl) phthalate, bis (2-ethoxyethyl) phthalate, diamyl phthalate, dihexyl phthalate, benzyl butyl phthalate, bis (2-nbutoxyethyl) phthalate (DBEP), dicyclohexyl phthalate, bis (2-ethyl hexyl) phthalate (DEHP), diisononyl phthalate, diphenyl phthalate, and di-n-octyl phthalate) in the serum of 474 adults recruited from a primary health care clinic. The relationship between serum phthalate concentrations and BP parameters was assessed with multivariate linear regressions. DBP was the most ubiquitous and dominant contaminant in the study population. The systolic BP of subjects in the median-exposure DEHP group significantly increased by 2.96 mmHg (p < 0.05) relative to that of subjects in the low-exposure group. Significant positive dose-related associations of DMP and DBEP with the levels of total cholesterol in serum (p for trend < 0.05) were also found. These associations persisted even when considering exposure to multiple phthalates. Our results suggested that phthalate exposure might increase BP in adults. However, our findings warrant further studies in a larger and more general population.

  8. Phthalate exposure and childrens neurodevelopment: A systematic review

    International Nuclear Information System (INIS)

    Ejaredar, Maede; Nyanza, Elias C.; Ten Eycke, Kayla; Dewey, Deborah

    2015-01-01

    Background: Emerging evidence from observational studies suggests that prenatal exposure to phthalates affects neurodevelopment in children. Objective: To conduct a systematic review of the existing literature on the association between urinary phthalate concentrations and children's neurodevelopment. Methods: We searched electronic bibliographic databases (MEDLINE, PubMed, EMBASE, PsycINFO, CINAHL, Global Health, CAB abstracts, and ERIC) (1910 to February 21st, 2014); reference lists of included articles, and conference abstracts (American Psychiatric Association, American Academy of Neurology, and Pediatric Academic Societies). Two independent reviewers screened abstracts and extracted data. We included original studies reporting on the association between prenatal or childhood urinary phthalate metabolites, and cognitive and behavioral outcomes (e.g., IQ scores, BASC-2 scores or equivalent) in children 0–12 years of age. Results: Of 2804 abstracts screened, 11 original articles met our criteria for inclusion. Conclusions: A systematic review of the literature supports the contention that prenatal exposure phthalates is associated with adverse cognitive and behavioral outcomes in children, including lower IQ, and problems with attention, hyperactivity, and poorer social communication. Further research characterizing the associations between specific phthalate metabolites and children's neurodevelopmental outcomes is needed to support the development of mitigation strategies and enhance the development of appropriate health policy. - Highlights: • Prenatal maternal urinary concentrations of phthalate metabolites appear to be associated with adverse cognitive and behavioral outcomes in children. • Both low molecular weight (e.g., monobutyl phthalate, MBP) and high molecular weight (e.g., di(2-ethylhexyl) phthalate, DEHP) phthalate metabolites are associated with adverse cognitive and behavioral outcomes. • Sex-specific effects from phthalate

  9. Phthalate exposure and childrens neurodevelopment: A systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Ejaredar, Maede, E-mail: mejareda@ucalgary.ca [Department of Community Health Sciences, University of Calgary, Calgary, Alberta (Canada); Nyanza, Elias C. [Department of Community Health Sciences, University of Calgary, Calgary, Alberta (Canada); Ten Eycke, Kayla [Behavioral Research Unit, Department of Paediatrics, University of Calgary, Calgary, Alberta (Canada); Dewey, Deborah [Department of Community Health Sciences, University of Calgary, Calgary, Alberta (Canada); Behavioral Research Unit, Department of Paediatrics, University of Calgary, Calgary, Alberta (Canada); Alberta Children' s Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta (Canada)

    2015-10-15

    Background: Emerging evidence from observational studies suggests that prenatal exposure to phthalates affects neurodevelopment in children. Objective: To conduct a systematic review of the existing literature on the association between urinary phthalate concentrations and children's neurodevelopment. Methods: We searched electronic bibliographic databases (MEDLINE, PubMed, EMBASE, PsycINFO, CINAHL, Global Health, CAB abstracts, and ERIC) (1910 to February 21st, 2014); reference lists of included articles, and conference abstracts (American Psychiatric Association, American Academy of Neurology, and Pediatric Academic Societies). Two independent reviewers screened abstracts and extracted data. We included original studies reporting on the association between prenatal or childhood urinary phthalate metabolites, and cognitive and behavioral outcomes (e.g., IQ scores, BASC-2 scores or equivalent) in children 0–12 years of age. Results: Of 2804 abstracts screened, 11 original articles met our criteria for inclusion. Conclusions: A systematic review of the literature supports the contention that prenatal exposure phthalates is associated with adverse cognitive and behavioral outcomes in children, including lower IQ, and problems with attention, hyperactivity, and poorer social communication. Further research characterizing the associations between specific phthalate metabolites and children's neurodevelopmental outcomes is needed to support the development of mitigation strategies and enhance the development of appropriate health policy. - Highlights: • Prenatal maternal urinary concentrations of phthalate metabolites appear to be associated with adverse cognitive and behavioral outcomes in children. • Both low molecular weight (e.g., monobutyl phthalate, MBP) and high molecular weight (e.g., di(2-ethylhexyl) phthalate, DEHP) phthalate metabolites are associated with adverse cognitive and behavioral outcomes. • Sex-specific effects from phthalate

  10. RBS/channeling analysis of hydrogen-implanted single crystals of FZ silicon and 6H silicon

    International Nuclear Information System (INIS)

    Irwin, R.B.

    1984-01-01

    Single crystals of FZ silicon and 6H silicon carbide were implanted with hydrogen ions (50 and 80 keV, respectively) to fluences from 2 x 10 16 H + /cm 2 to 2 x 10 18 H+/cm 2 . The implantations were carried out at three temperatures: approx.95K, 300 K, and approx.800 K. Swelling of the samples was measured by surface profilometry. RBS/channeling was used to obtain the damage profiles and to determine the amount of hydrogen retained in the lattice. The damage profiles are centered around X/sub m/ for the implants into silicon and around R/sub p/ for silicon carbide. For silicon carbide implanted at 95 K and 300 K and for silicon implanted at 95 K, the peak damage region is amorphous for fluences above 8 x 10 16 H + /cm 2 , 4 x 10 17 H + /cm 2 , and 2 x 10 17 H + /cm 2 , respectively. Silicon implanted at 300 and 800 K and silicon carbide implanted at 800 K remain crystalline up to fluences of 1 x 10 18 H + /cm 2 . The channeling damage results agree with previously reported TEM and electron diffraction data. The predictions of a simple disorder-accumulation model with a linear annealing term explains qualitatively the observed damage profiles in silicon carbide. Quantitatively, however, the model predicts faster development of the damage profiles than is observed at low fluences in both silicon and silicon carbide. For samples implanted at 300 and 800 K, the model also predicts substantially less peak disorder than is observed. The effect of the surface, the retained hydrogen, the shape of S/sub D/(X), and the need for a nonlinear annealing term may be responsible for the discrepancy

  11. Phthalates and polybrominated diphenyl ethers in retail stores

    Science.gov (United States)

    Xu, Ying; Liang, Yirui; Urquidi, Jorge R.; Siegel, Jeffrey A.

    2014-04-01

    Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories, because they are extensively used as additives in consumer products and associated with serious health concerns. This study measured six phthalate and 14 PBDE compounds inside of 12 retail stores in Texas and Pennsylvania, U.S. Phthalates and PBDEs were widely found in the retail environment, indicating that they are ubiquitous indoor air pollutants. DEP, DnBP, and DEHP were the most abundant phthalates, with DnBP showing the highest concentration (0.23 ± 0.36 μg m-3). PBDEs were dominated by BDE-28, -99, and -209, having concentrations as high as 0.85 ± 1.99 ng m-3 (BDE-99). The levels of phthalates and PBDEs measured in this study are comparable to concentrations found in previous investigations of residential buildings, with phthalates showing lower concentrations and PBDEs exhibiting higher concentrations in retail stores. The potential co-occurrence of phthalates was not as strong as that of PBDEs, suggesting that phthalates might have more diverse sources. Whole building emission rates were calculated and showed similar patterns of variations as indoor air concentrations, suggestion the diversity of indoor sources of phthalates and PBDEs in retail environments.

  12. A monograph on the remediation of hazardous phthalates.

    Science.gov (United States)

    Benjamin, Sailas; Pradeep, Selvanesan; Josh, Moolakkariyil Sarath; Kumar, Sunil; Masai, Eiji

    2015-11-15

    Phthalates or phthalic acid esters are a group of xenobiotic and hazardous compounds blended in plastics to enhance their plasticity and versatility. Enormous quantities of phthalates are produced globally for the production of plastic goods, whose disposal and leaching out into the surroundings cause serious concerns to the environment, biota and human health. Though in silico computational, in vitro mechanistic, pre-clinical animal and clinical human studies showed endocrine disruption, hepatotoxic, teratogenic and carcinogenic properties, usage of phthalates continues due to their cuteness, attractive chemical properties, low production cost and lack of suitable alternatives. Studies revealed that microbes isolated from phthalate-contaminated environmental niches efficiently bioremediate various phthalates. Based upon this background, this review addresses the enumeration of major phthalates used in industry, routes of environmental contamination, evidences for health hazards, routes for in situ and ex situ microbial degradation, bacterial pathways involved in the degradation, major enzymes involved in the degradation process, half-lives of phthalates in environments, etc. Briefly, this handy module would enable the readers, environmentalists and policy makers to understand the impact of phthalates on the environment and the biota, coupled with the concerted microbial efforts to alleviate the burden of ever increasing load posed by phthalates. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Annealing and surface conduction on Hydrogen peroxide treated bulk melt-grown, single crystal ZnO

    International Nuclear Information System (INIS)

    Mtangi, W.; Nel, J.M.; Auret, F.D.; Chawanda, A.; Diale, M.; Nyamhere, C.

    2012-01-01

    We report on the studies carried out on hydrogen peroxide treated melt-grown, bulk single crystal ZnO samples. Results show the existence of two shallow donors in the as-received ZnO samples with energy levels (37.8±0.3) meV that has been suggested as Zn i related and possibly H-complex related and (54.5±0.9) meV, which has been assigned to an Al-related donor. Annealing studies performed on the hydrogen peroxide treated samples reveal the existence of a conductive channel in the samples in which new energy levels have been observed, Zn vacancies, related to the Group I elements, X Zn . The surface donor volume concentration of the conductive channel was calculated from a theory developed by Look (2007) . Results indicate an increase in the surface volume concentration with increasing annealing temperature from 60×10 17 cm −3 at 200 °C to 4.37×10 18 cm -3 at 800 °C.

  14. Annealing and surface conduction on Hydrogen peroxide treated bulk melt-grown, single crystal ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Mtangi, W., E-mail: wilbert.mtangi@up.ac.za [University of Pretoria, Physics Department, Pretoria 0002 (South Africa); Nel, J.M.; Auret, F.D.; Chawanda, A.; Diale, M. [University of Pretoria, Physics Department, Pretoria 0002 (South Africa); Nyamhere, C. [Nelson Mandela Metropolitan University, Physics Department, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2012-05-15

    We report on the studies carried out on hydrogen peroxide treated melt-grown, bulk single crystal ZnO samples. Results show the existence of two shallow donors in the as-received ZnO samples with energy levels (37.8{+-}0.3) meV that has been suggested as Zn{sub i} related and possibly H-complex related and (54.5{+-}0.9) meV, which has been assigned to an Al-related donor. Annealing studies performed on the hydrogen peroxide treated samples reveal the existence of a conductive channel in the samples in which new energy levels have been observed, Zn vacancies, related to the Group I elements, X{sub Zn}. The surface donor volume concentration of the conductive channel was calculated from a theory developed by Look (2007) . Results indicate an increase in the surface volume concentration with increasing annealing temperature from 60 Multiplication-Sign 10{sup 17} cm{sup -3} at 200 Degree-Sign C to 4.37 Multiplication-Sign 10{sup 18} cm{sup -3} at 800 Degree-Sign C.

  15. Effect of hydrogen on the growth and morphology of single wall carbon nanotubes synthesized on a Fe-Mo/MgO catalytic system

    Energy Technology Data Exchange (ETDEWEB)

    Biris, Alexandru R. [National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, RO-3400 (Romania)], E-mail: biris@oc1.itim-cj.ro; Li Zhongrui; Dervishi, Enkeleda [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Lupu, Dan [National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, RO-3400 (Romania); Xu Yang; Saini, Viney [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Watanabe, Fumiya [Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Biris, Alexandru S. [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States)], E-mail: asbiris@ualr.edu

    2008-04-21

    Single wall carbon nanotubes were synthesized from thermal pyrolysis of methane on a Fe-Mo/MgO catalyst by radio frequency catalytic chemical vapor deposition (RF-CVD) using argon as a carrier gas. Controlled amounts of hydrogen (H{sub 2}/CH{sub 4}=0-1 v/v) were introduced in separate experiments along with the carbon source. The properties and morphology of the synthesized single wall carbon nanotubes were monitored by transmission electron microscopy, Raman scattering, and thermogravimetric analysis. The nanotubes with the highest crystallinity were obtained with H{sub 2}/CH{sub 4}=0.6. By monitoring the Radial Breathing Modes present in the Raman spectra of the single-wall carbon nanotube samples, the variation of the structural and morphological properties of the carbon nanotubes with the flow level of hydrogen, reflect changes of the catalyst systems induced by the presence of hydrogen.

  16. Growth of colonies and hyphal ultrastructure of filamentous fungi grown on dibutyl phthalate and di(2-ethylhexyl)phthalate

    OpenAIRE

    Suárez-Segundo, J.L.; Vázquez-López, D.; Torres-García, J.L.; Ahuactzin-Perez, M.; Montiel-Martínez, N.; Tlecuitl-Beristain, S.; Sánchez, C.

    2013-01-01

    Phthalates are compounds that give fl exnbíüty to the plastics and are considered mutagens and teratogens. Mycelial growth rate, biomass production and hyphal diameter of the young and mature zones of colonies of Fusarium oxysporum, Mortierella alpina, Pleurotuspulmonarius, two strains of Pleurotus ostreatus (Po 37 and Po 83) and one strain of Pleurotus florida grown on glucose, di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate were studied. F oxysporum had the highest mycelial growth r...

  17. Phthalate and non-phthalate plasticizers in indoor dust from childcare facilities, salons, and homes across the USA.

    Science.gov (United States)

    Subedi, Bikram; Sullivan, Kenneth D; Dhungana, Birendra

    2017-11-01

    The quality of indoor environment has received considerable attention owing to the declining outdoor human activities and the associated public health issues. The prolonged exposure of children in childcare facilities or the occupational exposure of adults to indoor environmental triggers can be a culprit of the pathophysiology of several commonly observed idiopathic syndromes. In this study, concentrations of potentially toxic plasticizers (phthalates as well as non-phthalates) were investigated in 28 dust samples collected from three different indoor environments across the USA. The mean concentrations of non-phthalate plasticizers [acetyl tri-n-butyl citrate (ATBC), di-(2-ethylhexyl) adipate (DEHA), and di-isobutyl adipate (DIBA)] were found at 0.51-880 μg/g for the first time in indoor dust samples from childcare facilities, homes, and salons across the USA. The observed concentrations of these replacement non-phthalate plasticizer were as high as di-(2-ethylhexyl) phthalate, the most frequently detected phthalate plasticizer at highest concentration worldwide, in most of indoor dust samples. The estimated daily intakes of total phthalates (n = 7) by children and toddlers through indoor dust in childcare facilities were 1.6 times higher than the non-phthalate plasticizers (n = 3), whereas estimated daily intake of total non-phthalates for all age groups at homes were 1.9 times higher than the phthalate plasticizers. This study reveals, for the first time, a more elevated (∼3 folds) occupational intake of phthalate and non-phthalate plasticizers through the indoor dust at salons (214 and 285 ng/kg-bw/day, respectively) than at homes in the USA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A Room-temperature Hydrogen Gas Sensor Using Palladium-decorated Single-Walled Carbon Nanotube/Si Heterojunction

    Directory of Open Access Journals (Sweden)

    Yong Gang DU

    2016-05-01

    Full Text Available We report a room-temperature (RT hydrogen gas (H2 sensor based on palladium-decorated single-walled carbon nanotube/Si (Pd-SWNTs/Si heterojunction. The current-voltage (I-V curves of the Pd-SWNTs/Si heterojunction in different concentrations of H2 were measured. The experimental results reveal that the Pd-SWNTs/Si heterojunction exhibits high H2 response. After exposure to 0.02 %, 0.05 %, and 0.1 % H2 for 10 min, the resistance of the heterojunction increases dramatically. The response is 122 %, 269 % and 457 %, respectively. A simple interfacial theory is used to understand the gas sensitivity results. This approach is a step toward future CNTs-based gas sensors for practical application.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12925

  19. Magnetic properties of a hydrogenation-extracted UCoSn single crystal

    Czech Academy of Sciences Publication Activity Database

    Kolomiets, A.; Andreev, Alexander V.; Havela, L.

    2009-01-01

    Roč. 471, 1-2 (2009), s. 21-23 ISSN 0925-8388 R&D Projects: GA MŠk OC 144 Institutional research plan: CEZ:AV0Z10100520 Keywords : uranium intermetallics * single crystal * ferromagnetism * hydrides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.135, year: 2009

  20. Determination of contamination pathways of phthalates in food products sold on the Belgian market.

    Science.gov (United States)

    Van Holderbeke, Mirja; Geerts, Lieve; Vanermen, Guido; Servaes, Kelly; Sioen, Isabelle; De Henauw, Stefaan; Fierens, Tine

    2014-10-01

    As numerous studies have indicated that food ingestion is the most important exposure pathway to several phthalates, this study aimed to determine possible contamination pathways of phthalates in food products sold on the Belgian market. To do this, concentrations of eight phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP)) were determined in 591 foods and 30 packaging materials. In general, the four most prominent phthalates in Belgian food products were DEHP, DiBP, DnBP and BBP. Special attention was given to the origin of these phthalates in bread, since high phthalate concentrations (especially DEHP) were determined in this frequently consumed food product. Phthalates seemed to occur in Belgian bread samples due to the use of contaminated ingredients (i.e. use of contaminated flour) as well as due to migration from phthalate containing contact materials used during production (e.g. coated baking trays). Also the results of the conducted concentration profiles of apple, bread, salami and two cheese types revealed the important role of processing - and not packaging - on phthalate contents in foods. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Growth and characterization of calcium hydrogen phosphate dihydrate crystals from single diffusion gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, K.; Dale Keefe, C. [Department of Chemistry, Cape Breton University, Sydney, Nova Scotia (Canada)

    2010-09-15

    Calcium hydrogen phosphate dihydrate (CaHPO{sub 4}.2H{sub 2}O, CHPD) a dissolved mineral in urine is known to cause renal or bladder stones in both human and animals. Growth of CHPD or brushite using sodium metasilicate gel techniques followed by light and polarizing microscopic studies revealed its structural and morphological details. Crystal identity by powder x-ray diffraction confirmed the FT-IR and FT-Raman spectroscopic techniques as alternate methods for fast analysis of brushite crystals which could form as one type of renal stones. P-O-P asymmetric stretchings in both FT-IR (987.2, 874.1 and 792 cm{sup -1}) and FT-Raman (986.3 cm{sup -1}, 1057.6 cm{sup -1} and 875.2 cm{sup -1}) were found as characteristics of brushite crystals. Differential Scanning Calorimetry (DSC) analysis revealed brushite crystallization purity using gel method by studying their endothermic peaks. This study incorporated a multidisciplinary approach in characterizing CHPD crystals grown in vitro to help formulate prevention or dissolution strategy in controlling urinary stone growth. Initial studies with 0.2 M citric acid ions as controlling agent in the nucleation of brushite crystals further support the presented approach. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Possible mechanism of phthalates-induced tumorigenesis

    Directory of Open Access Journals (Sweden)

    Yu-Chih Wang

    2012-07-01

    Full Text Available Phthalates—substances used in the manufacture of plastics—are considered as possible human carcinogens and tumor-promoting agents. The worldwide annual production of plastics surpassed 300 million tons in 2010. Plastics are an indispensable material in modern society, and many products manufactured from plastics are a boon to public health; however, plastics also pose health risks. Animal studies have indicated that phthalates are carcinogenic, but human epidemiological data confirming this carcinogenicity in humans are limited. The activation of peroxisome proliferator-activated receptor α (PPARα, which has been observed in rodent carcinogenesis, has not been observed in humans. Here, we review the hypothesis that the aryl hydrocarbon receptor (AhR and its downstream signaling cascade promote phthalate-induced tumorigenesis.

  3. Adsorption of Phthalates on Municipal Activated Sludge

    Directory of Open Access Journals (Sweden)

    Hongbo Wang

    2017-01-01

    Full Text Available Phthalates (PAEs are commonly detected in discharge of municipal wastewater treatment plants. This study investigated the removal of six typical PAEs with activated sludge and the results revealed that concentrations of aqueous PAEs decreased rapidly during the beginning 15 min and reached equilibrium within 2 hours due to the adsorption of activated sludge. The process followed first-order kinetic equation, except for dioctyl phthalate (DOP. The factors influencing the adsorption were also evaluated and it was found that higher initial concentrations of PAEs enhanced the removal but affected little the adsorption equilibrium time. The adsorption of PAEs favored lower operating temperature (the optimum temperature was approximately 25°C in this research, which could be an exothermic process. Additionally, lower aqueous pH could also benefit the adsorption.

  4. Single- and double-electron detachment in collisions of two negative hydrogen ions

    International Nuclear Information System (INIS)

    Melchert, F.; Schulze, R.; Kruedener, S.; Meuser, S.; Salzborn, E.

    1995-01-01

    Employing the crossed-beams technique in conjunction with a beam-pulsing method, we have measured absolute cross sections σ tot for the process H - + H - → H O +... for CM energies between 2.5 and 100 keV. Combining the present results with our previously measured cross sections for double-electron detachment (σ OO ) and triple-electron detachment (σ 0+ ), we obtain cross sections σ 0- for the single electron detachment process from the relation σ 0- = σ tot -σ 00 -σ 0+ . The experimental data of single- and double-electron detachment are well described by theoretical results based on the non-stationary tunnelling approach. Both cross sections are calculated for CM energies between 0.15 and 300 keV. A new two-electron simultaneous transition mechanism is introduced. The importance of this process for the theoretical assessment of the experimental results is discussed. (Author)

  5. Prenatal Phthalate Exposures and Anogenital Distance in Swedish Boys

    Science.gov (United States)

    Carlstedt, Fredrik; Jönsson, Bo AG.; Lindh, Christian H.; Jensen, Tina K.; Bodin, Anna; Jonsson, Carin; Janson, Staffan; Swan, Shanna H.

    2014-01-01

    Background: Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Because of reported health risks, diisononyl phthalate (DiNP) has been introduced as a replacement for di(2-ethylhexyl) phthalate (DEHP) in soft PVC. This raises concerns because animal data suggest that DiNP may have antiandrogenic properties similar to those of DEHP. The anogenital distance (AGD)—the distance from the anus to the genitals—has been used to assess reproductive toxicity. Objective: The objective of this study was to examine the associations between prenatal phthalate exposure and AGD in Swedish infants. Methods: AGD was measured in 196 boys at 21 months of age, and first-trimester urine was analyzed for 10 phthalate metabolites of DEP (diethyl phthalate), DBP (dibutyl phthalate), DEHP, BBzP (benzylbutyl phthalate), as well as DiNP and creatinine. Data on covariates were collected by questionnaires. Results: The most significant associations were found between the shorter of two AGD measures (anoscrotal distance; AGDas) and DiNP metabolites and strongest for oh-MMeOP [mono-(4-methyl-7-hydroxyloctyl) phthalate] and oxo-MMeOP [mono-(2-ethyl-5-oxohexyl) phthalate]. However, the AGDas reduction was small (4%) in relation to more than an interquartile range increase in DiNP exposure. Conclusions: These findings call into question the safety of substituting DiNP for DEHP in soft PVC, particularly because a shorter male AGD has been shown to relate to male genital birth defects in children and impaired reproductive function in adult males and the fact that human levels of DiNP are increasing globally. Citation: Bornehag CG, Carlstedt F, Jönsson BA, Lindh CH, Jensen TK, Bodin A, Jonsson C, Janson S, Swan SH. 2015. Prenatal phthalate exposures and anogenital distance in Swedish boys. Environ Health Perspect 123:101–107; http://dx.doi.org/10.1289/ehp.1408163 PMID:25353625

  6. Environmental phthalate monoesters activate pregnane X receptor-mediated transcription

    International Nuclear Information System (INIS)

    Hurst, Christopher H.; Waxman, David J.

    2004-01-01

    Phthalate esters, widely used as plasticizers in the manufacture of products made of polyvinyl chloride, induce reproductive and developmental toxicities in rodents. The mechanism that underlies these effects of phthalate exposure, including the potential role of members of the nuclear receptor superfamily, is not known. The present study investigates the effects of phthalates on the pregnane X receptor (PXR), which mediates the induction of enzymes involved in steroid metabolism and xenobiotic detoxification. The ability of phthalate monoesters to activate PXR-mediated transcription was assayed in a HepG2 cell reporter assay following transfection with mouse PXR (mPXR), human PXR (hPXR), or the hPXR allelic variants V140M, D163G, and A370T. Mono-2-ethylhexyl phthalate (MEHP) increased the transcriptional activity of both mPXR and hPXR (5- and 15-fold, respectively) with EC 50 values of 7-8 μM. mPXR and hPXR were also activated by monobenzyl phthalate (MBzP, up to 5- to 6-fold) but were unresponsive to monomethyl phthalate and mono-n-butyl phthalate (M(n)BP) at the highest concentrations tested (300 μM). hPXR-V140M and hPXR-A370T exhibited patterns of phthalate responses similar to the wild-type receptor. By contrast, hPXR-D163G was unresponsive to all phthalate monoesters tested. Further studies revealed that hPXR-D163G did respond to rifampicin, but required approximately 40-fold higher concentrations than wild-type receptor, suggesting that the ligand-binding domain D163G variant has impaired ligand-binding activity. The responsiveness of PXR to activation by phthalate monoesters demonstrated here suggests that these ubiquitous environmental chemicals may, in part, exhibit their endocrine disruptor activities by altering PXR-regulated steroid hormone metabolism with potential adverse health effects in exposed individuals

  7. The mechanism of hydrogen storage in single-walled carbon nanotube

    International Nuclear Information System (INIS)

    Yan Shiying; Yang Ziqin

    2012-01-01

    The C-H bong energy, 1.88 eV, and the bond length, 0.113 nm, are obtained from the calculation with Gaussian03 program. It is known that the H-H bong energy is 4.748 eV and the bond length is 0.074 nm. Obviously, H-H bond energy is greater than the C-H bond energy. So the hydrogen storage of carbon nanotube is due mainly to the physisorption and the chemisorption almost doesn't happen at moderate temperatures and pressures. In addition, LJ potential has been used to calculate the potential between a H 2 molecule and the carbon nanotube. The H 2 molecule is placed in three radial distributions: (a) above the center of a hexagon surrounded by 6 C atoms, (b) above the center of a C-C bond, (c) above the center of a C atom. The result shows that whether the H 2 molecule is adsorbed into and outside the nanotube or to the center and the end of the nanotube, there is the lowest potential when the H 2 molecule is above the center of a hexagon surrounded by 6 C atoms. When the H 2 molecule is absorbed to the center of nanotube, the equilibrium distances between it and the nanotube wall for H2 adsorbed into and outside the nanotube are 0.320 nm and 0. 309 nm, respectively. While in the case that it is adsorbed to the end of the nanotube, the two corresponding distances are 0.324 nm and 0.314 nm, respectively. (authors)

  8. Modeling of hydrogen production methods: Single particle model and kinetics assessment

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.S.; Bellan, J. [California Institute of Technology, Pasadena, CA (United States)

    1996-10-01

    The investigation carried out by the Jet Propulsion Laboratory (JPL) is devoted to the modeling of biomass pyrolysis reactors producing an oil vapor (tar) which is a precursor to hydrogen. This is an informal collaboration with NREL whereby JPL uses the experimentally-generated NREL data both as initial and boundary conditions for the calculations, and as a benchmark for model validation. The goal of this investigation is to find drivers of biomass fast-pyrolysis in the low temperature regime. The rationale is that experimental observations produce sparse discrete conditions for model validation, and that numerical simulations produced with a validated model are an economic way to find control parameters and an optimal operation regime, thereby circumventing costly changes in hardware and tests. During this first year of the investigation, a detailed mathematical model has been formulated for the temporal and spatial accurate modeling of solid-fluid reactions in biomass particles. These are porous particles for which volumetric reaction rate data is known a priori and both the porosity and the permeability of the particle are large enough to allow for continuous gas phase flow. The methodology has been applied to the pyrolysis of spherically symmetric biomass particles by considering previously published kinetics schemes for both cellulose and wood. The results show that models which neglect the thermal and species boundary layers exterior to the particle will generally over predict both the pyrolysis rates and experimentally obtainable tar yields. An evaluation of the simulation results through comparisons with experimental data indicates that while the cellulose kinetics is reasonably accurate, the wood pyrolysis kinetics is not accurate; particularly at high reactor temperatures. Current effort in collaboration with NREL is aimed at finding accurate wood kinetics.

  9. Impact of ecological doses of the most widespread phthalate on a terrestrial species, the ant Lasius niger.

    Science.gov (United States)

    Cuvillier-Hot, Virginie; Salin, Karine; Devers, Séverine; Tasiemski, Aurélie; Schaffner, Pauline; Boulay, Raphaël; Billiard, Sylvain; Lenoir, Alain

    2014-05-01

    Phthalates are synthetic contaminants released into the environment notably by plastic waste. Semi-volatile, they adsorb to atmospheric particles and get distributed in all ecosystems. Effects of this major anthropogenic pollution in economical species in aquatic habitats have attracted large interest. On the contrary, very few studies have focused on wild terrestrial species. Yet, these lipophilic molecules are easily trapped by insect cuticle; ants and other insects have been shown to permanently bear among their cuticular components a non-negligible proportion of phthalates, meaning that they suffer from chronic exposure to these pollutants. Oral route could also be an additional way of contamination, as phthalates tend to stick to any organic particle. We show here via a food choice experiment that Lasius niger workers can detect, and avoid feeding on, food contaminated with DEHP (DiEthyl Hexyl Phthalate), the most widespread phthalate found in nature. This suggests that the main source of contamination for ants is atmosphere and that doses measured on the cuticle correspond to the chronic exposure levels for these animals. Such an ecologically relevant dose of DEHP was used to contaminate ants in lab and to investigate their physiological impact. Over a chronic exposure (1 dose per week for 5 weeks), the egg-laying rate of queens was significantly reduced lending credence to endocrine disruptive properties of such a pollutant, as also described for aquatic invertebrates. On the contrary, short term exposure (24h) to a single dose of DEHP does not induce oxidative stress in ant workers as expected, but leads to activation of the immune system. Because of their very large distribution, their presence in virtually all terrestrial ecosystems and their representation at all trophic levels, ants could be useful indicators of contamination by phthalates, especially via monitoring the level of activation of their immune state. Copyright © 2014 Elsevier Inc. All

  10. Phthalates and heavy metals as endocrine disruptors in food: A study on pre-packed coffee products.

    Science.gov (United States)

    De Toni, Luca; Tisato, Francesco; Seraglia, Roberta; Roverso, Marco; Gandin, Valentina; Marzano, Cristina; Padrini, Roberto; Foresta, Carlo

    2017-01-01

    Phthalate plasticizers and heavy metals are widely recognized to be pollutants that interfere with key developmental processes such as masculinization. We investigated the release of phthalates and heavy metals in coffee brewed from coffee packed in single-serve coffee containers made from different types of materials: metal, biodegradable and plastics. We detected with GC-MS small amounts phthalates, below the tolerated daily risks levels, in all the coffees prepared from the different types of capsules. Specifically, Di (2-ethyl-hexyl)-phthalate and DiBP: Diisobuthyl-pthalate were ubiquitously present despite the high variability among the samples (respective range 0.16-1.87 μg/mL and 0.01-0.36 μg/mL). Whereas, diethyl-phthalate (range 0.20-0.26 μg/mL) and di- n -buthyl-phthalate (range 0.02-0.14 μg/mL) were detected respectively in one and three out of the four types of capsule tested. In contrast, we detected by atomic mass spectrometry on mineralized samples heavy metals lead (Pb) and nickel (Ni), in all coffee tested. PB levels (respective range 0.32-211.57 μg/dose) accounted for 42-79%, whereas Ni levels (respective range 166.25-1950.26 μg/dose) accounted for >100% of the tolerable daily intake. These results add to the already present concerns related to the multiple pathways of human exposure and the ubiquitous presence of these pollutants in consumer products and their long-term effect on human health.

  11. Some aspects of hydrogen plasma treatment of anti-modulation doped near surface GaAs/AlGaAs single quantum well structures

    International Nuclear Information System (INIS)

    Bumai, Yu.A.; Gobsch, G.; Goldhahn, R.; Stein, N.; Golombek, A.; Nakov, V.; Cheng, T.S.

    1999-01-01

    The MBE grown anti-modulation doped GaAs/AlGaAs structures with near surface single quantum wells were exposed to a DC hydrogen plasma (∼400 eV) and investigated using PL, PLE and PR spectroscopy at 5 K. Strong acceptor related free to bound transition (FB) dominates for quantum well related PL but excitonic features are still observed in PLE spectra. After hydrogen plasma treatment the PL intensity of FB transition from quantum well was strongly increased for above AlGaAs band gap excitation and was unchanged for below AlGaAs one. These results are consistent with atomic hydrogen passivation of deep defects in AlGaAs barriers. At the same time radiative excitonic recombination was quenched by hydrogenation. PLE and PR spectra indicate on a strong increase of electric field in subsurface region of the structure after hydrogenation. The increase of electric field in anti-modulation doped structure after hydrogen plasma treatment is supposed to be due to passivation by atomic hydrogen of surface states that leads to unpinning of Fermi level from mid gap to carbon acceptor level position in GaAs cap layer. It causes the further band bending and surface electric field increase that strongly suppress excitonic recombination in near surface quantum wells

  12. Synthesis, structure and magnetic properties of cobalt(II) and copper(II) coordination polymers assembled by phthalate and 4-methylimidazole

    International Nuclear Information System (INIS)

    Baca, S.G.; Malinovskii, S.T.; Franz, Patrick; Ambrus, Christina; Stoeckli-Evans, Helen; Gerbeleu, Nicolae; Decurtins, Silvio

    2004-01-01

    New coordination polymers [M(Pht)(4-MeIm) 2 (H 2 O)] n (M=Co (1), Cu (2); Pht 2- =dianion of o-phthalic acid; 4-MeIm=4-methylimidazole) have been synthesized and characterized by IR spectroscopy, X-ray crystallography, thermogravimetric analysis and magnetic measurements. The crystal structures of 1 and 2 are isostructural and consist of [M(4-MeIm) 2 (H 2 O)] building units linked in infinite 1D helical chains by 1,6-bridging phthalate ions which also act as chelating ligands through two O atoms from one carboxylate group in the case of 1. In complex 1, each Co(II) atom adopts a distorted octahedral N 2 O 4 geometry being coordinated by two N atoms from two 4-MeIm, three O atoms of two phthalate residues and one O atom of a water molecule, whereas the square-pyramidal N 2 O 3 coordination of the Cu(II) atom in 2 includes two N atoms of N-containing ligands, two O atoms of two carboxylate groups from different Pht, and a water molecule. An additional strong O-H↑··O hydrogen bond between a carboxylate group of the phthalate ligand and a coordinated water molecule join the 1D helical chains to form a 2D network in both compounds. The thermal dependences of the magnetic susceptibilities of the polymeric helical Co(II) chain compound 1 were simulated within the temperature range 20-300 K as a single ion case, whereas for the Cu(II) compound 2, the simulations between 25 and 300 K, were made for a linear chain using the Bonner-Fisher approximation. Modelling the experimental data of compound 1 with MAGPACK resulted in: g=2.6, vertical bar D vertical bar=62 cm -1 . Calculations using the Bonner-Fisher approximation gave the following result for compound 2: g=2.18, J=-0.4 cm -1

  13. Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans

    DEFF Research Database (Denmark)

    Janjua, Nadeem Rezaq; Frederiksen, Hanne; Skakkebaek, Niels E

    2008-01-01

    Diethyl phthalate (DEP), dibutyl phthalate (DBP) and butyl paraben (BP) are man-made chemicals used in personal care products, such as lotions and creams. Exposure to these chemicals causes a variety of adverse reproductive outcomes in animal studies. Humans can be exposed to these chemicals...... through dermal absorption, but there are no published data on absorption, metabolism, and excretion after dermal application. This study investigates urinary concentrations of BP and metabolites of DEP and DBP after topical application. In a 2-week single-blinded study, 26 healthy Caucasian male subjects.......1%, respectively. Absorption of DEP, DBP and BP through skin could potentially contribute to adverse health effects. The three chemicals are systemically absorbed, metabolized and excreted in urine following application on the skin in a cream preparation. More DEP than DBP was absorbed, presumably because...

  14. Fragmentation of high-energy ionic hydrogen clusters by single collision with helium

    International Nuclear Information System (INIS)

    Ouaskit, S.; Farizon, B.; Farizon, M.; Gaillard, M.J.; Chevarier, A.; Chevarier, N.; Gerlic, E.; Stern, M.

    1994-09-01

    Fragmentation of mass-selected 60-keV/amu-H n + induced by single collision with helium has been studied for various cluster sizes n (9, 13,21, 25, and 31). The absolute cross sections of the charged fragments H p + are measured from p equal to n-2. The deduced mass distributions are strongly different from those obtained at lower collision energy (where molecular evaporation is mainly involved) due to a strong production of ionic fragments with a size of p/n -τ , where A is the normalized fragment mass (p/n) and τ an exponent close to 2.6. (authors)

  15. Influence of copper single crystal structures on the reflection of low energy hydrogen and helium ions

    International Nuclear Information System (INIS)

    Feijen, H.H.W.

    1975-01-01

    A theoretical basis for the 'wedge-focussing' phenomenon is outlined. Investigations have been made to check up to what extent proton reflection can be simulated by using H 2 + or H 3 + as incident ions and analysing the reflected protons. The results of an experimental study of the influence of surface semi-channels on the reflection of low energy ( + , H 2 + and He + ions from copper single crystals with attention to the wedge-focussing effect are presented (G.T.H.)

  16. Growth and characterization of hexaaquacobalt(II) dipotassium tetrahydrogen tetra-o-phthalate tetrahydrate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Muthu, K. [Department of Chemistry, Annamalai University, Annamalainagar 608 002 (India); Bhagavannarayana, G. [National Physical Laboratory (CSIR), New Delhi 110 012 (India); Mahadevan, C.K. [Physics Research Centre, S.T. Hindu College, Nagercoil 629002 (India); Meenakshisundaram, S.P., E-mail: aumats2009@gmail.com [Department of Chemistry, Annamalai University, Annamalainagar 608 002 (India)

    2013-05-15

    Single crystals of hexaaquacobalt(II) dipotassium tetrahydrogen tetra-o-phthalate tetrahydrate K{sub 2}[Co(H{sub 2}O){sub 6}](C{sub 8}H{sub 5}O{sub 4}){sub 4}·4H{sub 2}O (PCHP), a semiorganic light-rose colored crystal of size ∼38 × 16 × 4 mm{sup 3} have been grown by slow evaporation solution growth technique. The lattice parameters of the as-grown crystals were obtained by single crystal X-ray diffraction analysis. The functional groups of the phthalate complex were confirmed by Fourier transform infrared spectroscopy analysis. The UV–Vis optical absorption spectrum of PCHP shows the lower optical cut-off at ∼300 nm and the crystal was transparent in the visible region. The structural perfection of the grown crystal has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curves (DC). The DC contains multi-peaks showing the structural grain boundaries. The dielectric, thermal and mechanical behaviors of the specimen were also studied. - Highlights: ► Bulk growth of large size phthalate complex crystals. ► Crystalline perfection of the grown crystal has been determined. ► HRXRD curves compared with pure material and the reasons are analyzed.

  17. Synthesis, crystal growth, optical, thermal, and mechanical properties of a nonlinear optical single crystal: ammonium sulfate hydrogen sulphamate (ASHS)

    Science.gov (United States)

    Sudhakar, K.; Nandhini, S.; Muniyappan, S.; Arumanayagam, T.; Vivek, P.; Murugakoothan, P.

    2018-04-01

    Ammonium sulfate hydrogen sulphamate (ASHS), an inorganic nonlinear optical crystal, was grown from the aqueous solution by slow evaporation solution growth technique. The single-crystal XRD confirms that the grown single crystal belongs to the orthorhombic system with the space group of Pna21. Powder XRD confirms the crystalline nature and the diffraction planes were indexed. Crystalline perfection of grown crystal was analysed by high-resolution X-ray diffraction rocking curve technique. UV-Vis-NIR studies revealed that ASHS crystal has optical transparency 65% and lower cut-off wavelength at 218 nm. The violet light emission of the crystal was identified by photoluminescence studies. The particle size-dependent second-harmonic generation efficiency for ASHS crystal was evaluated by Kurtz-Perry powder technique using Nd:YAG laser which established the existence of phase matching. Surface laser damage threshold value was evaluated using Nd:YAG laser. Optical homogeneity of the crystal was evaluated using modified channel spectrum method through birefringence study. Thermal analysis reveals that ASHS crystal is stable up to 213 °C. The mechanical behaviour of the ASHS crystal was analysed using Vickers microhardness study.

  18. Evaluation of the Levels of phthalate Ester Plasticizers in Surface ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Gas chromatography (GC) coupled with mass ... Key words: phthalates, acid esters, plasticizers, Ethiope River, surface water, pollution ... waste and emissions arising from burning of refuse ... deepest inland waterways in Africa, is known for its ..... carbon nitride nanocomposites for the solid-phase extraction of phthalate ...

  19. Determination of Phthalate Esters in the Aquatic Environment ...

    African Journals Online (AJOL)

    The use of solid phase extraction and capillary GLC provides the basis for selective determination of phthalate ester plasticizers in rivers and marine water samples. Of the several solvent ratios (methanol in dichloromethane) that were tried for selective elution of phthalate esters from the C18 solid phase glass catridge, the ...

  20. Degradation and impact of phthalate plasticizers on soil microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, C.D.; Thompson, I.P.; Burns, R.G.

    2000-05-01

    To assess the impact of phthalates on soil microorganisms and to supplement the environmental risk assessment for these xenobiotics, soil was treated with diethyl phthalate (DEP) or di (2-ethyl hexyl) phthalate (DEHP) at 0.1 to 100 mg/g. Bioavailability and membrane disruption were proposed as the characteristics responsible for the observed fate and toxicity of both compounds. Diethyl phthalate was biodegraded rapidly in soil with a half-life of 0.75 d at 20 C, and was not expected to persist in the environment. The DEHP, although biodegradable in aqueous solution, was recalcitrant in soil, because of poor bioavailability and was predicted to account for the majority of phthalate contamination in the environment. Addition of DEP or DEHP to soil at a concentration similar to that detected in nonindustrial environments had no impact on the structural diversity or functional diversity (BIOLOG) of the microbial community. At concentrations representative of a phthalate spill, DEP reduced numbers of both total culturable bacteria and pseudomonads within 1 d. This was due to disruption of membrane fluidity by the lipophilic phthalate, a mechanism not previously attributed to phthalates. However, DEHP had no effect on the microbial community or membrane fluidity, even at 100 mg/g, and was predicted to have no impact on microbial communities in the environment.

  1. The influence of resource strategy on childhood phthalate exposure

    DEFF Research Database (Denmark)

    Lee, Jihyun; Pedersen, Anders Branth; Thomsen, Marianne

    2014-01-01

    and paper at European level, including the flow of phthalates, i.e. Di(2-ethylhexyl) phthalate (DEHP), Di-n-butyl phthalate (DBP), and Benzyl-butyl phthalate (BBP), has been performed. The result for the year 2012 shows that 26% of plastic wastes and 60% of paper consumed in Europe were recycled....... This corresponds to the recycling of 6.3% of DEHP, 20.3% of DBP, and 5.1% of BBP in the percentage of total manufactured amount of these phthalates. To examine the potential influence of the phthalate exposure through recycling, a case study assessing the childhood exposures to phthalates from foods packed.......767 µg/kg bw/day for Denmark and Korea, respectively. Still, of the total childhood phthalate exposure, 58.5% of DBP and 77.5% of BBP exposure in Denmark and 31.6% of DBP and 65.2% of BBP in Korea remains to be identified. Finally, a conceptual framework is proposed for a circular economy based...

  2. Postnatal effects of dipentyl phthalate on male reproductive development

    Science.gov (United States)

    We conducted several in utero, ex vivo and in vitro studies to characterize the relative potencies of a series of phthalates on fetal rat testis testosterone production and gene expression. Dipentyl phthalate (DPeP) was the most potent of the active chemicals in its effect on fet...

  3. Local stabilization of single-walled carbon nanotubes on Si(100)-2 x 1:H via nanoscale hydrogen desorption with an ultrahigh vacuum scanning tunnelling microscope

    International Nuclear Information System (INIS)

    Albrecht, Peter M; Lyding, Joseph W

    2007-01-01

    An ultrahigh vacuum scanning tunnelling microscope (UHV-STM) was used to modify the interface between isolated ∼10 A-diameter single-walled carbon nanotubes (SWNTs) and the hydrogen-passivated Si(100) surface. Room-temperature UHV-STM desorption of hydrogen at the SWNT/H-Si(100) interface resulted in the local mechanical stabilization of tubes originally perturbed by the rastered STM tip under nominal imaging conditions. For the section of the SWNT contacted by depassivated Si, a topographic depression of 1.5 A (1 A) was measured in the case of parallel (nearly perpendicular) alignment between the tube axis and the Si dimer rows, in agreement with existing first-principles calculations. The compatibility of hydrogen-resist UHV-STM nanolithography with SWNTs adsorbed on H-Si(100) would enable the atomically precise placement of single molecules in proximity to the tube for the bottom-up fabrication of molecular electronic devices

  4. Prenatal phthalate exposure and reduced masculine play in boys.

    Science.gov (United States)

    Swan, S H; Liu, F; Hines, M; Kruse, R L; Wang, C; Redmon, J B; Sparks, A; Weiss, B

    2010-04-01

    Foetal exposure to antiandrogens alters androgen-sensitive development in male rodents, resulting in less male-typical behaviour. Foetal phthalate exposure is also associated with male reproductive development in humans, but neurodevelopmental outcomes have seldom been examined in relation to phthalate exposure. To assess play behaviour in relation to phthalate metabolite concentration in prenatal urine samples, we recontacted participants in the Study for Future Families whose phthalate metabolites had been measured in mid-pregnancy urine samples. Mothers completed a questionnaire including the Pre-School Activities Inventory, a validated instrument used to assess sexually dimorphic play behaviour. We examined play behaviour scores (masculine, feminine and composite) in relationship to (log(10)) phthalate metabolite concentrations in mother's urine separately for boys (N = 74) and girls (N = 71). Covariates (child's age, mother's age and education and parental attitude towards atypical play choices) were controlled using multivariate regression models. Concentrations of dibutyl phthalate metabolites, mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) and their sum, were associated with a decreased (less masculine) composite score in boys (regression coefficients -4.53,-3.61 and -4.20, p = 0.01, 0.07 and 0.04 for MnBP, MiBP and their sum respectively). Concentrations of two urinary metabolites of di(2-ethylhexyl) phthalate (DEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and the sum of these DEHP metabolites plus mono(2-ethylhexyl) phthalate were associated with a decreased masculine score (regression coefficients -3.29,-2.94 and -3.18, p = 0.02, 0.04 and 0.04) for MEHHP, MEOHP and the sum respectively. No strong associations were seen between behaviour and urinary concentrations of any other phthalate metabolites in boys, or between girls' scores and any metabolites. These data, although based on

  5. Phthalate exposure and semen quality in fertile US men.

    Science.gov (United States)

    Thurston, S W; Mendiola, J; Bellamy, A R; Levine, H; Wang, C; Sparks, A; Redmon, J B; Drobnis, E Z; Swan, S H

    2016-07-01

    Several experimental and observational studies have demonstrated the antiandrogenicity of several phthalates. However, there is limited evidence of an association between phthalate exposure in adult life and semen quality. The aim of this study was to examine phthalate exposure during adulthood in relation to semen quality in fertile US men. This multi-center cross-sectional study included 420 partners of pregnant women who attended a prenatal clinic in one of five US cities during 1999-2001. Nine phthalate metabolites [mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono (2-ethyl-5-carboxypentyl) phthalate (MECPP)], as well as mono-n-butyl phthalate (MBP) and mono-isobutyl phthalate (MiBP), mono (three carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP), and monoethyl phthalate (MEP)] were measured in urine collected at the same time as the semen sample. We regressed natural log-transformed (ln) sperm concentration, ln(total sperm count), ln(total motile sperm count), percent motile spermatozoa, and percent spermatozoa with normal morphology on each of the nine natural log-transformed metabolite concentrations and on the molar-weighted sum of DEHP metabolites in separate models. We fit unadjusted models and models that adjusted for confounders determined a priori. In unadjusted models, ln(MiBP) was significantly and positively associated with motility and ln(MBzP) significantly negatively associated with ln(total sperm count). In adjusted linear models, urinary metabolite concentrations of DEHP, DBP, DEP, and DOP were not associated with any semen parameter. We found an inverse association between ln(MBzP) concentrations and sperm motility (β = -1.47, 95% CI: -2.61, -0.33), adjusted for ln(creatinine concentration), geographic location, age, race, smoking status, stress, recent fever, time from sample collection and time to complete analysis. Several sensitivity

  6. Prohibition of Children’s Toys and Child Care Articles Containing Specified Phthalates. Final rule.

    Science.gov (United States)

    2017-10-27

    The United States Consumer Product Safety Commission (Commission or CPSC) issues this final rule prohibiting children's toys and child care articles that contain concentrations of more than 0.1 percent of diisononyl phthalate (DINP), diisobutyl phthalate (DIBP), di-n-pentyl phthalate (DPENP), di-n-hexyl phthalate (DHEXP), and dicyclohexyl phthalate (DCHP). Section 108 of the Consumer Product Safety Improvement Act of 2008 (CPSIA) established permanent and interim prohibitions on the sale of certain consumer products containing specific phthalates. That provision also directed the CPSC to convene a Chronic Hazard Advisory Panel (CHAP) to study the effects on children's health of all phthalates and phthalate alternatives as used in children's toys and child care articles and to provide recommendations to the Commission regarding whether any phthalates or phthalate alternatives, other than those already permanently prohibited, should be prohibited. The CPSIA requires the Commission to promulgate a final rule after receiving the final CHAP report. This rule fulfills that requirement.

  7. Fetal Phthalate Screen: Assessment of Several Phthalate Esters on Fetal Rodent Testosterone Production and Gene Expression Following In Utero Exposure

    Science.gov (United States)

    Phthalate esters(PE) are a large family of compounds used in a wide array of common products from medical tubing to pharmaceuticals to cables, and wall/floor coverings. Laboratory studies have demonstrated that in utero treatment with PE such as di-ethyl hexyl phthalate (DEHP) du...

  8. 76 FR 75537 - Notice of Teleconference of the Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2011-12-02

    ... the teleconference. Interested parties should contact the CPSC project manager, Michael Babich, by... FURTHER INFORMATION CONTACT: To request access to the teleconference, contact the project manager by email... other phthalates; Examine the likely levels of children's, pregnant women's, and others' exposure to...

  9. 76 FR 57024 - Notice of Teleconference of the Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2011-09-15

    ... otherwise participate in the teleconference. Interested parties should contact the CPSC project manager... manager by e-mail at [email protected] , no later than Friday, September 16, 2011. For all other questions... other phthalates; Examine the likely levels of children's, pregnant women's, and others' exposure to...

  10. 77 FR 34028 - Notice of Teleconference of the Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2012-06-08

    ... participate in the teleconference. Interested parties should contact the CPSC project manager, Michael Babich... combination with other phthalates; Examine the likely levels of children's, pregnant women's, and others... women, or other susceptible individuals and their offspring, considering the best available science, and...

  11. 77 FR 19005 - Notice of Teleconference of the Chronic Hazard Advisory Panel on Phthalates and Phthalate...

    Science.gov (United States)

    2012-03-29

    ... participate in the teleconference. Interested parties should contact the CPSC project manager, Michael Babich... combination with other phthalates; Examine the likely levels of children's, pregnant women's, and others... women, or other susceptible individuals and their offspring, considering the best available science, and...

  12. 75 FR 73048 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate Substitutes

    Science.gov (United States)

    2010-11-29

    ... Consider possible similar health effects of phthalate alternatives used in children's toys and child care... CPSIA requires the Commission to convene a CHAP ``to study the effects on children's health of all... children and: Examine all of the potential health effects (including endocrine disrupting effects) of the...

  13. Decrease in anogenital distance among male infants with prenatal phthalate exposure

    DEFF Research Database (Denmark)

    Swan, Shanna H; Main, Katharina M; Liu, Fan

    2005-01-01

    a summary phthalate score to quantify joint exposure to these four phthalate metabolites. The age-adjusted AGI decreased significantly with increasing phthalate score (p-value for slope = 0.009). The associations between male genital development and phthalate exposure seen here are consistent...... States, based on a nationwide sample. These data support the hypothesis that prenatal phthalate exposure at environmental levels can adversely affect male reproductive development in humans....

  14. Characterization of the Phthalate Permease OphD from Burkholderia cepacia ATCC 17616†

    OpenAIRE

    Chang, Hung-Kuang; Zylstra, Gerben J.

    1999-01-01

    The ophD gene, encoding a permease for phthalate transport, was cloned from Burkholderia cepacia ATCC 17616. Expression of the gene in Escherichia coli results in the ability to transport phthalate rapidly into the cell. Uptake inhibition experiments show that 4-hydroxyphthalate, 4-chlorophthalate, 4-methylphthalate, and cinchomeronate compete for the phthalate permease. An ophD knockout mutant of 17616 grows slightly more slowly on phthalate but is still able to take up phthalate at rates eq...

  15. Urinary excretion of phthalate metabolites in 129 healthy Danish children and adolescents: Estimation of daily phthalate intake

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Aksglaede, Lise; Sørensen, Kaspar

    2011-01-01

    Background Phthalates are a group of chemicals with widespread use in the industrial production of numerous consumer products. They are suspected to be involved in male reproductive health problems and have also been associated with several other health problems in children including obesity...... and asthma. Objectives To study the urinary excretion of phthalate metabolites in Danish children recruited from the general population, and to estimate the daily intake of phthalates in this segment of the population. Method One 24 h urine sample and to consecutive first morning urine samples were collected...... from 129 healthy Danish children and adolescents (range 6–21 yrs). The concentrations of 11 phthalate metabolites of 5 different phthalate diesters were analyzed by liquid chromatography–tandem mass spectrometry. Results The analyzed metabolites were detectable in almost all 24 h urine samples...

  16. Hydrogen gas production is associated with reduced interleukin-1β mRNA in peripheral blood after a single dose of acarbose in Japanese type 2 diabetic patients.

    Science.gov (United States)

    Tamasawa, Atsuko; Mochizuki, Kazuki; Hariya, Natsuyo; Saito, Miyoko; Ishida, Hidenori; Doguchi, Satako; Yanagiya, Syoko; Osonoi, Takeshi

    2015-09-05

    Acarbose, an α-glucosidase inhibitor, leads to the production of hydrogen gas, which reduces oxidative stress. In this study, we examined the effects of a single dose of acarbose immediately before a test meal on postprandial hydrogen gas in breath and peripheral blood interleukin (IL)-1β mRNA expression in Japanese type 2 diabetic patients. Sixteen Japanese patients (14 men, 2 women) participated in this study. The mean±standard deviation age, hemoglobin A1c and body mass index were 52.1±15.4 years, 10.2±2.0%, and 27.7±8.0kg/m(2), respectively. The patients were admitted into our hospital for 2 days and underwent test meals at breakfast without (day 1) or with acarbose (day 2). We performed continuous glucose monitoring and measured hydrogen gas levels in breath, and peripheral blood IL-1β mRNA levels before (0min) and after the test meal (hydrogen gas: 60, 120, 180, and 300min; IL-1β: 180min). The induction of hydrogen gas production and the reduction in peripheral blood IL-1β mRNA after the test meal were not significant between days 1 (without acarbose) and 2 (with acarbose). However, the changes in total hydrogen gas production from day 1 to day 2 were closely and inversely associated with the changes in peripheral blood IL-1β mRNA levels. Our results suggest that an increase in hydrogen gas production is inversely associated with a reduction of the peripheral blood IL-1β mRNA level after a single dose of acarbose in Japanese type 2 diabetic patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Chemical behavior of phthalates under abiotic conditions in landfills.

    Science.gov (United States)

    Huang, Jingyu; Nkrumah, Philip N; Li, Yi; Appiah-Sefah, Gloria

    2013-01-01

    The phthalates comprise a family of phthalic acid esters that are used primarily as plasticizers in polymeric materials to impart flexibility during the manufacturing process and to the end product. It is estimated that the annual worldwide production of phthalate esters exceeds five million tons. Plasticizers are one of the most prominent classes of chemicals, but unfortunately, they possess endocrine-disrupting chemical properties. As endocrine-disrupting chemicals, plasticizers have produced adverse developmental and reproductive effects in mammalian animal models.Phthalates are easily transported into the environment during manufacture, disposal,and leaching from plastic materials, because they are not covalently bound to the plastics of which they are a component. Because of their fugitive nature and widespread use, the phthalates are commonly detected in air, water, sediment/soil, and biota, including human tissue. Large amounts of phthalic acid esters are often leached from the plastics that are dumped at municipal landfills.Phthalate esters undergo chemical changes when released into the environment.The primary processes by which they are transformed include hydrolysis, photolysis,and biodegradation. It is noteworthy that all of these degradation processes are greatly influenced by the local physical and chemical conditions. Hence, in the present review, we have sought to ascertain from the literature how the phthalate esters undergo transformation when they are released into lower landfill layers.Within the upper landfill layers, biodegradation prevails as the major degradation mechanism by which the phthalates are dissipated. Generally, biodegradation pathways for the phthalates consist of primary biodegradation from phthalate diesters to phthalate monoesters, then to phthalic acid, and ultimately biodegradation of phthalic acid to form C02 and/or CH4• We have noted that the phthalate esters are also degraded through abiotic means,which proceeds via

  18. Human Biological Monitoring of Diisononyl Phthalate and Diisodecyl Phthalate: A Review

    Directory of Open Access Journals (Sweden)

    Gurusankar Saravanabhavan

    2012-01-01

    Full Text Available High molecular-weight phthalates, such as diisononyl phthalate (DINP, and diisodecyl phthalate (DIDP, are widely used as plasticizers in the manufacturing of polymers and consumer products. Human biological monitoring studies have employed the metabolites of DINP and DIDP as biomarkers to assess human exposure. In this review, we summarize and analyze publicly available scientific data on chemistry, metabolism, and excretion kinetics, of DINP and DIDP, to identify specific and sensitive metabolites. Human biological monitoring data on DINP and DIDP are scrutinised to assess the suitability of these metabolites as biomarkers of exposure. Results from studies carried out in animals and humans indicate that phthalates are metabolised rapidly and do not bioaccmulate. During Phase-I metabolism, ester hydrolysis of DINP and DIDP leads to the formation of hydrolytic monoesters. These primary metabolites undergo further oxidation reactions to produce secondary metabolites. Hence, the levels of secondary metabolites of DINP and DIDP in urine are found to be always higher than the primary metabolites. Results from human biological monitoring studies have shown that the secondary metabolites of DINP and DIDP in urine were detected in almost all tested samples, while the primary metabolites were detected in only about 10% of the samples. This indicates that the secondary metabolites are very sensitive biomarkers of DINP/DIDP exposure while primary metabolites are not. The NHANES data indicate that the median concentrations of MCIOP and MCINP (secondary metabolites of DINP and DIDP, resp. at a population level are about 5.1 μg/L and 2.7 μg/L, respectively. Moreover, the available biological monitoring data suggest that infants/children are exposed to higher levels of phthalates than adults.

  19. Human Biological Monitoring of Diisononyl Phthalate and Diisodecyl Phthalate: A Review

    International Nuclear Information System (INIS)

    Saravanabhavan, G.; Murray, J.

    2012-01-01

    High molecular-weight phthalates, such as diisononyl phthalate (Din), and diisodecyl phthalate (DIDP), are widely used as plasticizers in the manufacturing of polymers and consumer products. Human biological monitoring studies have employed the metabolites of DINP and DIDP as bio markers to assess human exposure. In this review, we summarize and analyze publicly available scientific data on chemistry, metabolism, and excretion kinetics, of DINP and DIDP, to identify specific and sensitive metabolites. Human biological monitoring data on DINP and DIDP are scrutinised to assess the suitability of these metabolites as bio markers of exposure. Results from studies carried out in animals and humans indicate that phthalates are metabolised rapidly and do not bio accumulate. During Phase-I metabolism, ester hydrolysis of DINP and DIDP leads to the formation of hydrolytic monoesters. These primary metabolites undergo further oxidation reactions to produce secondary metabolites. Hence, the levels of secondary metabolites of DINP and DIDP in urine are found to be always higher than the primary metabolites. Results from human biological monitoring studies have shown that the secondary metabolites of DINP and DIDP in urine were detected in almost all tested samples, while the primary metabolites were detected in only about 10% of the samples. This indicates that the secondary metabolites are very sensitive bio markers of DINP/DIDP exposure while primary metabolites are not. The NHANES data indicate that the median concentrations of MCIOP and MCINP (secondary metabolites of DINP and DIDP, resp.) at a population level are about 5.1 μg/L and 2.7 μg/L, respectively. Moreover, the available biological monitoring data suggest that infants/children are exposed to higher levels of phthalates than adults.

  20. DETERMINATION OF DIBUTYL PHTHALATE (DBP, BENZYL BUTYL PHTHALATE (BBP AND BIS (2-ETHYLHEXYL PHTHALATE (DEHP IN SOFT PLASTIC TOYS AND THE FIRST SURVEY OF THE BULGARIAN MARKET

    Directory of Open Access Journals (Sweden)

    Valentina CHRISTOVA-BAGDASSARIAN

    2017-12-01

    Full Text Available Phthalates are a large group of compounds with similar chemical structure widely used as plasticizers for plastics. They can easily be released from the polymer during usage and in this way enter the human body. Their adverse effect on health is known as "phthalate syndrome" and can impact children and adults alike. For children in particular, there is an additional potential risk of exposure to phthalates via toys intended for oral use. The Regulation (EC No 1907/2006 (REACH prohibits the use of bis (2-ethylhexyl phthalate (DEHP, di butyl phthalate (DBP and benzyl butyl phthalate (BBP as a substance or constituent of preparations at concentrations higher than 0.1 % in the plasticized material meant to toys and childcare items. The aim of this article is to quantify the content of DEHP, DBP and BBP in soft toys intended for children up to 3 years of age, including toys designed to be placed in the mouth. A method consisting of an extraction procedure of phthalates from polymers, purification of the extract, followed by GC/MS identification and quantification was validated. Three different techniques for phthalates’ extraction (Soxhlet, ultrasonic and vibrator were compared and the most effective one was chosen.This method was applied to the analysis of DEHP, DBP and BBP in soft toys from the Bulgarian market to establish their compliance with REACH requirements. All the tested toys contained at least one phthalate. Exceedence of the permitted content for DEHP, DBP and BBP (as sume, mainly due to the high levels of DEHP, was observed in several toys from retail.

  1. Rapid and molecular selective electrochemical sensing of phthalates in aqueous solution

    KAUST Repository

    Zia, Asif I.

    2015-05-01

    Reported research work presents real time non-invasive detection of phthalates in spiked aqueous samples by employing electrochemical impedance spectroscopy (EIS) technique incorporating a novel interdigital capacitive sensor with multiple sensing thin film gold micro-electrodes fabricated on native silicon dioxide layer grown on semiconducting single crystal silicon wafer. The sensing surface was functionalized by a self-assembled monolayer of 3-aminopropyltrietoxysilane (APTES) with embedded molecular imprinted polymer (MIP) to introduce selectivity for the di(2-ethylhexyl) phthalate (DEHP) molecule. Various concentrations (1-100. ppm) of DEHP in deionized MilliQ water were tested using the functionalized sensing surface to capture the analyte. Frequency response analyzer (FRA) algorithm was used to obtain impedance spectra so as to determine sample conductance and capacitance for evaluation of phthalate concentration in the sample solution. Spectrum analysis algorithm interpreted the experimentally obtained impedance spectra by applying complex nonlinear least square (CNLS) curve fitting in order to obtain electrochemical equivalent circuit and corresponding circuit parameters describing the kinetics of the electrochemical cell. Principal component analysis was applied to deduce the effects of surface immobilized molecular imprinted polymer layer on the evaluated circuit parameters and its electrical response. The results obtained by the testing system were validated using commercially available high performance liquid chromatography diode array detector system.

  2. Rational Design of Single Molybdenum Atoms Anchored on N-Doped Carbon for Effective Hydrogen Evolution Reaction.

    Science.gov (United States)

    Chen, Wenxing; Pei, Jiajing; He, Chun-Ting; Wan, Jiawei; Ren, Hanlin; Zhu, Youqi; Wang, Yu; Dong, Juncai; Tian, Shubo; Cheong, Weng-Chon; Lu, Siqi; Zheng, Lirong; Zheng, Xusheng; Yan, Wensheng; Zhuang, Zhongbin; Chen, Chen; Peng, Qing; Wang, Dingsheng; Li, Yadong

    2017-12-11

    The highly efficient electrochemical hydrogen evolution reaction (HER) provides a promising pathway to resolve energy and environment problems. An electrocatalyst was designed with single Mo atoms (Mo-SAs) supported on N-doped carbon having outstanding HER performance. The structure of the catalyst was probed by aberration-corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption fine structure (XAFS) spectroscopy, indicating the formation of Mo-SAs anchored with one nitrogen atom and two carbon atoms (Mo 1 N 1 C 2 ). Importantly, the Mo 1 N 1 C 2 catalyst displayed much more excellent activity compared with Mo 2 C and MoN, and better stability than commercial Pt/C. Density functional theory (DFT) calculation revealed that the unique structure of Mo 1 N 1 C 2 moiety played a crucial effect to improve the HER performance. This work opens up new opportunities for the preparation and application of highly active and stable Mo-based HER catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Phthalate metabolites in urine samples from Danish children and correlations with phthalates in dust samples from their homes and daycare centers

    DEFF Research Database (Denmark)

    Langer, S.; Bekö, Gabriel; Weschler, Charles J.

    2013-01-01

    Around the world humans use products that contain phthalates, and human exposure to certain of these phthalates has been associated with various adverse health effects. The aim of the present study has been to determine the concentrations of the metabolites of diethyl phthalate (DEP), di......(n-butyl) phthalate (DnBP), di(iso-butyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) in urine samples from 441 Danish children (3–6 years old). These children were subjects in the Danish Indoor Environment and Children's Health study. As part of each child's medical...... examination, a sample from his or her first morning urination was collected. These samples were subsequently analyzed for metabolites of the targeted phthalates. The measured concentrations of each metabolite were approximately log-normally distributed, and the metabolite concentrations significantly...

  4. Structure-activity relationship of immunostimulatory effects of phthalates

    Directory of Open Access Journals (Sweden)

    Nielsen Gunnar D

    2008-10-01

    Full Text Available Abstract Background Some chemicals, including some phthalate plasticizers, have been shown to have an adjuvant effect in mice. However, an adjuvant effect, defined as an inherent ability to stimulate the humoral immune response, was only observed after exposure to a limited number of the phthalates. An adjuvant effect may be due to the structure or physicochemical characteristics of the molecule. The scope of this study was to investigate which molecular characteristics that determine the observed adjuvant effect of the most widely used phthalate plasticizer, the di-(2-ethylhexyl phthalate (DEHP, which is documented as having a strong adjuvant effect. To do so, a series of nine lipophilic compounds with structural and physicochemical relations to DEHP were investigated. Results Adjuvant effect of phthalates and related compounds were restricted to the IgG1 antibody formation. No effect was seen on IgE. It appears that lipophilicity plays a crucial role, but lipophilicity does not per se cause an adjuvant effect. In addition to lipophilicity, a phthalate must also possess specific stereochemical characteristics in order for it to have adjuvant effect. Conclusion The adjuvant effect of phthalates are highly influenced by both stereochemical and physico-chemical properties. This knowledge may be used in the rational development of plasticizers without adjuvant effect as well as in the design of new immunological adjuvants.

  5. Association Between Urinary Phthalates and Pubertal Timing in Chinese Adolescents

    Directory of Open Access Journals (Sweden)

    Huijing Shi

    2015-09-01

    Full Text Available Background: Phthalates are synthetic chemicals and ubiquitous environmental contaminants, with hormonal activity that may alter the course of pubertal development in children. Objectives: To determine whether exposure to phthalate metabolites is associated with timing of pubertal development in a cross-sectional study of a school-based clustered sample of 503 children from a suburban district in Shanghai, China, who were 7–14 years of age at enrollment (2010 October to November. Methods: We analyzed six phthalate metabolites in urine samples by isotope-dilution liquid chromatography tandem mass spectrometry. The associations of exposures to phthalates with pubertal timing of testes, breast, and pubic hair development (represented as Tanner stages were evaluated using an ordered logistic regression model adjusted for chronological age, body fat proportion (BF%, and parental education. Results: In boys, urinary mono-n-butyl phthalate (MBP levels were negatively associated with testicular volume, and mono (2-ethyl-5-hydroxyhexyl phthalate (MEHHP and mono (2-ethyl-5-oxohexyl phthalate (MEOHP levels were negatively associated with pubic hair stages. The odds of being in an advanced stage were decreased by 43%–51%. In girls, mono (2-ethylhexyl phthalate (MEHP, MEHHP, and MEOHP levels, as well as the sum of these levels, were positively associated with breast stages, and the association was much stronger in girls with high BF%; the odds of being in an advanced stage were increase by 29% to 50%. Conclusions: Phthalate metabolites investigated in this study show significant associations with pubertal timing both in boys and in girls, especially among girls with high BF%.

  6. [Toxicity effects of phthalate substitute plasticizers used in toys].

    Science.gov (United States)

    Hirata-Koizumi, Mutsuko; Takahashi, Mika; Matsumoto, Mariko; Kawamura, Tomoko; Ono, Atsushi; Hirose, Akihiko

    2012-01-01

    Phthalate esters are widely used as plasticizers in polyvinyl chloride products. Because of human health concerns, regulatory authorities in Japan, US, Europe and other countries control the use of di(2-ethylhexyl) phthalate, diisononyl phthalate, di-n-butyl phthalate, butylbenzyl phthalate, diisodecyl phthalate and di-n-octyl phthalate for the toys that can be put directly in infants' mouths. While these regulatory actions will likely reduce the usage of phthalate esters, there is concern that other plasticizers that have not been sufficiently evaluated for safety will be used more frequently. We therefore collected and evaluated the toxicological information on di(2-ethylhexyl) terephthalate (DEHT), 1,2-cyclohexanedicarboxylic acid, diisononyl ester (DINCH), diisononyl adipate (DINA), 2,2,4-trimetyl-1,3-pentanediol diisobutyrate (TXIB), tri-n-butyl citrate (TBC) and acetyl tri-n-butyl citrate (ATBC) which were detected at a relatively high frequency in toys. The collected data have shown that chronic exposure to DEHT affects the eye and nasal turbinate, and DINCH exerts effects on the thyroid and kidney in rats. DINA and TXIB have been reported to have hepatic and renal effects in dogs or rats, and ATBC slightly affected the liver in rats. The NOAELs for repeated dose toxicity are relatively low for DINCH (40 mg/kg bw/day) and TXIB (30 mg/kg bw/day) compared with DEHT, DINA and ATBC. DEHT, TXIB and ATBC have been reported to have reproductive/developmental effects at relatively high doses in rats. For DINA and TBC, available data are insufficient for assessing the hazards, and therefore, adequate toxicity studies should be conducted. In the present review, the toxicity information on 6 alternatives to phthalate plasticizers is summarized, focusing on the effects after oral exposure, which is the route of most concern.

  7. Photoluminescence of anti-modulation doped near-surface GaAs/AlGaAs single quantum well structures exposed to hydrogen plasma

    CERN Document Server

    Bumaj, Y A; Goldkhan, R; Shtajn, N; Golombek, A; Nakov, V; Cheng, T S

    2002-01-01

    The anti-modulation Si-doped GaAs/AlGaAs structures with near-surface single quantum wells grown by molecular-beam epitaxy were exposed to hydrogen plasma at 260 deg C and investigated by low-temperature photoluminescence, photoluminescence excitation and photoreflectance spectroscopy. After hydrogenation, the quenching of the exciton luminescence for the below AlGaAs band gap excitation due to the increase of electric field in the structure has been observed. The effect is consistent with unpinning of Fermi level from mid gap of nominally undoped (p-type) GaAs cap layer due to passivation of surface states by hydrogen without neutralization of shallow impurities in the epilayers

  8. Possible impact of phthalates on infant reproductive health

    DEFF Research Database (Denmark)

    Poulsen, Grete Lottrup; Andersson, A-M; Leffers, H

    2006-01-01

    Phthalates adversely affect the male reproductive system in animals, inducing hypospadias, cryptorchidism, reduced testosterone production and decreased sperm counts. Phthalate effects are much more severe after in utero than adult exposure. Little is known about human health effects. This study...... with small AGI showed a high prevalence of cryptorchidism and small genital size. Taken together these studies suggest an antivirilizing effect of phthalates in infants. Most of these findings are in line with animal observations. However, the possible effects of MEP appear to be limited to humans. This may...

  9. Prenatal phthalate exposures and anogenital distance in Swedish boys

    DEFF Research Database (Denmark)

    Bornehag, Carl-Gustaf; Carlstedt, Fredrik; Jönsson, Bo Ag

    2015-01-01

    BACKGROUND: Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Because of reported health risks, diisononyl phthalate (DiNP) has been introduced as a replacement for di(2-ethylhexyl) phthalate (DEHP) in soft PVC. This raises concerns...... because animal data suggest that DiNP may have antiandrogenic properties similar to those of DEHP. The anogenital distance (AGD)-the distance from the anus to the genitals-has been used to assess reproductive toxicity. OBJECTIVE: The objective of this study was to examine the associations between prenatal...

  10. Single-catalyst high-weight% hydrogen storage in an N-heterocycle synthesized from lignin hydrogenolysis products and ammonia.

    Science.gov (United States)

    Forberg, Daniel; Schwob, Tobias; Zaheer, Muhammad; Friedrich, Martin; Miyajima, Nobuyoshi; Kempe, Rhett

    2016-10-20

    Large-scale energy storage and the utilization of biomass as a sustainable carbon source are global challenges of this century. The reversible storage of hydrogen covalently bound in chemical compounds is a particularly promising energy storage technology. For this, compounds that can be sustainably synthesized and that permit high-weight% hydrogen storage would be highly desirable. Herein, we report that catalytically modified lignin, an indigestible, abundantly available and hitherto barely used biomass, can be harnessed to reversibly store hydrogen. A novel reusable bimetallic catalyst has been developed, which is able to hydrogenate and dehydrogenate N-heterocycles most efficiently. Furthermore, a particular N-heterocycle has been identified that can be synthesized catalytically in one step from the main lignin hydrogenolysis product and ammonia, and in which the new bimetallic catalyst allows multiple cycles of high-weight% hydrogen storage.

  11. MEASUREMENT OF PHTHALATE LEVELS IN HUMAN MILK: CONTRIBUTION FROM PLASTICS IN BREAST PUMPS, STORAGE BOTTLES AND BAGS

    Science.gov (United States)

    Phthalates are plasticizers used to impart flexibility in products widely used by the general population, including polyvinyl chloride, plastic toys, and medical devices. Some phthalates act as anti-androgens, and prenatal or perinatal exposure to phthalates in laboratory animals...

  12. Hydrogenation of the alpha,beta-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and Prenal over Pt Single Crystals: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

    Energy Technology Data Exchange (ETDEWEB)

    Kliewer, C.J.; Somorjai, G.A.

    2008-11-26

    Sum-frequency generation vibrational spectroscopy (SFG-VS) and kinetic measurements using gas chromatography have been used to study the surface reaction intermediates during the hydrogenation of three {alpha},{beta}-unsaturated aldehydes, acrolein, crotonaldehyde, and prenal, over Pt(111) at Torr pressures (1 Torr aldehyde, 100 Torr hydrogen) in the temperature range of 295K to 415K. SFG-VS data showed that acrolein has mixed adsorption species of {eta}{sub 2}-di-{sigma}(CC)-trans, {eta}{sub 2}-di-{sigma}(CC)-cis as well as highly coordinated {eta}{sub 3} or {eta}{sub 4} species. Crotonaldehyde adsorbed to Pt(111) as {eta}{sub 2} surface intermediates. SFG-VS during prenal hydrogenation also suggested the presence of the {eta}{sub 2} adsorption species, and became more highly coordinated as the temperature was raised to 415K, in agreement with its enhanced C=O hydrogenation. The effect of catalyst surface structure was clarified by carrying out the hydrogenation of crotonaldehyde over both Pt(111) and Pt(100) single crystals while acquiring the SFG-VS spectra in situ. Both the kinetics and SFG-VS showed little structure sensitivity. Pt(100) generated more decarbonylation 'cracking' product while Pt(111) had a higher selectivity for the formation of the desired unsaturated alcohol, crotylalcohol.

  13. Reaction pathway and oxidation mechanisms of dibutyl phthalate by persulfate activated with zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huanxuan [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); Wan, Jinquan, E-mail: ppjqwan@scut.edu.cn [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); State Key Lab Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Ma, Yongwen [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); State Key Lab Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Yan [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China)

    2016-08-15

    This study investigated reaction pathway and oxidation mechanisms of dibutyl phthalate (DBP) by persulfate (PS) activated with zero-valent iron (ZVI). The DBP degradation was studied at three pH values (acidic, neutral and basic) in the presence of different organic scavengers. Using a chemical probe method, both sulfate radical (SO{sub 4}·{sup −}) and hydroxyl radical (·OH) were found to be primary oxidants at pH 3.0 and pH 7.0, respectively while ·OH was the major specie to oxidize DBP at pH 11.0. A similar result was found in an experiment of Electron Spin Resonance spin-trapping where in addition to ·OH, superoxide radical (O{sub 2}·{sup −}) was detected at pH 11.0. The transformation of degradation products including dimethyl phthalate (DMP), diethyl phthalate (DEP), phthalic anhydride, and acetophenone exhibited diverse variation during the reaction processes. The phthalic anhydride concentration appeared to be maximum at all pHs. Another eleven intermediate products were also found at pH 3.0 by GC–MS and HPLC analysis, and their degradation mechanisms and pathways were proposed. It was suggested that dealkylation, hydroxylation, decarboxylation and hydrogen extraction were the dominant degradation mechanisms of DBP at pH 3.0. - Highlights: • Both SO{sub 4}{sup −}· and ·OH were found to be the major active species at pH 3.0 and pH 7.0. • ·OH and ·O2– were the primary oxidants pH 11.0. • The intermediate products were investigated as well as the degradation pathway. • Dealkylation, hydroxylation, decarboxylation, H-extraction were the major mechanisms.

  14. Cathepsin B inhibitory activities of three new phthalate derivatives isolated from seahorse, Hippocampus Kuda Bleeler.

    Science.gov (United States)

    Li, Yong; Qian, Zhong-Ji; Kim, Se-Kwon

    2008-12-01

    Three new phthalate acid derivatives, 2,12-diethyl-11-methylhexadecyl 2-ethyl-11-methylhexadecyl phthalate (1), 2-ethyldecyl 2-ethylundecyl phthalate (2), and bis(2-ethyldodecyl) phthalate (3), were isolated from seahorse, Hippocampus Kuda Bleeler, together with a known natural analog bis(2-ethylheptyl) phthalate (4). The structures of these compounds were elucidated mainly by means of the comprehensive analysis of their NMR spectroscopic data. The four phthalate derivatives showed dose-dependent cathepsin B inhibitions activities with IC(50) values of 0.13 mM (1), 0.21 mM (2), 0.18 mM (3), and 0.29 mM (4), respectively.

  15. Isolation and Characterization of Bis (2 – Methoxyethyl) Phthalate ...

    African Journals Online (AJOL)

    Isolation and Characterization of Bis (2 – Methoxyethyl) Phthalate and Hexashydro-1 3 – Dimethyl – 4 – Phenyl – 1h – Azepine 4 – Carboxylic Acid from the Root of Cissampelos Owariensis (P. Beauv)

  16. Gas Chromatographic Analysis of Sulfur Mustard in Diethyl Phthalate

    National Research Council Canada - National Science Library

    Lancaster, Paul

    1998-01-01

    ...) that had been trapped in the solvent, diethyl phthalate (DEP) is described. The method utilises the improved sensitivity and selectivity offered by the new Pulsed Flame Photometric Detector to detect routinely samples containing...

  17. Evaluation of the levels of phthalate ester plasticizers in surface ...

    African Journals Online (AJOL)

    Evaluation of the levels of phthalate ester plasticizers in surface water of Ethiope ... Gas chromatography (GC) coupled with mass spectrometer (MS) was used to ... with their common use in plastic materials and other industrial chemicals.

  18. Technique for rapid detection of phthalates in water and beverages

    KAUST Repository

    Zia, Asif I.; Rahman, Mohammed Syaifudin Abdul; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Al-Bahadly, Ibrahim H.; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen; Liao, Taishan

    2013-01-01

    The teratogenic and carcinogenic effects of phthalate esters on living beings are proven in toxicology studies. These ubiquitous food and environmental pollutants pose a great danger to the human race due to their extraordinary use as a plasticizer

  19. Success and failure with phthalate buffers in capillary zone electrophoresis

    NARCIS (Netherlands)

    Bocek, P.; Gebauer, P.; Beckers, J.L.

    2001-01-01

    Phthalate buffers are currently used in capillary electrophoresis as robust electrolyte systems for indirect detection. This contribution demonstrates that these buffers show regularly not only successful regions of mobilities of analytes (sample window) but also regions of failure where the

  20. Phthalate-induced testicular dysgenesis syndrome: Leydig cell influence.

    Science.gov (United States)

    Hu, Guo-Xin; Lian, Qing-Quan; Ge, Ren-Shan; Hardy, Dianne O; Li, Xiao-Kun

    2009-04-01

    Phthalates, the most abundantly produced plasticizers, leach out from polyvinyl chloride plastics and disrupt androgen action. Male rats that are exposed to phthalates in utero develop symptoms characteristic of the human condition referred to as testicular dysgenesis syndrome (TDS). Environmental influences have been suspected to contribute to the increasing incidence of TDS in humans (i.e. cryptorchidism and hypospadias in newborn boys and testicular cancer and reduced sperm quality in adult males). In this review, we discuss the recent findings that prenatal exposure to phthalates affects Leydig cell function in the postnatal testis. This review also focuses on the recent progress in our understanding of how Leydig cell factors contribute to phthalate-mediated TDS.

  1. Photoelectron spectroscopy and density functional theory studies of (FeS)mH- (m = 2-4) cluster anions: effects of the single hydrogen.

    Science.gov (United States)

    Yin, Shi; Bernstein, Elliot R

    2017-12-20

    Single hydrogen containing iron hydrosulfide cluster anions (FeS) m H - (m = 2-4) are studied by photoelectron spectroscopy (PES) at 3.492 eV (355 nm) and 4.661 eV (266 nm) photon energies, and by Density Functional Theory (DFT) calculations. The structural properties, relative energies of different spin states and isomers, and the first calculated vertical detachment energies (VDEs) of different spin states for these (FeS) m H - (m = 2-4) cluster anions are investigated at various reasonable theory levels. Two types of structural isomers are found for these (FeS) m H - (m = 2-4) clusters: (1) the single hydrogen atom bonds to a sulfur site (SH-type); and (2) the single hydrogen atom bonds to an iron site (FeH-type). Experimental and theoretical results suggest such available different SH- and FeH-type structural isomers should be considered when evaluating the properties and behavior of these single hydrogen containing iron sulfide clusters in real chemical and biological systems. Compared to their related, respective pure iron sulfur (FeS) m - clusters, the first VDE trend of the diverse type (FeS) m H 0,1 - (m = 1-4) clusters can be understood through (1) the different electron distribution properties of their highest singly occupied molecular orbital employing natural bond orbital analysis (NBO/HSOMO), and (2) the partial charge distribution on the NBO/HSOMO localized sites of each cluster anion. Generally, the properties of the NBO/HSOMOs play the principal role with regard to the physical and chemical properties of all the anions. The change of cluster VDE from low to high is associated with the change in nature of their NBO/HSOMO from a dipole bound and valence electron mixed character, to a valence p orbital on S, to a valence d orbital on Fe, and to a valence p orbital on Fe or an Fe-Fe delocalized valence bonding orbital. For clusters having the same properties for NBO/HSOMOs, the partial charge distributions at the NBO/HSOMO localized sites additionally

  2. Investigation of the source of residual phthalate in sundried salt.

    Science.gov (United States)

    Kim, Jin Hyo; Lee, Jin Hwan; Kim, So-Young

    2014-03-01

    Phthalate contamination in sundried salt has recently garnered interest in Korea. Phthalate concentrations were investigated in Korean sundried salts, source waters, and aqueous extracts from polyvinyl chloride materials used in salt ponds. Preliminary screening results for phthalates in Korean sundried salts revealed that only di(2-ethylhexyl)phthalate (DEHP) was over the limit of detection, with an 8.6% detection rate, and the concentration ranged from below the limit of detection to 0.189 mg/kg. The tolerable daily intake contribution ratio of the salt was calculated to be only 0.001%. Residual phthalates were below 0.026 mg/liter in source water, and the aqueous extracted di-n-butylphthalate, benzylbutylphthalate, and DEHP, which are considered endocrine disruptors, were below 0.029 mg/kg as derived from the polyvinyl chloride materials in salt ponds. The transfer ratios of the six phthalates from seawater to sundried salts were investigated; transfer ratio was correlated with vapor pressure (r(2) = 0.9875). Thus, di-n-butylphthalate, benzylbutylphthalate, DEHP, and di-n-octylphthalate can be considered highly likely residual pollutants in some consumer salts.

  3. Request from the Phthalate Esters Panel of the American Chemistry Council for correction of EPA's Action Plan for Phthalate Esters

    Science.gov (United States)

    The Phthalate Esters Panel (Panel) of the American Chemistry Council submits this Request for Correction to EPA under the Guidelines for Ensuring and Maximizing the Quality, Objectivity, Utility, and Integrity, of Information Disseminated by the Environmental Protection Agency

  4. Childhood Exposure to Phthalates: Associations with Thyroid Function, Insulin-like Growth Factor I, and Growth

    Science.gov (United States)

    Boas, Malene; Frederiksen, Hanne; Feldt-Rasmussen, Ulla; Skakkebæk, Niels E.; Hegedüs, Laszlo; Hilsted, Linda; Juul, Anders; Main, Katharina M.

    2010-01-01

    Background Phthalates are widely used chemicals, and human exposure is extensive. Recent studies have indicated that phthalates may have thyroid-disrupting properties. Objective We aimed to assess concentrations of phthalate metabolites in urine samples from Danish children and to investigate the associations with thyroid function, insulin-like growth factor I (IGF-I), and growth. Methods In 845 children 4–9 years of age, we determined urinary concentrations of 12 phthalate metabolites and serum levels of thyroid-stimulating hormone, thyroid hormones, and IGF-I. Results Phthalate metabolites were detected in all urine samples, of which monobutyl phthalate was present in highest concentration. Phthalate metabolites were negatively associated with serum levels of free and total triiodothyronine, although statistically significant primarily in girls. Metabolites of di(2-ethylhexyl) phthalate and diisononyl phthalate were negatively associated with IGF-I in boys. Most phthalate metabolites were negatively associated with height, weight, body surface, and height gain in both sexes. Conclusions Our study showed negative associations between urinary phthalate concentrations and thyroid hormones, IGF-I, and growth in children. Although our study was not designed to reveal the mechanism of action, the overall coherent negative associations between urine phthalate and thyroid and growth parameters may suggest causative negative roles of phthalate exposures for child health. PMID:20621847

  5. Consumer product exposures associated with urinary phthalate levels in pregnant women

    Science.gov (United States)

    Buckley, Jessie P.; Palmieri, Rachel T.; Matuszewski, Jeanine M.; Herring, Amy H.; Baird, Donna D.; Hartmann, Katherine E.; Hoppin, Jane A.

    2012-01-01

    Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18–38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors were statistically significantly associated with phthalate levels. Individuals who used nail polish had higher levels of mono-butyl phthalate (p=0.048) than non-users. Mono-benzyl phthalate levels were higher among women who used eye makeup (p=0.034) or used makeup on a regular basis (p=0.004). Women who used cologne or perfume had higher levels of di-(2-ethylhexyl) phthalate metabolites. Household products, home flooring or paneling, and other personal care products were also associated with urinary phthalates. The proportion of variance in metabolite concentrations explained by questionnaire items ranged between 0.31 for mono-ethyl phthalate and 0.42 for mono-n-methyl phthalate. Although personal care product use may be an important predictor of urinary phthalate levels, most of the variability in phthalate exposure was not captured by our relatively comprehensive set of questionnaire items. PMID:22760436

  6. Equilibrium and heat of adsorption of diethyl phthalate on heterogeneous adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.M.; Xu, Z.W.; Pan, B.C.; Hong, C.H.; Jia, K.; Jiang, P.J.; Zhang, Q.J.; Pan, B.J. [Nanjing University, Nanjing (China)

    2008-09-15

    Removal of phthalate esters from water has been of considerable concern recently. In the present study, the adsorptive removal performance of diethyl phthalate (DEP) from water was investigated with the aminated polystyrene resin (NDA-101) and oxidized polystyrene resin (NDA-702). In addition, the commercial homogeneous polystyrene resin (XAD-4) and acrylic ester resin (Amberlite XAD-7) as well as coal-based granular activated carbon (AC-750) were chosen for comparison. The corresponding equilibrium isotherms are well described by the Freundlich equation and the adsorption capacities for DEP followed the order NDA-702 > NDA-101 > AC-750 > XAD-4 > XAD-7. Analysis of adsorption mechanisms suggested that these adsorbents spontaneously adsorb DEP molecules driven mainly by enthalpy change, and the adsorption process was derived by multiple adsorbent-adsorbate interactions such as hydrogen bonding, {pi}-{pi} stacking, and micropore filling. The information related to the adsorbent surface heterogeneity and the adsorbate-adsorbate interaction was obtained by Do's model. All the results indicate that heterogeneous resins NDA-702 and NDA-101 have excellent potential as an adsorption material for the removal of DEP from the contaminated water.

  7. Hydrogenation of Phenylacetylene to Styrene on Pre-C_xH_y- and C-Covered Cu(111) Single Crystal Catalysts

    International Nuclear Information System (INIS)

    Sohn, Young Ku; Wei, Wei; White, John M.

    2011-01-01

    Thermal hydrogenation of phenylacetylene (PA, C_8H_6) to styrene (C_8H_8) on pre-C_xH_y- and C-covered Cu(111) single crystal substrates has been studied using temperature-programmed desorption (TPD) mass spectrometry. Chemisorbed PA with an acetylene group has been proved to be associated with hydrogen of pre-adsorbed C_xH_y to form styrene (104 amu) on Cu surface. For the parent (PA) mass (102 amu) TPD profile, the TPD peaks at 360 K and 410 K are assigned to chemisorbed vertically aligned PA and flat-lying cross-bridged PA, respectively (J. Phys. Chem. C 2007, 111, 5101). The relative I_3_6_0_K/I_4_1_0_K TPD ratio dramatically increases with increasing pre-adsorbed C_xH_y before dosing PA, while the ratio does not increase for pre-C-covered surface. For PA on pre-C_xH_y-covered Cu(111) surface, styrene desorption is enhanced relative to the parent PA desorption, while styrene formation is dramatically quenched on pre-C-covered (lack of adsorbed hydrogen nearby) surface. It appears that only cross-bridged PA associates with adsorbed hydrogen to form styrene that promptly desorbs at 410 K, while vertically aligned PA is less likely to participate in forming styrene

  8. Hydrogenation of Phenylacetylene to Styrene on Pre-C{sub x}H{sub y}- and C-Covered Cu(111) Single Crystal Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Ku [Yeungnam University, Gyeongsan (Korea, Republic of); Wei, Wei; White, John M. [The University of Texas at Austin, Texas (United States)

    2011-05-15

    Thermal hydrogenation of phenylacetylene (PA, C{sub 8}H{sub 6}) to styrene (C{sub 8}H{sub 8}) on pre-C{sub x}H{sub y}- and C-covered Cu(111) single crystal substrates has been studied using temperature-programmed desorption (TPD) mass spectrometry. Chemisorbed PA with an acetylene group has been proved to be associated with hydrogen of pre-adsorbed C{sub x}H{sub y} to form styrene (104 amu) on Cu surface. For the parent (PA) mass (102 amu) TPD profile, the TPD peaks at 360 K and 410 K are assigned to chemisorbed vertically aligned PA and flat-lying cross-bridged PA, respectively (J. Phys. Chem. C 2007, 111, 5101). The relative I{sub 360K}/I{sub 410K} TPD ratio dramatically increases with increasing pre-adsorbed C{sub x}H{sub y} before dosing PA, while the ratio does not increase for pre-C-covered surface. For PA on pre-C{sub x}H{sub y}-covered Cu(111) surface, styrene desorption is enhanced relative to the parent PA desorption, while styrene formation is dramatically quenched on pre-C-covered (lack of adsorbed hydrogen nearby) surface. It appears that only cross-bridged PA associates with adsorbed hydrogen to form styrene that promptly desorbs at 410 K, while vertically aligned PA is less likely to participate in forming styrene.

  9. Phthalate-induced toxicity: Identifying the vulnerable pathways during sexual differentiation in the male rat

    Science.gov (United States)

    Human exposures to phthalate ester plasticizer compounds are widespread. Studies in rodents have demonstrated that in utero exposure to various phthalates throughout sexual differentiation (GD14-18) results in decreased fetal testicular androgen production, and ultimately leads t...

  10. Phthalate Esters and Reproductive Toxicity** Presentation requested by State of Mass Use Reductions Committee-TURI

    Science.gov (United States)

    Phthalate esters and reproductive toxicity the presentation described the uses of phthalates, the toxicity to mammals with a focus on reproductive toxicity and the potency of these chemicals to disrupt mammalian reproductive development in utero

  11. Microscopic models for proton transfer in water and strongly hydrogen-bonded complexes with a single-well proton potential

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2004-01-01

    A new mechanism and formalism for proton transfer in donor-acceptor complexes with long hydrogen bonds introduced recently [1], is applied to a proton transfer in liquid water. "Structural diffusion" of hydroxonium ions is regarded as totally adiabatic process, with synchronous hindered translation...... of two closest water molecules to and from the reaction complex as crucial steps. The water molecules induce a "gated" shift of the proton from the donor to the acceptor in the double-well potential with simultaneous breaking/formation of hydrogen bonds between these molecules and the proton donor...... and acceptor. The short-range and long-range proton transfer as "structural diffusion" of Zundel complexes is also considered. The theoretical formalism is illustrated with the use of Morse, exponential, and harmonic molecular potentials. This approach is extended to proton transfer in strongly hydrogen...

  12. Single and double carbon vacancies in pyrene as first models for graphene defects: A survey of the chemical reactivity toward hydrogen

    Science.gov (United States)

    Nieman, Reed; Das, Anita; Aquino, Adélia J. A.; Amorim, Rodrigo G.; Machado, Francisco B. C.; Lischka, Hans

    2017-01-01

    Graphene is regarded as one of the most promising materials for nanoelectronics applications. Defects play an important role in modulating its electronic properties and also enhance its chemical reactivity. In this work the reactivity of single vacancies (SV) and double vacancies (DV) in reaction with a hydrogen atom Hr is studied. Because of the complicated open shell electronic structures of these defects due to dangling bonds, multireference configuration interaction (MRCI) methods are being used in combination with a previously developed defect model based on pyrene. Comparison of the stability of products derived from Csbnd Hr bond formation with different carbon atoms of the different polyaromatic hydrocarbons is made. In the single vacancy case the most stable structure is the one where the incoming hydrogen is bound to the carbon atom carrying the dangling bond. However, stable Csbnd Hr bonded structures are also observed in the five-membered ring of the single vacancy. In the double vacancy, most stable bonding of the reactant Hr atom is found in the five-membered rings. In total, Csbnd Hr bonds, corresponding to local energy minimum structures, are formed with all carbon atoms in the different defect systems and the pyrene itself. Reaction profiles for the four lowest electronic states show in the case of a single vacancy a complex picture of curve crossings and avoided crossings which will give rise to a complex nonadiabatic reaction dynamics involving several electronic states.

  13. Urinary concentrations of phthalates and phenols in a population of Spanish pregnant women and children.

    Science.gov (United States)

    Casas, Lidia; Fernández, Mariana F; Llop, Sabrina; Guxens, Mònica; Ballester, Ferran; Olea, Nicolás; Irurzun, Mikel Basterrechea; Rodríguez, Loreto Santa Marina; Riaño, Isolina; Tardón, Adonina; Vrijheid, Martine; Calafat, Antonia M; Sunyer, Jordi

    2011-07-01

    Phthalate and phenol exposure is prevalent among the general population and of potential concern for pregnant women and children because of their suspected susceptibility to endocrine effects. To evaluate the extent of exposure to several phthalates and phenols in a sample of Spanish pregnant women - according to their individual characteristics (age, social class, education, and body mass index) - and children who participated in the INMA - Infancia y Medio Ambiente (Environment and Childhood) project. One spot urine sample was taken during the third trimester of pregnancy from 120 pregnant women and from 30 4-year old children belonging to 5 Spanish birth cohorts, and analyzed for 11 phthalate metabolites and 9 phenols. Three metabolites of di(2-ethylhexyl) phthalate, mono-2-ethyl-5-carboxypentyl phthalate, mono-2-ethyl-5-hydroxyhexyl phthalate, and mono-2-ethyl-5-oxohexyl phthalate; two metabolites of dibutyl phthalates, mono-isobutyl phthalate and mono-n-butyl phthalate; monoethyl phthalate (MEP), the main metabolite of diethyl phthalate; and two phenols, methyl paraben (M-PB) and 2,5-dichlorophenol were detected in the urine samples of all women. The highest urinary concentrations were for MEP and M-PB. Urinary concentrations of all phthalate metabolites and of 2,4-dichlorophenol, 2,5-dichlorophenol, and bisphenol A were lower in the pregnant women than in the children. Among women, a positive relationship with social class and education was shown for most of the phthalate metabolites and phenols. Almost all phthalate metabolites varied by region even after adjusting for social class and education. Phthalate and phenol exposures are prevalent in a group of pregnant women and young children, two susceptible populations, and these exposures might be positively related to social class. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Benzoate Catabolite Repression of the Phthalate Degradation Pathway in Rhodococcus sp. Strain DK17▿

    OpenAIRE

    Choi, Ki Young; Zylstra, Gerben J.; Kim, Eungbin

    2006-01-01

    Rhodococcus sp. strain DK17 exhibits a catabolite repression-like response when provided simultaneously with benzoate and phthalate as carbon and energy sources. Benzoate in the medium is depleted to detection limits before the utilization of phthalate begins. The transcription of the genes encoding benzoate and phthalate dioxygenase paralleled the substrate utilization profile. Two mutant strains with defective benzoate dioxygenases were unable to utilize phthalate in the presence of benzoat...

  15. Consumer product exposures associated with urinary phthalate levels in pregnant women

    OpenAIRE

    Buckley, Jessie P.; Palmieri, Rachel T.; Matuszewski, Jeanine M.; Herring, Amy H.; Baird, Donna D.; Hartmann, Katherine E.; Hoppin, Jane A.

    2012-01-01

    Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18–38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors...

  16. Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

    International Nuclear Information System (INIS)

    Christen, Verena; Crettaz, Pierre; Oberli-Schrämmli, Aurelia; Fent, Karl

    2012-01-01

    Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC 10 , EC 25 and EC 50 in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC 10 mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC 25 mixture of DBP + BPA. A ternary mixture revealed synergism at the EC 50 , and weak antagonistic activity at the EC 25 level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.

  17. Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Crettaz, Pierre; Oberli-Schrämmli, Aurelia [Swiss Federal Office of Public Health, Division Chemical Products, 3003 Bern (Switzerland); Fent, Karl, E-mail: karl.fent@bluewin.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich (ETH Zürich), Department of Environmental Sciences, 8092 Zürich (Switzerland)

    2012-03-01

    Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC{sub 10}, EC{sub 25} and EC{sub 50} in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC{sub 10} mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC{sub 25} mixture of DBP + BPA. A ternary mixture revealed synergism at the EC{sub 50}, and weak antagonistic activity at the EC{sub 25} level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.

  18. Toxicity and Estrogenic Endocrine Disrupting Activity of Phthalates and Their Mixtures

    Directory of Open Access Journals (Sweden)

    Xueping Chen

    2014-03-01

    Full Text Available Phthalates, widely used in flexible plastics and consumer products, have become ubiquitous contaminants worldwide. This study evaluated the acute toxicity and estrogenic endocrine disrupting activity of butyl benzyl phthalate (BBP, di(n-butyl phthalate (DBP, bis(2-ethylhexyl phthalate (DEHP, diisodecyl phthalate (DIDP, diisononyl phthalate (DINP, di-n-octyl phthalate (DNOP and their mixtures. Using a 72 h zebrafish embryo toxicity test, the LC50 values of BBP, DBP and a mixture of the six phthalates were found to be 0.72, 0.63 and 0.50 ppm, respectively. The other four phthalates did not cause more than 50% exposed embryo mortality even at their highest soluble concentrations. The typical toxicity symptoms caused by phthalates were death, tail curvature, necrosis, cardio edema and no touch response. Using an estrogen-responsive ChgH-EGFP transgenic medaka (Oryzias melastigma eleutheroembryos based 24 h test, BBP demonstrated estrogenic activity, DBP, DEHP, DINP and the mixture of the six phthalates exhibited enhanced-estrogenic activity and DIDP and DNOP showed no enhanced- or anti-estrogenic activity. These findings highlighted the developmental toxicity of BBP and DBP, and the estrogenic endocrine disrupting activity of BBP, DBP, DEHP and DINP on intact organisms, indicating that the widespread use of these phthalates may cause potential health risks to human beings.

  19. Validation of an automated counting procedure for phthalate-induced testicular multinucleated germ cells.

    Science.gov (United States)

    Spade, Daniel J; Bai, Cathy Yue; Lambright, Christy; Conley, Justin M; Boekelheide, Kim; Gray, L Earl

    2018-06-15

    In utero exposure to certain phthalate esters results in testicular toxicity, characterized at the tissue level by induction of multinucleated germ cells (MNGs) in rat, mouse, and human fetal testis. Phthalate exposures also result in a decrease in testicular testosterone in rats. The anti-androgenic effects of phthalates have been more thoroughly quantified than testicular pathology due to the significant time requirement associated with manual counting of MNGs on histological sections. An automated counting method was developed in ImageJ to quantify MNGs in digital images of hematoxylin-stained rat fetal testis tissue sections. Timed pregnant Sprague Dawley rats were exposed by daily oral gavage from gestation day 17 to 21 with one of eight phthalate test compounds or corn oil vehicle. Both the manual counting method and the automated image analysis method identified di-n-butyl phthalate, butyl benzyl phthalate, dipentyl phthalate, and di-(2-ethylhexyl) phthalate as positive for induction of MNGs. Dimethyl phthalate, diethyl phthalate, the brominated phthalate di-(2-ethylhexyl) tetrabromophthalate, and dioctyl terephthalate were negative. The correlation between automated and manual scoring metrics was high (r = 0.923). Results of MNG analysis were consistent with these compounds' anti-androgenic activities, which were confirmed in an ex vivo testosterone production assay. In conclusion, we have developed a reliable image analysis method that can be used to facilitate dose-response studies for the reproducible induction of MNGs by in utero phthalate exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. PVC flooring is related to human uptake of phthalates in infants.

    Science.gov (United States)

    Carlstedt, F; Jönsson, B A G; Bornehag, C-G

    2013-02-01

    Polyvinyl chloride (PVC) flooring material contains phthalates, and it has been shown that such materials are important sources for phthalates in indoor dust. Phthalates are suspected endocrine-disrupting chemicals (EDCs). Consecutive infants between 2 and 6 months old and their mothers were invited. A questionnaire about indoor environmental factors and family lifestyle was used. Urinary metabolites of the phthalates diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBzP), and dietylhexyl phthalate (DEHP) were measured in the urine of the children. Of 209 invited children, 110 (52%) participated. Urine samples were obtained from 83 of these. Urine levels of the BBzP metabolite monobenzyl phthalate (MBzP) was significantly higher in infants with PVC flooring in their bedrooms (P flooring material may increase the human uptake of phthalates in infants. Urinary levels of phthalate metabolites during early life are associated with the use of PVC flooring in the bedroom, body area, and the use of infant formula. This study shows that the uptake of phthalates is not only related to oral uptake from, for example, food but also to environmental factors such as building materials. This new information should be considered when designing indoor environment, especially for children. © 2012 John Wiley & Sons A/S.

  1. OCTANOL/WATER PARTITION COEFFICIENTS AND WATER SOLUBILITIES OF PHTHALATE ESTERS

    Science.gov (United States)

    Measurements of the octanol/water partition coefficients (K-ow) and water solubilities of di-n-octyl phthalate (DnOP) and di-n-decyl phthalate (DnDP) by the slow-stirring method are reported. The water solubility was also measured for di-n-hexyl phthalate (DnHP). The log K-ow val...

  2. 77 FR 2276 - Teleconference and Public Meeting of the Chronic Hazard Advisory Panel on Phthalates and...

    Science.gov (United States)

    2012-01-17

    ... levels of children's, pregnant women's, and others' exposure to phthalates, based upon a reasonable... 2010, and in March, July, and November 2011, at the CPSC's offices in Bethesda, MD, and by... on children's health of all phthalates and phthalate alternatives, as used in children's toys and...

  3. Effect of cooking at home on the levels of eight phthalates in foods.

    Science.gov (United States)

    Fierens, T; Vanermen, G; Van Holderbeke, M; De Henauw, S; Sioen, I

    2012-12-01

    Food products can be contaminated with toxic compounds via the environment. Another possibility of food contamination is that toxicants are generated in foods or that chemicals migrate from food contact materials into foods during processing. In this study, the effect of cooking at home on the levels of phthalates - world's most used group of plasticisers - in various food types (starchy products, vegetables and meat and fish) was examined. Eight compounds were considered, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-n-octyl phthalate (DnOP). Food products were analysed before as well as after cooking (boiling, steaming, (deep-)frying or grilling). In general, phthalate concentrations in foods declined after cooking, except in vegetables, where almost no effect was seen. Several factors influenced the degree of this decline (e.g. weight difference, fat uptake, etc.). Of all phthalates, DEHP, DiBP and BBP were affected the most. In conclusion, cooking at home definitely affected phthalate concentrations in foods and thus needs to be considered in order to correctly assess humans' dietary exposure to these contaminants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Temporal trends of cumulative risks to phthalate mixtures in the United States from 2005 to 2014

    Science.gov (United States)

    Phthalates are used in a wide range of consumer goods resulting in widespread exposures among the general population. Exposures to specific phthalates are expected to vary over time with changes in the patterns of phthalate use. We investigated the existence of trends in estimate...

  5. The characteristics of atmospheric phthalates in Shanghai: A haze case study and human exposure assessment

    Science.gov (United States)

    Li, Yingjie; Wang, Jiahui; Ren, Bainian; Wang, Hongli; Qiao, Liping; Zhu, Jiping; Li, Li

    2018-04-01

    While phthalates in indoor environments are extensively studied, reports on phthalates in outdoor air, particularly their associations with haze weather events are rare. Phthalates, especially dimethyl phthalate, are known to react with criteria air pollutants contributing to the formation of secondary organic aerosols. This study investigated phthalates levels in the atmosphere in Shanghai with a focus on their associations with different air quality weather events. The air quality during the study period was classified into three levels: non-haze, light pollution and moderate pollution. Phthalates levels were found to be lower in non-haze weather events (236 ng/m3) and higher in moderate pollution weather events (up to 700 ng/m3). Meteorological factors of relative humidity and wind speed had an inverse relationship with phthalates levels. Particulate matter had a positive correlation with phthalates levels. Hydroxyl radical initiated photo-reaction of dimethyl phthalate was evident by its inverse relationship with total atmospheric oxidant (O3 + NO2), indicating that dimethyl phthalate could be one of the precursors of secondary organic aerosol causing haze weather events. Daily intake of phthalates through exposure to outdoor air is estimated to be relatively minor; children intake remains higher on a body weight basis. This is the first study demonstrating the relationship of phthalates and different air quality conditions in haze weather events. The knowledge contributes to our understanding on the cause of haze weather events in China and elsewhere.

  6. Degradation of phthalate in aqueous solution by advanced oxidation process, photo-fenton

    International Nuclear Information System (INIS)

    Trabelsi, S.; Bellakhal, N.; Oturan, N.; Oturan, M.A.

    2009-01-01

    A photochemical method for degradation of persistent organic pollutants present in liquid effluents from the plastic industry and in the leaching described. This method, called P hoto-Fenton i nvolves the generation of radicals hydroxyl coupling between the Fenton reaction and photochemistry, OH radicals. Thus formed react with very high speeds, organic substances pollutants leading to their oxidation to total mineralization. In this study, we applied the process photo-Fenton treatment Plasticizers, Phthalates. For this, optimization of experimental parameters (namely the relationship between the concentrations of hydrogen peroxide and iron concentration catalyst) was performed. Under optimal conditions and determined the kinetics mineralization of phthalic anhydride by OH was studied. The overall results confirm the effectiveness of photo-Fenton process for the decontamination of liquid effluents responsible for persistent organic pollutants (Pop's).

  7. Monitoring phthalates in the tissues of broiler chicks with feedstuffs different phthalate contents

    Directory of Open Access Journals (Sweden)

    Alžbeta Jarošová

    2010-01-01

    Full Text Available For the monitoring of distribution and accumulation of phthalic acid esters (PAE in animal tissues, samples of muscle, mesenteric fat (fat, skin and liver from broiler chicks ROSS 308 were used. The chicks were divided into 4 groups (50 chicks each. All the chicks were given commercial diets (complete feed, KKS for broiler chicks (starter – BR1; grower – BR2 and finisher – BR3. The experimental diets were supplemented with vegetable oil (RO with low (group N or high (group V phthalate contents, or animal fat with a high phthalate content (group Z. Neither the control diets (K, nor the grower (BR1 diets contained vegetable oils or animal fat. The N chicks were given the grower (BR2 and finisher (BR3 diets supplemented with 5% and 3% vegetable oil, respectively. The V chicks were given BR2 and BR3 diets with 5% and 3% vegetable oil, respectively. The Z chicks were given BR2 and BR3 diets with 5% and 3% animal fat, respectively. Di-n-butyl phthalate (DBP and di-(2-ethylhexyl phthalate (DEHP were found in the tissues of chicks in all the experimental groups. The DBP content in the muscle ranged from 0.03 to 0.55 mg . kg−1, in the adipose tissue from < 0.20 to 2.56 mg . kg−1, in the skin from < 0.20 to 1.49 mg . kg−1, and in the liver from 0.03 to 0.13 mg . kg−1. The content of DEHP in the muscle ranged from 0.03 to 1.15 mg . kg−1, in the adipose tissue from 0.25 to 9.85 mg . kg−1, in the skin from < 0.20 to 4.68 mg . kg−1, and in the liver from 0.16 to 0.24 mg . kg−1. The highest concentrations of DBP of 1.28 ± 1.00 mg . kg−1 of fresh sample (an average value from 8 chicks was determined in the adipose tissue of V chicks. The highest concentration of DEHP of 3.27 ± 2.87 mg . kg−1 of fresh sample (mean of 8 chicks was also determined in the V group. The accumulation of DEHP was 3.2; 2.6 and 2.9 times higher than that of DBP in the muscle, adipose tissue and skin

  8. Screening of phthalate esters in 47 branded perfumes.

    Science.gov (United States)

    Al-Saleh, Iman; Elkhatib, Rola

    2016-01-01

    In the last few years, the use of phthalates in perfumes has gained attention because these chemicals are sometimes added intentionally as a solvent and a fixative. Five phthalate esters, dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), and diethyl hexyl phthalate (DEHP), were measured in 47 branded perfumes using headspace solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The results revealed considerable amounts of phthalate in all 47 brands with detection frequencies > limit of quantitation in the following order: DEP (47/47) > DMP (47/47) > BBP (47/47) > DEHP (46/47) > DBP (23/45). Of the 47 brands, 68.1, 72.3, 85.1, 36.2, and 6.7 % had DEP, DMP, BBP, DEHP, and DBP levels, respectively, above their reported threshold limits. Of these phthalates, DEP was found to have the highest mean value (1621.625 ppm) and a maximum of 23,649.247 ppm. The use of DEP in the perfume industry is not restricted because it does not pose any known health risks for humans. DMP had the second highest level detected in the perfumes, with a mean value of 30.202 ppm and a maximum of 405.235 ppm. Although DMP may have some uses in cosmetics, it is not as commonly used as DEP, and again, there are no restrictions on its use. The levels of BBP were also high, with a mean value of 8.446 ppm and a maximum of 186.770 ppm. Although the EU banned the use of BBP in cosmetics, 27 of the tested perfumes had BBP levels above the threshold limit of 0.1 ppm. The mean value of DEHP found in this study was 5.962 ppm, and a maximum was 147.536 ppm. In spite of its prohibition by the EU, 7/28 perfumes manufactured in European countries had DEHP levels above the threshold limit of 1 ppm. The DBP levels were generally low, with a mean value of 0.0305 ppm and a maximum value of 0.594 ppm. The EU banned the use of DBP in cosmetics; however, we found three brands that were above the

  9. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag

    International Nuclear Information System (INIS)

    Pradeep, S.; Benjamin, Sailas

    2012-01-01

    Highlights: ► Three novel phthalate utilizing fungi: A. parasiticus, F. subglutinans and P. funiculosum. ► Fungi utilize DEHP in PVC plastics in situ, in simple mineral salt medium. ► Employing these fungi, a batch process can remediate phthalates in plastics. ► Phthalate-free PVC can be recycled afresh. ► Mineral salt and phthalate remediated into fungal biomass. - Abstract: This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC–MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil – either singly or in consortium – completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (∼0.15–0.35 g/g BB; OD ∼7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue.

  10. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep, S. [Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635 (India); Benjamin, Sailas, E-mail: sailasben@yahoo.co.in [Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635 (India)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Three novel phthalate utilizing fungi: A. parasiticus, F. subglutinans and P. funiculosum. Black-Right-Pointing-Pointer Fungi utilize DEHP in PVC plastics in situ, in simple mineral salt medium. Black-Right-Pointing-Pointer Employing these fungi, a batch process can remediate phthalates in plastics. Black-Right-Pointing-Pointer Phthalate-free PVC can be recycled afresh. Black-Right-Pointing-Pointer Mineral salt and phthalate remediated into fungal biomass. - Abstract: This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 Degree-Sign C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass ({approx}0.15-0.35 g/g BB; OD {approx}7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large

  11. Elevated phthalates' exposure in children with constitutional delay of growth and puberty.

    Science.gov (United States)

    Xie, Changming; Zhao, Yan; Gao, Lianlian; Chen, Jiao; Cai, Depei; Zhang, Yunhui

    2015-05-15

    Phthalates have been proven to be antiandrogenic, which may interfere with the timing of puberty. Children with Constitutional Delay of Growth and Puberty (CDGP) typically display short stature and pubertal delay. This study investigated whether phthalate's exposure was associated with CDGP, and evaluated the potential mediator role of testosterone. In this case-control study, a total of 167 boys, including 57 boys with CDGP (cases) and 110 controls were enrolled. We measured six major phthalate metabolites in urine samples using high-performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). The serum testosterone level was determined by radioimmunoassay. Children in the CDGP group were determined to have significantly elevated urinary phthalates concentration compared with control subjects (total phthalates median: case, 107.00 ng/ml; control, 62.22 ng/ml, p = 0.001). After adjustment for BMI and other confounding factors: mono-n-butyl phthalate (MBP), monoethyl phthalate (MEP) and total phthalate concentrations were significantly negatively associated with serum testosterone level (MBP: β = -45.7, p = 0.017; MEP: β = -31.6, p = 0.022; total phthalates: β = -24.6, p = 0.011); MBP, MEP, mono (2-ethylhexyl) phthalate (MEHP) and total phthalates were significantly associated with CDGP (odds ratio: MBP: 8.30, p = 0.002; MEP: 5.43, p = 0.002; MEHP: 3.83, p = 0.017; total phthalates: 9.09, p = 0.001). Serum testosterone level acted as a mediator of the association between phthalates' exposure and CDGP (p = 0.002) (proportion mediated: 34.4%). In this case-control study, elevated phthalates' level was detected in children with CDGP in Shanghai, China and phthalate level was associated with CDGP, which appeared to be mediated by circulating testosterone level. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Urinary Concentrations of Phthalate Metabolites and Pregnancy Loss Among Women Conceiving with Medically Assisted Reproduction.

    Science.gov (United States)

    Messerlian, Carmen; Wylie, Blair J; Mínguez-Alarcón, Lidia; Williams, Paige L; Ford, Jennifer B; Souter, Irene C; Calafat, Antonia M; Hauser, Russ

    2016-11-01

    Animal studies demonstrate that several phthalates are embryofetotoxic and are associated with increased pregnancy loss and malformations. Results from human studies on phthalates and pregnancy loss are inconsistent. We examined pregnancy loss prospectively in relation to urinary phthalate metabolite concentrations among women undergoing medically assisted reproduction. We used data from 256 women conceiving 303 pregnancies recruited between 2004 and 2012 from the Massachusetts General Hospital Fertility Center. We quantified 11 phthalate metabolite concentrations and calculated the molar sum of four di(2-ethylhexyl) phthalate (DEHP) metabolites (ΣDEHP). We estimated risk ratios (RRs) and 95% confidence intervals for biochemical loss and total pregnancy loss (assisted reproduction.

  13. Single-experiment simultaneous-measurement of elemental mass-attenuation coefficients of hydrogen, carbon and oxygen for 0.123-1.33 MeV gamma rays

    International Nuclear Information System (INIS)

    Teli, M.T.; Nathuram, R.; Mahajan, C.S.

    2000-01-01

    As it is inconvenient to use elements like hydrogen, carbon and oxygen in pure forms for measurement of their gamma mass-attenuation coefficients, the measurements are to be done indirectly, by using compounds of the elements or a mixture of them. We give here a simple method of measuring the total mass-attenuation coefficients μ/ρ of the elements in a compound simultaneously and in a single experiment through the measurements of the μ/ρ values of the concerned compounds and using the mixture rule. The method is applied for the measurement of μ/ρ of hydrogen, carbon and oxygen by using acetone, ethanol and 1-propanol. Our results (for E γ =0.123-1.33 MeV) are seen to be in better agreement with the theoretical values of Hubbell and Seltzer (1995) [Hubbell J.H. and Seltzer S.M. (1995). Tables of X-ray mass attenuation coefficients and mass energy-absorption coefficients 1 keV to 20 MeV for elements Z=1 to 92 and 48 additional substances of dosimetric interest. NISTIR 5632] as compared to the results of El-Kateb and Abdul-Hamid (1991) [El-Kateb, A.H., Abdul-Hamid, A.S., 1991. Photon attenuation coefficient study of some materials containing hydrogen, carbon, and oxygen. Appl. Rad. Isot. 42, 303-307

  14. Thermally-driven hydrogen interaction with single-layer graphene on SiO2/Si substrates

    International Nuclear Information System (INIS)

    Feijo, Tais Orestes; Rolim, Guilherme Koszeniewski; Radtke, Claudio; Soares, Gabriel Vieira

    2016-01-01

    Full text: Graphene is a monolayer of carbon with sp 2 hybridization and hexagonal structure. Since all its area is exposed to the atmosphere, it is important to understand how graphene interacts with elements present in the atmosphere, such as hydrogen, oxygen and water, to control the processes of manufacturing [1]. In addition, some studies show that graphene can allow storage of hydrogen for use in fuel cells, which would contribute to the use of clean energies. This study aims to understand the thermally-driven hydrogen interaction with graphene samples. We used samples of graphene deposited on SiO 2 (285 nm) films on Si and then annealed in controlled atmosphere of deuterium (D 2 , natural abundance of 0.15%) at temperatures between 200 and 1000°C. We also investigated hydrogen desorption from graphene using samples previously treated in deuterium at 600°C and afterwards annealed in nitrogen atmosphere between 200 and 1000°C. After annealings, Nuclear Reaction Analysis (NRA) was employed to quantify deuterium, where we observed a large increase in deuterium incorporation above 400°C, with an constant D incorporation until 1000°C. We also observed that the desorption of deuterium from graphene only occurred above 800°C, although D desorption from silicon oxide samples takes place already at 600°C. Raman spectroscopy analysis was performed after each thermal treatment. Results show that defects in the graphene structure increases for higher treatment temperatures in incorporation and in desorption steps. Characterization using X-Ray Photoelectron Spectroscopy (XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) will also be presented. [1] A. C. Ferrari, et al., Nanoscale 7 (2015). (author)

  15. Urinary phthalate concentrations in mothers and their children in Ireland

    DEFF Research Database (Denmark)

    Cullen, Elizabeth; Evans, David; Griffin, Chris

    2017-01-01

    . This study aimed to determine the extent of phthalate exposure among mothers and their children in both rural and urban areas in Ireland, and to identify factors associated with elevated concentrations. It formed part of the ‘Demonstration of a study to Co-ordinate and Perform Human Biomonitoring...... on a European Scale’ (DEMOCOPHES) pilot biomonitoring study. Methods: the concentration of phthalate metabolites were determined from a convenience sample of 120 mother/child pairs. The median age of the children was 8 years. A questionnaire was used to collect information regarding lifestyle and environmental...... conditions of the children and mothers. Rigorous quality assurance within DEMOCOPHES guaranteed the accuracy and international comparability of results. Results: Phthalate metabolites were detected in all of the samples from both children and mothers. Concentrations were significantly higher in respondents...

  16. Migration of phthalates on culture plates - an important challenge to consider for in vitro studies.

    Science.gov (United States)

    Frohnert Hansen, Juliana; Boas, Malene; Møller Brorson, Marianne; Frederiksen, Hanne; Hartoft-Nielsen, Marie-Louise; Krogh Rasmussen, Åse; Main, Katharina M; Feldt-Rasmussen, Ulla

    2016-01-01

    Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.

  17. Dermal toxicity elicited by phthalates: evaluation of skin absorption, immunohistology, and functional proteomics.

    Science.gov (United States)

    Pan, Tai-Long; Wang, Pei-Wen; Aljuffali, Ibrahim A; Hung, Yi-Yun; Lin, Chwan-Fwu; Fang, Jia-You

    2014-03-01

    The toxicity of phthalates is an important concern in the fields of environmental health and toxicology. Dermal exposure via skin care products, soil, and dust is a main route for phthalate delivery. We had explored the effect of topically-applied phthalates on skin absorption and toxicity. Immunohistology, functional proteomics, and Western blotting were employed as methodologies for validating phthalate toxicity. Among 5 phthalates tested, di(2-ethylhexyl)phthalate (DEHP) showed the highest skin reservoir. Only diethyl phthalate (DEP) and dibutyl phthalate (DBP) could penetrate across skin. Strat-M(®) membrane could be used as permeation barrier for predicting phthalate penetration through skin. The accumulation of DEHP in hair follicles was ∼15nmol/cm(2), which was significantly greater than DBP and DEP. DBP induced apoptosis of keratinocytes and fibroblasts via caspase-3 activation. This result was confirmed by downregulation of 14-3-3 and immunohistology of TUNEL. On the other hand, the HSP60 overexpression and immunostaining of COX-2 suggested inflammatory response induced by DEP and DEHP. The proteomic profiling verified the role of calcium homeostasis on skin inflammation. Some proteins investigated in this study can be sensitive biomarkers for dermal toxicity of phthalates. These included HSPs, 14-3-3, and cytokeratin. This work provided novel platforms for examining phthalate toxicity on skin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Human Elimination of Phthalate Compounds: Blood, Urine, and Sweat (BUS) Study

    Science.gov (United States)

    Genuis, Stephen J.; Beesoon, Sanjay; Lobo, Rebecca A.; Birkholz, Detlef

    2012-01-01

    Background. Individual members of the phthalate family of chemical compounds are components of innumerable everyday consumer products, resulting in a high exposure scenario for some individuals and population groups. Multiple epidemiological studies have demonstrated statistically significant exposure-disease relationships involving phthalates and toxicological studies have shown estrogenic effects in vitro. Data is lacking in the medical literature, however, on effective means to facilitate phthalate excretion. Methods. Blood, urine, and sweat were collected from 20 individuals (10 healthy participants and 10 participants with assorted health problems) and analyzed for parent phthalate compounds as well as phthalate metabolites using high performance liquid chromatography-tandem mass spectrometry. Results. Some parent phthalates as well as their metabolites were excreted into sweat. All patients had MEHP (mono(2-ethylhexyl) phthalate) in their blood, sweat, and urine samples, suggesting widespread phthalate exposure. In several individuals, DEHP (di (2-ethylhexl) phthalate) was found in sweat but not in serum, suggesting the possibility of phthalate retention and bioaccumulation. On average, MEHP concentration in sweat was more than twice as high as urine levels. Conclusions. Induced perspiration may be useful to facilitate elimination of some potentially toxic phthalate compounds including DEHP and MEHP. Sweat analysis may be helpful in establishing the existence of accrued DEHP in the human body. PMID:23213291

  19. Hydrogen sulfide detection based on reflection: from a poison test approach of ancient China to single-cell accurate localization.

    Science.gov (United States)

    Kong, Hao; Ma, Zhuoran; Wang, Song; Gong, Xiaoyun; Zhang, Sichun; Zhang, Xinrong

    2014-08-05

    With the inspiration of an ancient Chinese poison test approach, we report a rapid hydrogen sulfide detection strategy in specific areas of live cells using silver needles with good spatial resolution of 2 × 2 μm(2). Besides the accurate-localization ability, this reflection-based strategy also has attractive merits of convenience and robust response when free pretreatment and short detection time are concerned. The success of endogenous H2S level evaluation in cellular cytoplasm and nuclear of human A549 cells promises the application potential of our strategy in scientific research and medical diagnosis.

  20. Monte Carlo calculation of energy loss of hydrogen and helium ions transmitted under channelling conditions in silicon single crystal

    International Nuclear Information System (INIS)

    El Bounagui, O.; Erramli, H.

    2010-01-01

    In this work, we report on calculations of the electronic channelling energy loss of hydrogen and helium ions along Si and Si axial directions for the low energy range by using the Monte Carlo simulation code. Simulated and experimental data are compared for protons and He ions in the and axis of silicon. A reasonable agreement was found. Computer simulation was also employed to study the angular dependence of energy loss for 0.5, 0.8, 1, and 2 MeV channelled 4 He ions transmitted through a silicon crystal of 3 μm thickness along the axis.

  1. Co-treatment of hydrogen sulfide and methanol in a single-stage biotrickling filter under acidic conditions.

    Science.gov (United States)

    Jin, Yaomin; Veiga, María C; Kennes, Christian

    2007-06-01

    Biofiltration of waste gases is cost-effective and environment-friendly compared to the conventional techniques for treating large flow rates of gas streams with low concentrations of pollutants. Pulp and paper industry off-gases usually contain reduced sulfur compounds, such as hydrogen sulfide and a wide range of volatile organic compounds (VOCs), e.g., methanol. It is desirable to eliminate both of these groups of compounds. Since the co-treatment of inorganic sulfur compounds and VOCs in biotrickling filters is a relatively unexplored area, the simultaneous biotreatment of H2S and methanol as the model VOC was investigated. The results showed that, after adaptation, the elimination capacity of methanol could reach around 236 g m(-3) h(-1) with the simultaneous complete removal (100%) of 12 ppm H2S when the empty bed residence time is 24 s. The pH of the system was around 2. Methanol removal was hardly affected by the presence of hydrogen sulfide, despite the low pH. Conversely, the presence of the VOC in the waste gas reduced the efficiency of H2S biodegradation. The maximal methanol removal decreased somewhat when increasing the gas flow rate. This is the first report on the degradation of methanol at such low pH in a biotrickling filter and on the co-treatment of H2S and VOCs under such conditions.

  2. Hydrogen energy

    International Nuclear Information System (INIS)

    2005-03-01

    This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

  3. Diethyl Phthalate Causes Oxidative Stress: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Heena Prajapati

    2014-03-01

    Full Text Available Background: Phthalates are a group of multifunctional chemicals. Diethyl phthalate (DEP is one of the most frequently used phthalates in solvents and fixatives for numerous industrial products. Method: The present experiment was designed to assess oxidative stress, if any, caused by diethyl phthalate. For this the homogenates of liver and kidney were treated with different concentrations ( 10-40 µg/mL of DEP. 10% liver and kidney homogenates were prepared in phosphate buffered saline and used for estimation of lipid peroxidation.In final step lipid peroxidation and total protein content were analyzed. Results: The result revealed significant and dose - dependent increase in lipid peroxidation, whereas protein content reduced significantly. Maximum increase in LPO and decrease in protein content was observed at 40 µg/mL of DEP concentration. Conclusion: From this study, it can be concluded that different concentrations of DEP leads to dose- dependent significant increase in lipid peroxidation and decrease protein content.So at the different concentration of DEP cause oxidative stress.

  4. Toxic effects of sublethal concentrations of diethyl Phthalate on the ...

    African Journals Online (AJOL)

    An investigation on the effect of Diethyl phthalate (DEP) on the gill of the African catfish Clarias gariepinus was carried out in the laboratory. Seventy-five (75) catfish fingerlings were subjected to continuous exposure to sublethal concentrations of DEP (30, 40, 60 and 80 ìg/L) for a period of four weeks. The gills of the catfish ...

  5. Isolation and Identification of an Antimutagenic Phthalate Derivative ...

    African Journals Online (AJOL)

    from IR and 1H and 13C NMR suggested the presence of phthalate type of compounds. GC-MS analysis .... function group at δ = 167.7 ppm (Figure 3c and. 3d), which is a .... Shahidi F, Miraliakbari H. Omega-3 (n-3) fatty acids in health and ...

  6. Phthalate ester plasticizers in freshwater systems of Venda, South ...

    African Journals Online (AJOL)

    Liquid-liquid extraction, column chromatographic clean-up and capillary gas ... Levels of phthalates in water samples from the rivers and dams ranged from 0.16 mg/ℓ ... with their common use in plastic materials and other industrial chemicals.

  7. Analysis of phthalate esters contamination in drinking water samples ...

    African Journals Online (AJOL)

    The optimum condition method was successfully applied to the analysis of phthalate esters contamination in bottled drinking water samples. The concentration of DMP, DEP and DBP in drinking water samples were below allowable levels, while the DEHP concentration in three samples was found to be greater than the ...

  8. Ligninolytic system of Phanerochaete chrysosporium: inhibition by o-phthalate

    Energy Technology Data Exchange (ETDEWEB)

    Fenn, P.; Kirk, T.K.

    1979-01-01

    The degradation rate of (synthetic/sup 14/C)-lignin to /sup 14/CO/sub 2/ by Phanerochaete chrysosporium in cultures buffered with 0.01 M 2,2-dimethylsuccinate (DMS) was twice that in 0.01 M o-phthalate-buffered cultures. This difference could be totally accounted for by o-phthalate inhibition of the activity of the ligninolytic system. /sup 14/CO/sub 2/ production from ring-, sidechain-, and methoyxl-labled lignins was inhibited, the degree of inhibition being dependent on o-phthalate concentration. Oxidations of /sup 14/C-glucose, /sup 14/C-acetovanillone, and /sup 14/C-apocynol were not inhibited; thus o-phthalate is not a general inhibitor, and might inhibit activities involved in attach of the lignin polymer. DMS is a suitable buffer for the ligninolytic system. Degradation rates of ring-labeled lignin to /sup 14/CO/sub 2/ of 10 to 15% in 24 h were obtained consistently over the pH range 3.6 to 4.5, with an optimum near pH 4.0.

  9. Success and failure with phthalate buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Bocek, P; Gebauer, P; Beckers, J L

    2001-04-01

    Phthalate buffers are currently used in capillary electrophoresis as robust electrolyte systems for indirect detection. This contribution demonstrates that these buffers show regularly not only successful regions of mobilities of analytes (sample window) but also regions of failure where the migration of analytes is strongly deteriorated due to the presence of a system zone. System zones in phthalate buffers may be easily detected by UV detection and manifest themselves as peaks or dips. Peak shape diagrams are advantageously used for the prediction of the migration behavior of system zones in phthalate background electrolyte (BGE) systems at various pH. It is shown that the mobility of the system zone varies strongly with pH, is practically zero at pH values below 4 and above 7, and shows a maximum at pH 5. Thus, the system peak may coincide either with the peaks of various analytes or with the electroosmotic flow (EOF) peak. Experiments are given showing the effects of such coincidences as, e.g., zigzag detection patterns, double EOF peaks, and/or unusually broad peaks/dips. The message of this contribution is to show how to understand the electrophoretic properties of phthalate BGEs that, regardless of possible failure regions, may be successfully used in the analytical practice of capillary zone electrophoresis (CZE).

  10. Toxicological investigation of di(cyclohexyl)phthalate in rats

    NARCIS (Netherlands)

    van den Ham WA; Jansen EHJM; de Fluiter P; van Leeuwen FXR

    1992-01-01

    In a study in which male rats have been exposed to 0, 20, 60, 200, 600 and 2000 mg di(cyclohexyl)phthalate (DCHP)/kg diet for 2 weeks, body weight and liver weight and a number of enzym parameters which are related with peroxisome proliferation palmitoyl coenzyme-A oxidase (PCO), enoyl coenzyme-A

  11. Distribution of phthalate esters in underground water from power ...

    African Journals Online (AJOL)

    This study investigates the distribution of phthalateacid esters (PAEs) in groundwater from some power stations in Delta State. Groundwater samples were collected from eight power transmission and distribution stations. Concentrations (μg/L) of six phthalate acid esters compounds in the groundwater ranged from ...

  12. Increased Urinary Phthalate Levels in Women with Uterine Leiomyoma: A Case-Control Study.

    Science.gov (United States)

    Kim, Young Ah; Kho, Younglim; Chun, Kyoung Chul; Koh, Jae Whoan; Park, Jeong Woo; Bunderson-Schelvan, Melisa; Cho, Yoon Hee

    2016-12-15

    We assessed the urinary concentration of 16 phthalate metabolites in 57 women with and without uterine leiomyoma ( n = 30 and 27; respectively) to determine the association between phthalate exposure and uterine leiomyoma. To evaluate exposure to di-(2-ethylhexyl) phthalate (DEHP); we calculated the molar sum of DEHP metabolites; ∑3-DEHP (combining mono-(2-ethylhexyl) phthalate (MEHP); mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP); and mono-(2-ethyl-5-oxohexyl) phthalate); ∑4-DEHP (∑3-DEHP plus mono-(2-ethyl-5-carboxypentyl) phthalate); and ∑5-DEHP (∑4-DEHP plus mono (2-(carboxylmethyl)hexyl) phthalate (2cx-MMHP)). The log transformed urinary levels of MEHP; MEHHP; 2cx-MMHP; ∑3-DEHP; ∑4-DEHP; and ∑5-DEHP in the leiomyoma group were significantly higher than those of controls. When we adjusted for age; waist circumference; and parity using multiple logistic regression analyses; we found log ∑3-DEHP (OR = 10.82; 95% CI = 1.25; 93.46) and ∑4-DEHP (OR = 8.78; 95% CI = 1.03; 75.29) were significantly associated with uterine leiomyoma. Our findings suggest an association between phthalate exposure and uterine leiomyoma. However; larger studies are needed to investigate potential interactions between phthalate exposure and uterine leiomyoma.

  13. AC dielectrophoresis alignment of single-walled carbon nano tubes (SWNTS) and palladium nano wires for hydrogen gas sensor

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Nur Ubaidah Saidin; Ying, K.K.; KKhuan, N.I.; Mohammad Hafizuddin Jumali

    2013-01-01

    Full-text: Using AC electric field, nano wires or nano tubes can be aligned, chained or accelerated in a direction parallel to the applied field, oriented or concentrated onto designated locations as well as dispersed in controlled manner under high efficiencies. In this work, systematic study on the alignment of nano wires/ nano tubes across the 3 μm-gaps between pairs of micro fabricated gold electrodes was carried out using AC dielectrophoresis technique. Densities and alignment of the nano wires/ nano tubes across the gaps of the electrodes were controlled by the applied AC field strengths and frequencies on the electrodes. Good alignments of SWNTs and Pd nano wires were achieved at an applied frequency of 5 MHz and a field strength as high as 25 V pp for Pd nano wires compared to only 2 V pp for SWNTs. The aligned nano wires/ nano tubes will be functioned as sensor elements for hydrogen gas sensing. (author)

  14. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  15. Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia

    International Nuclear Information System (INIS)

    Cheng, Zhang; Li, Han-Han; Wang, Hong-sheng; Zhu, Xue-Mei; Sthiannopkao, Suthipong; Kim, Kyoung-Woong; Yasin, Mohamed Salleh Mohamed; Hashim, Jamal Hisham; Wong, Ming-Hung

    2016-01-01

    Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of human to phthalates are limited. In this study, to assess the daily intakes of phthalate esters and the possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑phthalate ester concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 0.05 to 2.34 (median 0.88) μg g −1 , 0.19–1.65 (median 0.86) μg g −1 and 0.24–3.05 (median 0.59) μg g −1 wet weight (ww), respectively. Di-2-Ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP) were the predominant compounds among all foodstuffs. The estimated daily intake (EDI) of phthalate esters for the general population in Kampong Cham, Kratie and Kandal was 34.3, 35.6 and 35.8 μg kg −1 bw d −1 , respectively. The dietary daily intake of DEHP, benzylbutyl phthalate (BBP) and di-n-butyl phthalate (DBP) in Kampong Cham, Kratie and Kandal were below the tolerable daily intakes (TDI) imposed by the European Food Safety Authority (EFSA) and reference doses (RfD) imposed by The United States Environmental Protection Agency (USEPA). Rice contributed the greatest quantity of DEHP to the daily intake in Cambodia so may deserve further exploration. To our knowledge, this is the first study to investigate the occurrence and the daily intakes of phthalate esters in Cambodia. - Highlights: • Phthalate esters concentration in daily foodstuffs collected from Cambodia. • Investigate the bioaccessbility of phthalate esters via the foodstuffs consumption. • Health risk evaluation of dietary exposure to phthalate esters.

  16. Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Zhang; Li, Han-Han [College of Environment, Sichuan Agricultural University, Chengdu 611130 (China); Wang, Hong-sheng [Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, No.132 Waihuandong Road, University Town, Guangzhou 510006 (China); Zhu, Xue-Mei [College of Environment, Sichuan Agricultural University, Chengdu 611130 (China); Sthiannopkao, Suthipong [Department of Environmental and Occupational Health, National Cheng Kung University, Tainan City, Taiwan (China); Kim, Kyoung-Woong [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Yasin, Mohamed Salleh Mohamed; Hashim, Jamal Hisham [United Nations University-International Institute for Global Health, Kuala Lumpur (Malaysia); Wong, Ming-Hung, E-mail: minghwong@ied.edu.hk [Consortium on Health, Environment, Education and Research (CHEER), and Department of Science and Environmental Studies, Hong Kong Institute of Education, Tai Po, Hong Kong (China); School of Environment, Jinan University, Guangzhou (China)

    2016-10-15

    Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of human to phthalates are limited. In this study, to assess the daily intakes of phthalate esters and the possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑phthalate ester concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 0.05 to 2.34 (median 0.88) μg g{sup −1}, 0.19–1.65 (median 0.86) μg g{sup −1} and 0.24–3.05 (median 0.59) μg g{sup −1} wet weight (ww), respectively. Di-2-Ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP) were the predominant compounds among all foodstuffs. The estimated daily intake (EDI) of phthalate esters for the general population in Kampong Cham, Kratie and Kandal was 34.3, 35.6 and 35.8 μg kg{sup −1} bw d{sup −1}, respectively. The dietary daily intake of DEHP, benzylbutyl phthalate (BBP) and di-n-butyl phthalate (DBP) in Kampong Cham, Kratie and Kandal were below the tolerable daily intakes (TDI) imposed by the European Food Safety Authority (EFSA) and reference doses (RfD) imposed by The United States Environmental Protection Agency (USEPA). Rice contributed the greatest quantity of DEHP to the daily intake in Cambodia so may deserve further exploration. To our knowledge, this is the first study to investigate the occurrence and the daily intakes of phthalate esters in Cambodia. - Highlights: • Phthalate esters concentration in daily foodstuffs collected from Cambodia. • Investigate the bioaccessbility of phthalate esters via the foodstuffs consumption. • Health risk evaluation of dietary exposure to phthalate esters.

  17. Biodegradation of dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate by Rhodococcus sp. L4 isolated from activated sludge.

    Science.gov (United States)

    Lu, Yi; Tang, Fei; Wang, Ying; Zhao, Jinhui; Zeng, Xin; Luo, Qifang; Wang, Lin

    2009-09-15

    In this study, an aerobic bacterial strain capable of utilizing dimethyl phthalate (DMP), diethyl phthalate (DEP) and di-n-butyl phthalate (DBP) as sole carbon source and energy was isolated from activated sludge collected from a dyeing plant. According to its morphology, physiochemical characteristics and 16S rDNA sequence, the strain was identified as Rhodococcus ruber. The biodegradation batch tests of DMP, DEP and DBP by the Rhodococcus sp. L4 showed the optimal pH value, temperature and substrate concentration: pH 7.0-8.0, 30-37 degrees C and PAEs concentration Kinetics of degradation have also been performed at different initial concentrations. The results show that the degradation can be described with exponential model. The half-life of degradation was about 1.30 days when the concentration of PAEs mixture was lower than 300 mg/L. PAEs contaminated water samples (300 mg/L) with non-emulsification and completed emulsification were prepared to investigate the effect on PAEs degradation rate. Little difference between the above two sample preparations was observed in terms of ultimate degradation rate. Rhodococcus sp. L4 can also grow on phenol, sodium benzoate or naphthalene solution as sole carbon source and energy which suggests its ability in resisting environmental toxicants. This work provides some new evidence for the possibility of applying Rhodococcus for contaminated water remediation in the area of industry.

  18. Phthalate release in leachate from municipal landfills of central Poland.

    Science.gov (United States)

    Wowkonowicz, Paweł; Kijeńska, Marta

    2017-01-01

    Phthalate diesters (PAEs) are used as plasticizer additives to polymer chains to make the material more flexible and malleable. PAEs are bonded physically, not chemically, to the polymeric matrix and can migrate to and leach from the product surface, posing a serious danger to the environment and human health. There have been a number of studies on PAE concentrations in landfill leachate conducted in the EU and around the world, though few in Poland. In the present study, the leachate of five municipal landfills was analyzed for the presence of PAEs. Raw leachate was sampled four times over the period of one year in 2015/16. It was the first large study on this subject in Poland. PAEs were detected in the leachate samples on all of the landfills, thereby indicating that PAEs are ubiquitous environmental contaminants. The following PAEs were detected in at least one sample: Di(2-ethylhexyl) phthalate (DEHP), Diethyl phthalate (DEP), Dimethyl phthalate (DMP), Di-n-butyl phthalate (DBP), Di-isobutylphthalate (DIBP). Out of all ten PAEs, DEHP was the most predominant, with concentrations up to 73.9 μg/L. DEHP was present in 65% of analyzed samples (in 100% of samples in spring, 80% in winter, and 40% in summer and autumn). In only 25% of all samples DEHP was below the acceptable UE limit for surface water (1.3 μg/L), while 75% was from 1.7 to 56 times higher than that value. On the two largest landfills DEHP concentrations were observed during samples from all four seasons, including on a landfill which has been remediated and closed for the last 5 years.

  19. Systemic uptake of diethyl phthalate, dibutyl phthalate, and butyl paraben following whole-body topical application and reproductive and thyroid hormone levels in humans

    DEFF Research Database (Denmark)

    Janjua, Nadeem Rezaq; Mortensen, Gerda Krogh; Andersson, Anna-Maria

    2007-01-01

    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...

  20. The association between phthalate exposure and atopic dermatitis with a discussion of phthalate induced secretion of interleukin-1β and thymic stromal lymphopoietin

    DEFF Research Database (Denmark)

    Overgaard, Line E K; Bonefeld, Charlotte M.; Frederiksen, Hanne

    2016-01-01

    Phthalate diesters are widely used as emollients in plastic and cosmetics as well as in food packaging and perfumes, potentially leading to prolonged and repeated dermal, oral and airborne exposure. We here review published articles that have evaluated the putative role of phthalate diesters...

  1. Emission of phthalates and phthalate alternatives from vinyl flooring and crib mattress covers: the influence of temperature.

    Science.gov (United States)

    Liang, Yirui; Xu, Ying

    2014-12-16

    Emissions of phthalates and phthalate alternatives from vinyl flooring and crib mattress covers were measured in a specially designed chamber. The gas-phase concentrations versus time were measured at four different temperatures, that is, 25, 36, 45, and 55 °C. The key parameter that controls the emissions (y0, gas-phase concentration in equilibrium with the material phase) was determined, and the emissions were found to increase significantly with increasing temperature. Both the material-phase concentration (C0) and the chemical vapor pressure (Vp) were found to have great influence on the value of y0. The measured ratios of C0 to y0 were exponentially proportional to the reciprocal of temperature, in agreement with the van't Hoff equation. A emission model was validated at different temperatures, with excellent agreement between model calculations and chamber observations. In residential homes, an increase in the temperature from 25 to 35 °C can elevate the gas-phase concentration of phthalates by more than a factor of 10, but the total airborne concentration may not increase that much for less volatile compounds. In infant sleep microenvironments, an increase in the temperature of mattress can cause a significant increase in emission of phthalates from the mattress cover and make the concentration in the infant's breathing zone about four times higher than that in the bulk room air, resulting in potentially high exposure.

  2. 75 FR 31426 - Notice of Meeting of Chronic Hazard Advisory Panel on Phthalates and Phthalate Substitutes and...

    Science.gov (United States)

    2010-06-03

    ... . SUPPLEMENTARY INFORMATION: The Commission has previously investigated potential risks posed to children from... consumer products, food, cosmetics, medical devices, and the environment. Certain phthalates have been...) Examine all of the potential health effects (including endocrine disrupting effects) of the full range of...

  3. Blood burden of di(2-ethylhexyl) phthalate and its primary metabolite mono(2-ethylhexyl) phthalate in pregnant and nonpregnant rats and marmosets

    International Nuclear Information System (INIS)

    Kessler, Winfried; Numtip, Wanwiwa; Grote, Konstanze; Csanady, Gyoergy A.; Chahoud, Ibrahim; Filser, Johannes G.

    2004-01-01

    A comparison of the dose-dependent blood burden of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP) in pregnant and nonpregnant rats and marmosets is presented. Sprague-Dawley rats and marmosets were treated orally with 30 or 500 mg DEHP/kg per day, nonpregnant animals on 7 (rats) and 29 (marmosets) consecutive days, pregnant animals on gestation days 14-19 (rats) and 96-124 (marmosets). In addition, rats received a single dose of 1000 mg DEHP/kg. Blood was collected up to 48 h after dosing. Concentrations of DEHP and MEHP in blood were determined by GC/MS. In rats, normalized areas under the concentration-time curves (AUCs) of DEHP were two orders of magnitude smaller than the normalized AUCs of the first metabolite MEHP. Metabolism of MEHP was saturable. Repeated DEHP treatment and pregnancy had only little influence on the normalized AUC of MEHP. In marmosets, most of MEHP concentration-time courses oscillated. Normalized AUCs of DEHP were at least one order of magnitude smaller than those of MEHP. In pregnant marmosets, normalized AUCs of MEHP were similar to those in nonpregnant animals with the exception that at 500 mg DEHP/kg per day, the normalized AUCs determined on gestation days 103, 117, and 124 were distinctly smaller. The maximum concentrations of MEHP in blood of marmosets were up to 7.5 times and the normalized AUCs up to 16 times lower than in rats receiving the same daily oral DEHP dose per kilogram of body weight. From this toxicokinetic comparison, DEHP can be expected to be several times less effective in the offspring of marmosets than in that of rats if the blood burden by MEHP in dams can be regarded as a dose surrogate for the MEHP burden in their fetuses

  4. Phthalates in PM2.5 airborne particles in the Moravian-Silesian Region, Czech Republic

    Directory of Open Access Journals (Sweden)

    Jana Růžičková

    2016-03-01

    Full Text Available Industrial area of the Moravian-Silesian Region (the Czech Republic is highly polluted by air contaminants, especially emissions of particulate matter. Samples of PM2.5 particles were analysed by pyrolysis gas chromatography with mass spectrometric detection. Concentrations of phthalates were determined for the winter season, transitional period and the summer season. The relative concentrations of phthalates in PM2.5 particles have the same proportion in both heating and non-heating season: di(2ethylexyl phthalate > di-n-butyl phthalate > diisononyl phthalate > diethyl phthalate. The most common increase in concentration in the winter season is from 5 to 10 times higher; the maximum of average concentration was 44 times higher than in the non-heating season.

  5. Phthalate metabolites in Norwegian mothers and children: Levels, diurnal variation and use of personal care products.

    Science.gov (United States)

    Sakhi, Amrit Kaur; Sabaredzovic, Azemira; Cequier, Enrique; Thomsen, Cathrine

    2017-12-01

    Exposure to phthalates has been associated with reproductive and developmental toxicity. Data on levels of these compounds in the Norwegian population is limited. In this study, urine samples were collected from 48 mothers and their children in two counties in Norway. Eleven different phthalate metabolites originating from six commonly used phthalates in consumer products were determined. Concentrations of phthalate metabolites were significantly higher in children compared to mothers except for mono-ethyl phthalate (MEP). The mothers provided several urine samples during 24hours (h) and diurnal variation showed that the concentrations in the morning urine samples (24-8h) were significantly higher than at other time-periods for most of the phthalate metabolites. Intraclass correlation coefficients (ICCs) for 24-hour time-period were in the range of 0.49-0.81. These moderate to high ICCs indicate that one spot urine sample can be used to estimate the exposure to phthalates. Since a significant effect of time of day was observed, it is still advisable to standardize the collection time point to reduce the variation. For the mothers, the use of personal care products (PCPs) were less associated with morning urine samples than early day (8-12h) and evening (16-24h) urine samples. The use of perfume and hair products were positively associated with the urinary concentrations of low molecular weight phthalates. Use of shower soap and shampoo were positively associated with urinary concentration of di(2-ethylhexyl) phthalate (DEHP) metabolites. For children, face cream use was positively associated with phthalate metabolites in the morning samples, and hand soap use was negatively associated with concentration of urinary DEHP metabolites in afternoon/evening samples. Since different PCPs were associated with the urinary phthalate metabolites in different time-periods during a day, more than one spot urine sample might be required to study associations between urinary

  6. Early-Life Phthalate Exposure and Adiposity at 8 Years of Age.

    Science.gov (United States)

    Shoaff, Jessica; Papandonatos, George D; Calafat, Antonia M; Ye, Xiaoyun; Chen, Aimin; Lanphear, Bruce P; Yolton, Kimberly; Braun, Joseph M

    2017-09-11

    Early-life phthalate exposure may influence child adiposity, but prior studies have not determined if there are periods of enhanced vulnerability to phthalates. To examine the relationship between child adiposity at 8 y of age and repeated urinary biomarkers of phthalate exposure from gestation through childhood to determine if there are distinct periods of vulnerability. In 219 mother-child pairs from Cincinnati, Ohio, we quantified nine urinary phthalate metabolites up to two times prenatally and six times from 1-8 y of age. We measured child body mass index (BMI), waist circumference, and percent body fat at 8 y of age. To identify periods of vulnerability, we used two statistical methods to estimate phthalate-adiposity associations at each visit, test differences in phthalate-adiposity associations across visits, and model trajectories of phthalate concentrations for children at different levels of adiposity. Prenatal phthalate concentrations were not associated with excess child adiposity. Monobenzyl phthalate (MBzP) concentrations during pregnancy and childhood were inversely associated with adiposity. The associations of di(2-ethylhexyl) phthalate (∑DEHP) metabolites and monoethyl phthalate (MEP) with child adiposity depended on the timing of exposure. A 10-fold increase in ∑DEHP at 1 and 5 y was associated with a 2.7% decrease [95% confidence interval (CI): -4.8, -0.5] and 2.9% increase (95% CI: 0.3, 5.5) in body fat, respectively. MEP concentrations at 5 and 8 y of age were associated with higher child adiposity, but earlier childhood concentrations were not. In this cohort, we did not find evidence of an obesogenic effect of prenatal phthalate exposure. Positive associations between postnatal MEP and ∑DEHP concentrations depended on the timing of exposure. https://doi.org/10.1289/EHP1022.

  7. Semen phthalate metabolites, semen quality parameters and serum reproductive hormones: A cross-sectional study in China.

    Science.gov (United States)

    Wang, Yi-Xin; Zeng, Qiang; Sun, Yang; Yang, Pan; Wang, Peng; Li, Jin; Huang, Zhen; You, Ling; Huang, Yue-Hui; Wang, Cheng; Li, Yu-Feng; Lu, Wen-Qing

    2016-04-01

    Exposure to phthalates has been found to have adverse effects on male reproductive function in animals. However, the findings from human studies are inconsistent. Here we examined the associations of phthalate exposure with semen quality and reproductive hormones in a Chinese population using phthalate metabolite concentrations measured in semen as biomarkers. Semen (n = 687) and blood samples (n = 342) were collected from the male partners of sub-fertile couples who presented to the Reproductive Center of Tongji Hospital in Wuhan, China. Semen quality parameters and serum reproductive hormone levels were determined. Semen concentrations of 8 phthalate metabolites were assessed using high-performance liquid chromatography and tandem mass spectrometry. Associations of the semen phthalate metabolites with semen quality parameters and serum reproductive hormones were assessed using confounder-adjusted linear and logistic regression models. Semen phthalate metabolites were significantly associated with decreases in semen volume [mono-n-butyl phthalate (MBP), mono-(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP)], sperm curvilinear velocity [monobenzyl phthalate (MBzP), MEHP, the percentage of di-(2-ethylhexyl)-phthalate metabolites excreted as MEHP (%MEHP)], and straight-line velocity (MBzP, MEHP, %MEHP), and also associated with an increased percentage of abnormal heads and tails (MBzP) (all p for trend hormones. Our findings suggest that environmental exposure to phthalates may impair human semen quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. The removal of dimethyl phthalate (DMP) from contaminated water by advanced oxidation processes in the presence of methanol

    Energy Technology Data Exchange (ETDEWEB)

    Al-Tawabini, B.S. [Research Inst., King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2003-07-01

    A bench-scale laboratory study was conducted to investigate the effect of alcohol (i.e. methanol) presence on the removal efficiency of phthalates from water using Fenton's reagent and UV/H{sub 2}O{sub 2} process. Dimethyl phthalate (DMP) was selected as a target compound. In one batch of experiments, only DMP was spiked into pure water, while in the other batch, DMP was initially dissolved in methanol prior to spiking into water samples. A UV lamp of 100 m Watt emitting at a wavelength of approximately 254 nm was used to provide the radiation. Temperature and pH conditions were kept constant at 25 C and 3, respectively. The results showed that Fenton's reagent was effective in reducing the concentration of DMP in water in the absence of the methanol. More than 90% of DMP was removed within 45 minutes at hydrogen peroxide (H{sub 2}O{sub 2}) and ferrous ion (Fe{sup 2+}) concentrations of 1.0 and 0.4 mM respectively. However, Fenton's reagent failed to do so in the presence of methanol. On the other hand, results showed that UV/H{sub 2}O{sub 2} system was effective in removing DMP from both pure, as well as methanol-spiked water. The results clearly indicated that UV radiation plays a fundamental role in the degradation of the target compound. (orig.)

  9. Technique for rapid detection of phthalates in water and beverages

    KAUST Repository

    Zia, Asif I.

    2013-05-01

    The teratogenic and carcinogenic effects of phthalate esters on living beings are proven in toxicology studies. These ubiquitous food and environmental pollutants pose a great danger to the human race due to their extraordinary use as a plasticizer in the consumer product industry. Contemporary detection techniques used for phthalates require a high level of skills, expensive equipment and longer analysis time than the presented technique. Presented research work introduces a real time non-invasive detection technique using a new type of silicon substrate based planar interdigital (ID) sensor fabricated on basis of thin film micro-electromechanical system (MEMS) semiconductor device fabrication technology. Electrochemical impedance spectroscopy (EIS) was used in conjunction with the fabricated sensor to detect phthalates in deionized water. Various concentrations of di(2-ethylhexyl) phthalate (DEHP) as low as 2 ppb to a higher level of 2 ppm in deionized water were detected distinctively using new planar ID sensor based EIS sensing system. Dip testing method was used to obtain the conductance and dielectric properties of the bulk samples. Parylene C polymer coating was used as a passivation layer on the surface of the fabricated sensor to reduce the influence of Faradaic currents. In addition, inherent dielectric properties of the coating enhanced the sensitivity of the capacitive type sensor. Electrochemical spectrum analysis algorithm was used to model experimentally observed impedance spectrum to deduce constant phase element (CPE) equivalent circuit to analyse the kinetic processes taking place inside the electrochemical cell. Curve fitting technique was used to extract the values of the circuit components and explain experimental results on theoretical grounds. The sensor performance was tested by adding DEHP to an energy drink at concentrations above and below the minimal risk level (MRL) limit set by the ATSDR (Agency for Toxic Substances & Disease Registry

  10. Recycling of plastic waste: Presence of phthalates in plastics from households and industry

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

    2016-01-01

    recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...... product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications...

  11. Occupational exposure to phthalates in relation to gender, consumer practices and body composition.

    Science.gov (United States)

    Petrovičová, Ida; Kolena, Branislav; Šidlovská, Miroslava; Pilka, Tomáš; Wimmerová, Soňa; Trnovec, Tomáš

    2016-12-01

    The aim of our work was to find associations between urinary phthalate metabolite concentrations and occupation, consumer practices and body composition. We divided our cohort (n = 129) into occupationally exposed subjects, community service workers (group A; n = 45) and workers from plastic industry (group B; n = 35) and group of general population (control group C, n = 49). To estimate levels of five phthalate metabolites, we used high-performance liquid chromatography and tandem mass spectrometry analysis. We found in plastic industry workers compared to community service workers and subjects of the control group significantly higher urinary concentration mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), mono (2-etylhexyl) phthalate (MEHP), sum di-(2-ethyl-5-oxohexyl) phthalate (DEHP), mono-iso-butyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP). We identified by multivariate analysis of covariance inverse relationship between MEHP and body parameters as waist-to-height ratio, body mass index, waist-to-hip ratio, hip circumference and waist circumference among females, whereas in males, no significant association was found. Results of our study show, despite of variability in terms of occupational exposure to phthalates, that plastic manufactory represents a higher occupational risk in comparison with waste management. The differences in anthropometric parameters between the two occupationally exposed groups and the general population are suggesting a detrimental effect of occupational exposure on body weight homeostasis.

  12. Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans

    DEFF Research Database (Denmark)

    Janjua, Nadeem Rezaq; Frederiksen, Hanne; Skakkebaek, Niels E

    2008-01-01

    Diethyl phthalate (DEP), dibutyl phthalate (DBP) and butyl paraben (BP) are man-made chemicals used in personal care products, such as lotions and creams. Exposure to these chemicals causes a variety of adverse reproductive outcomes in animal studies. Humans can be exposed to these chemicals...... were given a whole body topical application of basic cream 2 mg/cm(2) (control week) and then a cream containing 2% (w/w) of DEP, DBP and BP each (treatment week) daily. Twenty-four-hour urine samples were collected. Urinary total, and unconjugated BP, monoethyl phthalate (MEP) and monobutyl phthalate...

  13. Urinary Phthalate Metabolites in American Alligators (Alligator mississippiensis) from Selected Florida Wetlands.

    Science.gov (United States)

    Brock, John W; Bell, Jane Margaret; Guillette, Louis J

    2016-07-01

    Phthalates have been shown to cause endocrine disruption in laboratory animals and are associated with altered development of the reproductive system in humans. Further, human have significant exposure to phthalates. However, little is known concerning the exposure of wildlife to phthalates. We report urinary phthalate metabolite concentrations from fifty juvenile alligators from three Florida lakes and a site in the Everglades. Urinary phthalate monoester concentrations varied widely among alligators from the different sites but also among alligators from the same site. Mono-2-ethylhexy phthalate and monobutyl phthalate were found in most samples of alligator urine with maximums of 35,700 ng/mL and 193 ng/mL, respectively. Monobenzyl phthalate was found in 5 alligators with a maximum of 66.7 ng/mL. Other monoesters were found in only one or two alligator urine samples. The wide variation within and among sites, in addition to the high levels of mEHP, mBP and mBzP, is consistent with exposure arising from the intermittent spraying of herbicide formulations to control invasive aquatic plants in Florida freshwater sites. Phthalate diesters are used as adjuvants in many of these formulations.

  14. Phthalate metabolites in the European eel (Anguilla anguilla) from Mediterranean coastal lagoons.

    Science.gov (United States)

    Fourgous, C; Chevreuil, M; Alliot, F; Amilhat, E; Faliex, E; Paris-Palacios, S; Teil, M J; Goutte, A

    2016-11-01

    The levels and fate of phthalate metabolites have been poorly evaluated in fish, despite their potential ecotoxicological impacts. The present study aims to characterize the levels of phthalate metabolites in muscle tissue of yellow eels (Anguilla anguilla) from two coastal Mediterranean lagoons, during three sampling periods. Nine phthalate metabolites were detected in >70% of the samples. Slightly higher levels of phthalate metabolites were detected in March and June compared to October, suggesting possible seasonal variations in environmental release and/or phthalate metabolization process by eels. The large sample size (N=117) made it possible to explore correlations between phthalate metabolites' levels and individual parameters, such as body length, age, body condition and hepatic histo-pathologies. Body length and estimated age poorly correlated with phthalate metabolites, suggesting that eels did not accumulate phthalates during growth, contrary to persistent compounds. Eels presented different grades of hepatic fibrosis and lipidosis. A negative correlation was found between the severity of these pathologies in the liver and the sum of phthalate metabolites levels, supporting the hypothesis that eels with damaged liver are less able to metabolize xenobiotics. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Human biomonitoring of phthalate exposure in Austrian children and adults and cumulative risk assessment.

    Science.gov (United States)

    Hartmann, Christina; Uhl, Maria; Weiss, Stefan; Koch, Holger M; Scharf, Sigrid; König, Jürgen

    2015-07-01

    Phthalates are a class of chemicals widely used as plasticisers in a multitude of common consumer products. Through contact with such products, people are regularly exposed to phthalates, which are suspected to contribute to adverse health effects, particularly in the reproductive system. In the present study, 14 urinary phthalate metabolites of 10 parent phthalates were analysed by HPLC-MS/MS among the Austrian population aged 6-15 and 18-81 years in order to assess phthalate exposure. In the total study population, ranges of urinary phthalate metabolite concentrations were n.d.-2,105 μg/l (median 25 μg/l) for monoethyl phthalate (MEP), n.d.-88 μg/l (10 μg/l) for mono-n-butyl phthalate (MnBP), n.d.-248 μg/l (28 μg/l) for mono-isobutyl phthalate (MiBP), n.d.-57 μg/l (1.8 μg/l) for mono-benzyl phthalate (MBzP), n.d.-20 μg/l (n.d.) for mono-(2-ethylhexyl) phthalate (MEHP), n.d.-80 μg/l (2.6 μg/l) for mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), n.d.-57 μg/l (1.9 μg/l) for mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), n.d.-219 μg/l (11 μg/l) for mono-(5-carboxy-2-ethylpentyl) phthalate (5cx-MEPP), n.d.-188 μg/l (1.6 μg/l) for 3-carboxy-mono-proply phthalate (3 cx-MPP), n.d.-5.5 μg/l (n.d.) for mono-cyclohexyl phthalate (MCHP), n.d.-4.5 μg/l (n.d.) for mono-n-pentyl phthalate (MnPeP), n.d.-3.4 μg/l (n.d.) for mono-n-octyl phthalate (MnOP), n.d.-13 μg/l (n.d.) for mono-isononyl phthalate (MiNP), and n.d.-1.1 μg/l (n.d.) for mono-isodecyl phthalate (MiDP). Generally, children exhibited higher levels of exposure to the majority of investigated phthalates, except to MEP, which was found in higher concentrations in adults and senior citizens at a maximum concentration of 2,105 μg/l. Individual daily intakes were estimated based on urinary creatinine and urinary volume excretion and were then compared to acceptable exposure levels, leading to the identification of exceedances of mainly the Tolerable Daily Intakes (TDI), especially among

  16. DI(N-BUTYL) PHTHALATE AND DIETHYLHEXYL PHTHALATE IN COMBINATION ALTER SEXUAL DIFFERENTIATION IN A CUMULATIVE MANNER AS A RESULT OF DEPRESSED FETAL TESTOSTERONE PRODUCTION AND INSL3 GENE EXPRESSION IN MALE RATS

    Science.gov (United States)

    Plasticizers di(n-butyl) phthalate (DBP) and diehtylhexyl phthalate (DEHP) have similar modes of action: in utero exposure reduces testosterone (T) production in fetal male rats, inhibits reproductive tract differentiation, and induces reproductive organ malformations. In utero e...

  17. Phthalates Are Metabolised by Primary Thyroid Cell Cultures but Have Limited Influence on Selected Thyroid Cell Functions In Vitro

    DEFF Research Database (Denmark)

    Hansen, Juliana Frohnert; Brorson, Marianne Møller; Boas, Malene

    2016-01-01

    Phthalates are plasticisers added to a wide variety of products, resulting in measurable exposure of humans. They are suspected to disrupt the thyroid axis as epidemiological studies suggest an influence on the peripheral thyroid hormone concentration. The mechanism is still unknown as only few...... in vitro studies within this area exist. The aim of the present study was to investigate the influence of three phthalate diesters (di-ethyl phthalate, di-n-butyl phthalate (DnBP), di-(2-ethylhexyl) phthalate (DEHP)) and two monoesters (mono-n-butyl phthalate and mono-(2-ethylhexyl) phthalate (MEHP......)) on the differentiated function of primary human thyroid cell cultures. Also, the kinetics of phthalate metabolism were investigated. DEHP and its monoester, MEHP, both had an inhibitory influence on 3'-5'-cyclic adenosine monophosphate secretion from the cells, and MEHP also on thyroglobulin (Tg) secretion from...

  18. Human breast milk contamination with phthalates and alterations of endogenous reproductive hormones in infants three months of age

    DEFF Research Database (Denmark)

    Main, Katharina M; Mortensen, Gerda Krog; Kaleva, Marko M

    2006-01-01

    Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis....

  19. Phthalate exposure through different pathways and allergic sensitization in preschool children with asthma, allergic rhinoconjunctivitis and atopic dermatitis

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Callesen, Michael; Weschler, Charles J.

    2015-01-01

    Studies in rodents indicate that phthalates can function as adjuvants, increasing the potency of allergens. Meanwhile, epidemiological studies have produced inconsistent findings regarding relationships between phthalate exposures and allergic disease in humans. The present study examined phthala...

  20. ANALYSIS OF THE PHTHALATE CONTENT LEVELS IN WINE PRODUCTS

    Directory of Open Access Journals (Sweden)

    Duca Gheorghe

    2011-12-01

    Full Text Available In the context of studies conducted in the laboratory of National Center for Quality Testing of the Alcoholic Beverages (Republic of Moldova were included more than 1300 samples of the bottled wine and base-wine for the presence of most widespread and toxic phthalate – dibutylphthalate using modern method of analysis like GC-MS. Results display presences DBP in 85 % of studied samples of wines, i.e. a content of DBP more than LOQ (0.01mg/dm3. Has been determined that contamination of phthalates has a technogenic character, and it is the result of contact with polymeric materials. Optimum conditions of extraction DBP from liquid samples were obtained.

  1. Hydrogen adsorption in microporous alkali-doped carbons (single-wall carbon nano-tubes and activated carbons)

    International Nuclear Information System (INIS)

    Laurent Duclaux; Szymon Los; Michel Letellier; Philippe Azais; Roland Pellenq; Thomas Roussel; Xavier Fuhr

    2006-01-01

    Doping of microporous carbon by Li or K leads to an increase in the energy of adsorption of H 2 or D 2 molecules. Thus, the room temperature sorption capacities (at P≤3 MPa) can be higher than the ones of the raw materials after slight doping. However, the maximum H 2 (or D 2 ) storage uptake measured at T≤ 77 K is lower than the one of pristine materials as the sites of adsorption are occupied by alkali ions inserted in the micropores. The microporous adsorption sites of doped single-walled carbon nano-tubes, identified by neutron diffraction, are both the interstitial voids (in electric-arc or HiPCO tubes) in between the tubes and the central canals of the tubes (only in HiPCO tubes). (authors)

  2. Production of the Q2 doubly excited states of the hydrogen molecule by electron impact in a single step

    Science.gov (United States)

    Santos, Leonardo O.; Rocha, Alexandre B.; Faria, Nelson Velho de Castro; Jalbert, Ginette

    2017-03-01

    We calculate the single step cross sections for excitation of Q 2 states of H2 and its subsequent dissociation. The cross section calculations were performed within the first Born approximation and the electronic wave functions were obtained via State-Averaged Multiconfigurational Self-Consistent Field followed by Configuration Interaction. We have assumed autoionization is the only important process competing with dissociation into neutral atoms. We have estimated its probability through a semi classical approach and compared with results of literature. Special attention was given to the Q 2 1Σg +(1) state which, as has been shown in a previous work, may dissociate into H(2 sσ) + H(2 sσ) fragments (some figures in this article are in colour only in the electronic version).

  3. Changes in Urinary Phthalate Metabolite Levels Before and After the Phthalate Contamination Event and Identification of Exposure Sources in a Cohort of Taiwanese Children.

    Science.gov (United States)

    Huang, Chian-Feng; Wang, I-Jen

    2017-08-19

    In 2011, the Taiwan Food and Drug Administration inadvertently discovered that, for decades, manufacturers had replaced expensive natural emulsifiers in food products with diethylhexyl phthalate (DEHP). We wanted to compare urinary phthalate metabolite levels of children before and after the DEHP food contamination event and identify source(s) of phthalate exposure in addition to the illegal food additives. In the present study, morning urine samples were collected from a cohort of 453 children in 2010 in Taipei. After the DEHP food contamination event, there were 200 cohort children left at follow-up in 2013. The geometric means (GMs) of urinary mono(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP) levels before and after the event were 9.39 and 13.34 µg/g of creatinine, respectively, with no significant difference ( p = 0.093). After the DEHP food contamination event, we found that urinary phthalate metabolite levels were significantly higher in people who frequently consumed microwave-heated food and used fragrance-containing products ( p food contamination event, thus, other sources must contribute to phthalate exposure in daily life. Public awareness of approaches to reducing phthalate exposure is necessary.

  4. Point-of-Care Determination of Acetaminophen Levels with Multi-Hydrogen Bond Manipulated Single-Molecule Recognition (eMuHSiR).

    Science.gov (United States)

    Zhang, Yan; Huang, Zhongyuan; Wang, Letao; Wang, Chunming; Zhang, Changde; Wiese, Tomas; Wang, Guangdi; Riley, Kevin; Wang, Zhe

    2018-04-03

    This work aims to face the challenge of monitoring small molecule drugs accurately and rapidly for point-of-care (POC) diagnosis in current clinical settings. Overdose of acetaminophen (AP), a commonly used over the counter (OTC) analgesic drug, has been determined to be a major cause of acute liver failure in the US and the UK. However, there is no rapid and accurate detection method available for this drug in the emergency room. The present study examined an AP sensing strategy that relies on a previously unexplored strong interaction between AP and the arginine (Arg) molecule. It was found that as many as 4 hydrogen bonds can be formed between one Arg molecule and one AP molecule. By taking advantages of this structural selectivity and high tenability of hydrogen bonds, Arg, immobilized on a graphene surface via electrostatic interactions, was utilized to structurally capture AP. Interestingly, bonded AP still remained the perfect electrochemical activities. The extent of Arg-AP bonds was quantified using a newly designed electrochemical (EC) sensor. To verify the feasibility of this novel assay, based on multihydrogen bond manipulated single-molecule recognition (eMuHSiR), both pharmaceutical and serum sample were examined. In commercial tablet measurement, no significant difference was seen between the results of eMuHSiR and other standard methods. For measuring AP concentration in the mice blood, the substances in serum, such as sugars and fats, would not bring any interference to the eMuHSiR in a wide concentration range. This eMuHSiR method opens the way for future development of small molecule detection for the POC testing.

  5. Hydrogen interstitial in H-ion implanted ZnO bulk single crystals: Evaluation by elastic recoil detection analysis and electron paramagnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kaida, T.; Kamioka, K.; Nishimura, T. [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kuriyama, K., E-mail: kuri@ionbeam.hosei.ac.jp [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Department of Arts and Sciences, Osaka Kyoiku University, Kashiwara, Osaka 582-8582 (Japan); Kinomura, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

    2015-12-15

    The origins of low resistivity in H ion-implanted ZnO bulk single crystals are evaluated by elastic recoil detection analysis (ERDA), electron paramagnetic resonance (EPR), and Van der Pauw methods. The H-ion implantation (peak concentration: 5.0 × 10{sup 15} cm{sup −2}) into ZnO is performed using a 500 keV implanter. The maximum of the concentration of the implanted H estimated by a TRIM simulation is at 3600 nm in depth. The resistivity decreases from ∼10{sup 3} Ω cm for un implanted ZnO to 6.5 Ω cm for as-implanted, 2.3 × 10{sup −1} Ω cm for 200 °C annealed, and 3.2 × 10{sup −1} Ω cm for 400 °C annealed samples. The ERDA measurements can evaluate the concentration of hydrogens which move to the vicinity of the surface (surface to 300 nm or 100 nm) because of the diffusion by the annealing at 200 °C and 400 °C. The hydrogen concentration near the surface estimated using the 2.0 MeV helium beam is ∼3.8 × 10{sup 13} cm{sup −2} for annealed samples. From EPR measurements, the oxygen vacancy of +charge state (V{sub o}{sup +}) is observed in as-implanted samples. The V{sub o}{sup +} related signal (g = 1.96) observed under no illumination disappears after successive illumination with a red LED and appears again with a blue light illumination. The activation energy of as-implanted, 200 °C annealed, and 400 °C annealed samples estimated from the temperature dependence of carrier concentration lies between 29 meV and 23 meV, suggesting the existence of H interstitial as a shallow donor level.

  6. Efficacy of two hydrogen peroxide vapour aerial decontamination systems for enhanced disinfection of meticillin-resistant Staphylococcus aureus, Klebsiella pneumoniae and Clostridium difficile in single isolation rooms.

    Science.gov (United States)

    Ali, S; Muzslay, M; Bruce, M; Jeanes, A; Moore, G; Wilson, A P R

    2016-05-01

    Hydrogen peroxide vapour (HPV) disinfection systems are being used to reduce patients' exposure to hospital pathogens in the environment. HPV whole-room aerial disinfection systems may vary in terms of operating concentration and mode of delivery. To assess the efficacy of two HPV systems (HPS1 and HPS2) for whole-room aerial disinfection of single isolation rooms (SIRs). Ten SIRs were selected for manual terminal disinfection after patient discharge. Test coupons seeded with biological indicator (BI) organisms [∼10(6) colony-forming units (cfu) of meticillin-resistant Staphylococcus aureus (MRSA) or Klebsiella pneumoniae, or ∼10(5)cfu Clostridium difficile 027 spores] prepared in a soil challenge were placed at five locations per room. For each cycle, 22 high-frequency-touch surfaces in SIRs were sampled with contact plates (∼25cm(2)) before and after HPV decontamination, and BIs were assayed for the persistence of pathogens. Approximately 95% of 214 sites were contaminated with bacteria after manual terminal disinfection, with high numbers present on the SIR floor (238.0-352.5cfu), bed control panel (24.0-33.5cfu), and nurse call button (21.5-7.0cfu). Enhanced disinfection using HPV reduced surface contamination to low levels: HPS1 [0.25cfu, interquartile range (IQR) 0-1.13] and HPS2 (0.5cfu, IQR 0-2.0). Both systems demonstrated similar turnaround times (∼2-2.5h), and no differences were observed in the efficacy of the two systems against BIs (C. difficile ∼5.1log10 reduction; MRSA/K. pneumoniae ∼6.3log10 reduction). Despite different operating concentrations of hydrogen peroxide, MRSA persisted on 27% of coupons after HPV decontamination. Enhanced disinfection with HPV reduces surface contamination left by manual terminal cleaning, minimizing the risks of cross-contamination. The starting concentration and mode of delivery of hydrogen peroxide may not improve the efficacy of decontamination in practice, and therefore the choice of HPV system may

  7. Human breast milk contamination with phthalates and alterations of endogenous reproductive hormones in infants three months of age

    DEFF Research Database (Denmark)

    Main, Katharina M; Mortensen, Gerda Krog; Kaleva, Marko M

    2006-01-01

    Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis.......Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis....

  8. Success and failure with phthalate buffers in capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Boček, Petr; Gebauer, Petr; Beckers, J. L.

    2001-01-01

    Roč. 22, č. 6 (2001), s. 1106-1111 ISSN 0173-0835 R&D Projects: GA AV ČR IAA4031103; GA AV ČR IAA4031703; GA ČR GA203/99/0044; GA ČR GA203/01/0401 Institutional research plan: CEZ:AV0Z4031919 Keywords : phthalate buffer * system peaks * electromigration dispersion Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  9. Di-iso-Butyl Phthalate MATERNAL AND FETAL DATA FROM ...

    Science.gov (United States)

    this file contains the raw data on the effects of in utero administration of di-iso-butyl phthalate on maternal weight gain during dosing and the numbers of fetuses and fetal resorptions. The data have all been previously published, as described on the file metadata sheet. Raw data file from our published studies on DIBP specifically requested (6/14/2016) by NCEA scientists for analysis and inclusion in their assessment of this chemical.

  10. Association between Urine Phthalate Levels and Poor Attentional Performance in Children with Attention-Deficit Hyperactivity Disorder with Evidence of Dopamine Gene-Phthalate Interaction

    Directory of Open Access Journals (Sweden)

    Subin Park

    2014-06-01

    Full Text Available Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4, dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.

  11. Association between urine phthalate levels and poor attentional performance in children with attention-deficit hyperactivity disorder with evidence of dopamine gene-phthalate interaction.

    Science.gov (United States)

    Park, Subin; Kim, Bung-Nyun; Cho, Soo-Churl; Kim, Yeni; Kim, Jae-Won; Lee, Ju-Young; Hong, Soon-Beom; Shin, Min-Sup; Yoo, Hee Jeong; Im, Hosub; Cheong, Jae Hoon; Han, Doug Hyun

    2014-06-27

    Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child's urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.

  12. Association between Urine Phthalate Levels and Poor Attentional Performance in Children with Attention-Deficit Hyperactivity Disorder with Evidence of Dopamine Gene-Phthalate Interaction

    Science.gov (United States)

    Park, Subin; Kim, Bung-Nyun; Cho, Soo-Churl; Kim, Yeni; Kim, Jae-Won; Lee, Ju-Young; Hong, Soon-Beom; Shin, Min-Sup; Yoo, Hee Jeong; Im, Hosub; Cheong, Jae Hoon; Han, Doug Hyun

    2014-01-01

    Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms. PMID:24978879

  13. The solvent effects on dimethyl phthalate investigated by FTIR characterization, solvent parameter correlation and DFT computation

    Science.gov (United States)

    Chen, Yi; Zhang, Hui; Zhou, Wenzhao; Deng, Chao; Liao, Jian

    2018-06-01

    This study set out with the aim of investigating the solvent effects on dimethyl phthalate (DMP) using FTIR characterization, solvent parameter correlation and DFT calculation. DMP exposed to 17 organic solvents manifested varying shift in the carbonyl stretching vibration frequency (νCdbnd O). Non-alkanols induced Band I and alkanols produced Band I and Band II. Through correlating the νCdbnd O with the empirical solvent scales including acceptor parameter (AN), Schleyer's linear free energy parameter (G), and linear free salvation energy relationships (LSER), Band I was mainly ascribed to non-specific effects from either non-alkanols or alkanol polymers ((alkanol)n). νCdbnd O of the latter indicated minor red shift and less variability compared to the former. An assumption was made and validated about the sequestering of hydroxyl group by the bulky hydrophobic chain in (alkanol)n, creating what we refer to as "screening effects". Ab initio calculation, on the other hand, provided insights for possible hydrogen binding between DMP and (ethanol)n or between ethanol monomers. The two components of Band I observed in inert solvents were assigned to the two Cdbnd O groups adopting differentiated conformations. This in turn prompted our consideration that hydrogen binding was highly selective in favor of lowly associated (alkanol)n and the particular Cdbnd O group having relatively less steric hindrance and stronger electron-donating capacity. Band II was therefore believed to derive from hydrogen-bond interactions mainly in manner of 1:1 and 1:2 DMP-(alkanol)n complexes.

  14. (Lu.sub.0.8./sub.Ce.sub.0.2./sub.).sub.2./sub.Fe.sub.17./sub. single crystal under hydrostatic and ‘negative’ pressure induced by hydrogenation

    Czech Academy of Sciences Publication Activity Database

    Tereshina, Evgeniya; Andreev, Alexander V.; Kamarád, Jiří; Isnard, O.; Watanabe, K.

    2011-01-01

    Roč. 23, č. 21 (2011), s. 1-9 ISSN 0953-8984 R&D Projects: GA ČR GA202/09/0339 Institutional research plan: CEZ:AV0Z10100520 Keywords : hydrogenation * single-crystalline compounds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.546, year: 2011

  15. Study on the leaching of phthalates from polyethylene terephthalate bottles into mineral water

    International Nuclear Information System (INIS)

    Keresztes, Szilvia; Tatár, Enikő; Czégény, Zsuzsanna; Záray, Gyula; Mihucz, Victor G.

    2013-01-01

    Carbonated and non-carbonated mineral water samples bottled in 0.5-L, 1.5-L and 2.0-L polyethylene terephthalate (PET) containers belonging to three different water brands commercialized in Hungary were studied in order to determine their phthalate content by gas chromatography–mass spectrometry. Among the six investigated phthalates, diisobutyl phthalate, di-n-butyl-phthalate, benzyl-butyl phthalate and di(2-ethyl-hexyl) phthalate (DEHP) were determined in non-carbonated samples as follows: −1 –0.2 μg L −1 , −1 –0.8 μg L −1 , −1 –0.1 μg L −1 and −1 –1.7 μg L −1 , respectively. Any of the above-mentioned phthalate esters could be detected in carbonated mineral water samples. DEHP was the most abundant phthalate in the investigated samples. It could be detected after 44 days of storage at 22 °C and its leaching was the most pronounced when samples were stored over 1200 days. Mineral water purchased in PET bottles of 0.5 L had the highest phthalate concentrations compared to those obtained for waters of the identical brand bottled in 1.5-L or 2.0-L PET containers due to the higher surface/volume ratio. No clear trend could be established for phthalate leaching when water samples were kept at higher temperatures (max. 60 °C) showing improper storage conditions. Phthalate determination by pyrolysis–gas chromatography/mass spectrometric measurements in the plastic material as well as in the aqueous phase proved the importance of the quality of PET raw material used for the production of the pre-form (virgin vs. polymer containing recycled PET). - Highlights: • DEHP — most abundant phthalate in bottled mineral water • Temperature and contact surface area influence phthalate leaching. • Phthalate occurrence depends on virgin vs. polymer containing recycled PET. • pH (carbonated vs. non-carbonated samples) affects hydrolysis of phthalate esters

  16. Study on the leaching of phthalates from polyethylene terephthalate bottles into mineral water

    Energy Technology Data Exchange (ETDEWEB)

    Keresztes, Szilvia; Tatár, Enikő [Laboratory of Environmental Chemistry and Bioanalytics, Department of Analytical Chemistry, Institute of Chemistry, Eötvös Loránd University, H-1117 Budapest, Pázmány Péter sétány 1/A (Hungary); Czégény, Zsuzsanna [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1525 Budapest, P.O. Box 17 (Hungary); Záray, Gyula [Laboratory of Environmental Chemistry and Bioanalytics, Department of Analytical Chemistry, Institute of Chemistry, Eötvös Loránd University, H-1117 Budapest, Pázmány Péter sétány 1/A (Hungary); Mihucz, Victor G., E-mail: vigami72@yahoo.es [Laboratory of Environmental Chemistry and Bioanalytics, Department of Analytical Chemistry, Institute of Chemistry, Eötvös Loránd University, H-1117 Budapest, Pázmány Péter sétány 1/A (Hungary)

    2013-08-01

    Carbonated and non-carbonated mineral water samples bottled in 0.5-L, 1.5-L and 2.0-L polyethylene terephthalate (PET) containers belonging to three different water brands commercialized in Hungary were studied in order to determine their phthalate content by gas chromatography–mass spectrometry. Among the six investigated phthalates, diisobutyl phthalate, di-n-butyl-phthalate, benzyl-butyl phthalate and di(2-ethyl-hexyl) phthalate (DEHP) were determined in non-carbonated samples as follows: < 3.0 ng L{sup −1}–0.2 μg L{sup −1}, < 6.6 ng L{sup −1}–0.8 μg L{sup −1}, < 6.0 ng L{sup −1}–0.1 μg L{sup −1} and < 16.0 ng L{sup −1}–1.7 μg L{sup −1}, respectively. Any of the above-mentioned phthalate esters could be detected in carbonated mineral water samples. DEHP was the most abundant phthalate in the investigated samples. It could be detected after 44 days of storage at 22 °C and its leaching was the most pronounced when samples were stored over 1200 days. Mineral water purchased in PET bottles of 0.5 L had the highest phthalate concentrations compared to those obtained for waters of the identical brand bottled in 1.5-L or 2.0-L PET containers due to the higher surface/volume ratio. No clear trend could be established for phthalate leaching when water samples were kept at higher temperatures (max. 60 °C) showing improper storage conditions. Phthalate determination by pyrolysis–gas chromatography/mass spectrometric measurements in the plastic material as well as in the aqueous phase proved the importance of the quality of PET raw material used for the production of the pre-form (virgin vs. polymer containing recycled PET). - Highlights: • DEHP — most abundant phthalate in bottled mineral water • Temperature and contact surface area influence phthalate leaching. • Phthalate occurrence depends on virgin vs. polymer containing recycled PET. • pH (carbonated vs. non-carbonated samples) affects hydrolysis of phthalate esters.

  17. Racial and ethnic variations in phthalate metabolite concentration changes across full-term pregnancies.

    Science.gov (United States)

    James-Todd, Tamarra M; Meeker, John D; Huang, Tianyi; Hauser, Russ; Seely, Ellen W; Ferguson, Kelly K; Rich-Edwards, Janet W; McElrath, Thomas F

    2017-03-01

    Higher concentrations of certain phthalate metabolites are associated with adverse reproductive and pregnancy outcomes, as well as poor infant/child health outcomes. In non-pregnant populations, phthalate metabolite concentrations vary by race/ethnicity. Few studies have documented racial/ethnic differences between phthalate metabolite concentrations at multiple time points across the full-course of pregnancy. The objective of the study was to characterize the change in phthalate metabolite concentrations by race/ethnicity across multiple pregnancy time points. Women were participants in a prospectively collected pregnancy cohort who delivered at term (≥37 weeks) and had available urinary phthalate metabolite concentrations for ≥3 time points across full-term pregnancies (n=350 women). We assessed urinary concentrations of eight phthalate metabolites that were log-transformed and specific gravity-adjusted. We evaluated the potential racial/ethnic differences in phthalate metabolite concentrations at baseline (median 10 weeks gestation) using ANOVA and across pregnancy using linear mixed models to calculate the percent change and 95% confidence intervals adjusted for sociodemographic and lifestyle factors. Almost 30% of the population were non-Hispanic black or Hispanic. With the exception of mono-(3-carboxypropyl) (MCPP) and di-ethylhexyl phthalate (DEHP) metabolites, baseline levels of phthalate metabolites were significantly higher in non-whites (Pethnicity, mono-ethyl phthalate (MEP) and MCPP had significant percent changes across pregnancy. MEP was higher in Hispanics at baseline and decreased in mid-pregnancy but increased in late pregnancy for non-Hispanic blacks. MCPP was substantially higher in non-Hispanic blacks at baseline but decreased later in pregnancy. Across pregnancy, non-Hispanic black and Hispanic women had higher concentrations of certain phthalate metabolites. These differences may have implications for racial/ethnic differences in adverse

  18. Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment.

    Science.gov (United States)

    Li, Hai-Ling; Song, Wei-Wei; Zhang, Zi-Feng; Ma, Wan-Li; Gao, Chong-Jing; Li, Jia; Huo, Chun-Yan; Mohammed, Mohammed O A; Liu, Li-Yan; Kannan, Kurunthachalam; Li, Yi-Fan

    2016-09-15

    Phthalates are widely used chemicals in household products, which severely affect human health. However, there were limited studies emphasized on young adults' exposure to phthalates in dormitories. In this study, seven phthalates were extracted from indoor dust that collected in university dormitories in Harbin, Shenyang, and Baoding, in the north of China. Dust samples were also collected in houses in Harbin for comparison. The total concentrations of phthalates in dormitory dust in Harbin and Shenyang samples were significantly higher than those in Baoding samples. The total geometric mean concentration of phthalates in dormitory dust in Harbin was lower than in house dust. Di-(2-ethylhexyl) phthalate (DEHP) was the most abundant phthalate in both dormitory and house dust. The daily intakes of the total phthalates, carcinogenic risk (CR) of DEHP, hazard index (HI) of di-isobutyl phthalate (DiBP), dibutyl phthalate (DBP), and DEHP were estimated, the median values for all students in dormitories were lower than adults who live in the houses. Monte Carlo simulation was applied to predict the human exposure risk of phthalates. HI of DiBP, DBP, and DEHP was predicted according to the reference doses (RfD) provided by the United States Environmental Protection Agency (U.S.EPA) and the reference doses for anti-androgenicity (RfD AA) developed by Kortenkamp and Faust. The results indicated that the risks of some students had exceeded the limitation, however, the measured results were not exceeded the limitation. Risk quotients (RQ) of DEHP were predicted based on China specific No Significant Risk Level (NSRL) and Maximum Allowable Dose Level (MADL). The predicted results of CR and RQ of DEHP suggested that DEHP could pose a health risk through intake of indoor dust. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Characterization of phthalates exposure and risk for cosmetics and perfume sales clerks.

    Science.gov (United States)

    Huang, Po-Chin; Liao, Kai-Wei; Chang, Jung-Wei; Chan, Shiou-Hui; Lee, Ching-Chang

    2018-02-01

    High levels of phthalates in name-brand cosmetics products have raised concerns about phthalate exposure and the associated risk for cosmetics sales clerks. We assessed the exposure and risk of phthalates in 23 cosmetics, 4 perfume, and 9 clothing department store sales clerks. We collected 108 urine samples pre- and post-shift and analyzed for phthalate monoesters through liquid chromatography-electrospray ionization-tandem mass spectrometry. Phthalates in 32 air samples were collected and analyzed through gas chromatography-mass spectrometry. Demographic characteristics and information on the exposure scenarios were obtained through questionnaires. Principal component analysis, cluster and risk analysis were applied to identify the exposure profile and risk of phthalate. Median post-shift levels of urinary mono-2-ethylhexyl phthalate (MEHP) and monomethyl phthalate (MMP) were significantly higher than the corresponding pre-shift levels in cosmetics group (53.3 vs. 30.9 μg/g-c for MEHP; 34.4 vs. 22.5 μg/g-c for MMP; both P perfume group (26.6 vs. 14.9 μg/g-c, P perfume (1.75 μg/m 3 ) groups and di-(2-ethylhexyl) phthalate (DEHP) in perfume group (6.98 μg/m 3 ) were higher than those in clothing group (DEP: 0.89; DEHP: 2.16 μg/m 3 ). Over half of cosmetic (70%) and perfume sale clerks had exceeded cumulative risk of phthalate exposure for anti-androgenic effect. We concluded that cosmetic and perfume workers had increased risks of reproductive or hepatic effects for DBP and DEHP exposure. We suggest that not only inhalation but dermal exposure is important route of phthalate exposure for cosmetics and perfume workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Early Phthalates Exposure in Pregnant Women Is Associated with Alteration of Thyroid Hormones.

    Directory of Open Access Journals (Sweden)

    Po-Chin Huang

    Full Text Available Previous studies revealed that phthalate exposure could alter thyroid hormones during the last trimester of pregnancy. However, thyroid hormones are crucial for fetal development during the first trimester. We aimed to clarify the effect of phthalate exposure on thyroid hormones during early pregnancy.We recruited 97 pregnant women who were offered an amniocentesis during the early trimester from an obstetrics clinic in southern Taiwan from 2013 to 2014. After signing an informed consent form, we collected amniotic fluid and urine samples from pregnant women to analyze 11 metabolites, including mono-ethyl phthalate (MEP, mono-(2-ethyl-5-carboxypentyl phthalate (MECPP, mono-(2-ethylhexyl phthalate (MEHP, mono-butyl phthalate (MnBP, of 9 phthalates using liquid chromatography/ tandem mass spectrometry. We collected blood samples from each subject to analyze serum thyroid hormones including thyroxine (T4, free T4, and thyroid-binding globulin (TBG.Three phthalate metabolites were discovered to be >80% in the urine samples of the pregnant women: MEP (88%, MnBP (81% and MECPP (86%. Median MnBP and MECPP levels in pregnant Taiwanese women were 21.5 and 17.6 μg/g-creatinine, respectively, that decreased after the 2011 Taiwan DEHP scandal. Results of principal component analysis suggested two major sources (DEHP and other phthalates of phthalates exposure in pregnant women. After adjusting for age, gestational age, TBG, urinary creatinine, and other phthalate metabolites, we found a significantly negative association between urinary MnBP levels and serum T4 (β = -5.41; p-value = 0.012; n = 97 in pregnant women using Bonferroni correction.We observed a potential change in the thyroid hormones of pregnant women during early pregnancy after DnBP exposure. Additional study is necessitated to clarify these associations.

  1. Phthalate exposure associated with self-reported diabetes among Mexican women.

    Science.gov (United States)

    Svensson, Katherine; Hernández-Ramírez, Raúl U; Burguete-García, Ana; Cebrián, Mariano E; Calafat, Antonia M; Needham, Larry L; Claudio, Luz; López-Carrillo, Lizbeth

    2011-08-01

    Phthalates are ubiquitous industrial chemicals used as plasticizers in plastics made of polyvinyl chloride (PVC) to confer flexibility and durability. They are also present in products used for personal-care, industry and in medical devices. Phthalates have been associated with several adverse health effects, and recently it has been proposed that exposure to phthalates, could have an effect on metabolic homeostasis. This exploratory cross-sectional study evaluated the possible association between phthalate exposure and self-reported diabetes among adult Mexican women. As part of an on-going case-control study for breast cancer, only controls were selected, which constituted 221 healthy women matched by age (±5 years) and place of residence with the cases. Women with diabetes were identified by self-report. Urinary concentrations of nine phthalate metabolites were measured by online solid phase extraction coupled to high performance liquid chromatography-isotope-dilution tandem mass spectrometry. Participants with diabetes had significantly higher concentrations of di(2-ethylhexyl) pththalate (DEHP) metabolites: mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) but lower levels of monobenzyl phthalate (MBzP) a metabolite of benzylbutyl phthalate, compared to participants without diabetes. A marginally significant positive associations with diabetes status were observed over tertiles with MEHHP (OR(T3 vs. T1)=2.66; 95% CI: 0.97-7.33; p for trend=0.063) and MEOHP (OR(T3 vs. T1)=2.27; 95% CI; 0.90-5.75; P for trend=0.079) even after adjusting for important confounders. The results suggest that levels of some phthalates may play a role in the genesis of diabetes. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Research of thermostability of phthalates of oxyalkylated alcohols

    Directory of Open Access Journals (Sweden)

    MAZITOVA Aliya Karamovna

    2018-04-01

    Full Text Available The production of polyvinyl chloride (PVC requires implication of a large number of plasticizers. Ester compounds are the most suitable for plasticization. Currently the existing range of industrial plasticizers does not satisfy a need of the polymer industry and it is of great importance to develop new plasticizers that meet modern requirements. Therefore, the elaboration of new ester compounds with effective plasticizing properties, is relevant and has not only scientific value, but also practical one. One of the basic requirements for ester plasticizers is their resistance to thermal oxidation. Accordingly, we considered the effect of oxygen at 150оC (the temperature of conversion of PVC-plastic compounds on a wide range of oxyalated alcohol phthalates developed earlier. The first group consisted of aromatic alcohols, the second group – phthalates of oxyalkylated aliphatic alcohols. The first group showed high thermal stability, the latter should be stabilized by the addition of antioxidants. It is known that aromatic hydrocarbon derivatives are widely used as tabilizers of thermooxidative disrupture. The main function of the mentioned compounds is to suppress the catalytic action of air oxygen in energy impacts on polymers and plasticizers. Consequently, we investigated the effect of Agidol-1 on increasing the stability of phthalate plasticizers to thermaloxidative degradation.

  3. Iron(III) protoporphyrin IX-single-wall carbon nanotubes modified electrodes for hydrogen peroxide and nitrite detection

    International Nuclear Information System (INIS)

    Turdean, Graziella L.; Popescu, Ionel Catalin; Curulli, Antonella; Palleschi, Giuseppe

    2006-01-01

    Iron(III) protoporphyrin IX (Fe(III)P), adsorbed either on single-walled carbon nanotubes (SWCNT) or on hydroxyl-functionalized SWCNT (SWCNT-OH), was incorporated within a Nafion matrix immobilized on the surface of a graphite electrode. From cyclic voltammetric measurements, performed under different experimental conditions (pH and potential scan rate), it was established that the Fe(III)P/Fe(II)P redox couple involves 1e - /1H + . The heterogeneous electron transfer process occurred faster when Fe(III)P was adsorbed on SWCNT-OH (∼11 s -1 ) than on SWCNT (∼4.9 s -1 ). Both the SWCNT-Fe(III)P- and SWCNT-OH-Fe(III)P-modified graphite electrodes exhibit electrocatalytic activity for H 2 O 2 and nitrite reduction. The modified electrodes sensitivities were found varying in the following sequences: S SWCNT-OH-Fe(III)P = 2.45 mA/M ∼ S SWCNT-Fe(III)P = 2.95 mA/M > S Fe(III)P = 1.34 mA/M for H 2 O 2 , and S SWCNT-Fe(III)P = 3.54 mA/M > S Fe(III)P 1.44 mA/M > S SWCNT-OH-Fe(III)P = 0.81 mA/M for NO 2 -

  4. Exposure to phthalates among premenstrual girls from rural and urban Gharbiah, Egypt: A pilot exposure assessment study

    Directory of Open Access Journals (Sweden)

    Hablas Ahmed

    2011-05-01

    Full Text Available Abstract Background Phthalates have been identified as endocrine active compounds associated with developmental and reproductive toxicity. The exposure to phthalates in premenstrual Egyptian females remains unknown. The objective of this study was to characterize phthalate exposure of a potentially vulnerable population of premenstrual girls from urban and rural Egypt. Materials and methods We collected one spot urine sample from 60 10-13 year old females, 30 from rural Egypt, and 30 from urban Egypt from July to October 2009. Samples were analyzed for 11 phthalate metabolites. Additionally, we collected anthropometrics as well as questionnaire data concerning food storage behaviors, cooking practices, and cosmetic use. Phthalate metabolite concentrations were compared between urban and rural Egyptians as well as to age and gender matched Americans. Results Monoethyl phthalate (MEP, was detected at the highest concentration in urine of Egyptian girls (median: 43.2 ng/mL in rural, 98.8 ng/mL in urban. Concentrations of urinary metabolites of di-(2-ethylhexyl phthalate and dibutyl phthalate were comparable between Egyptians and age matched US girls. Storage of food in plastic containers was a statistically significant predictor of urinary mono-isobutyl phthalate (MiBP concentrations when comparing covariate adjusted means. Conclusions Urinary concentrations of phthalate metabolites were similar in Egyptian and US populations, suggesting that phthalate exposure also occurs in developing nations. Dietary intake is likely an important route of exposure to phthalates in both urban and rural populations.

  5. Analysis of phthalate ester content in poly(vinyl chloride) plastics by means of Fourier transform Raman spectroscopy

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Fourier transform (FT) Raman spectroscopy is applied to a range of phthalate ester plasticizers in pure form as well as in poly(vinyl chloride) (PVC) samples. It is found that phthalate esters as a group can be identified by a set of six characteristic Raman bands. FT-Raman spectra of 22 phthalate...

  6. Using exposure prediction tools to link exposure and dosimetry for risk-based decisions: A case study with phthalates

    Science.gov (United States)

    A few different exposure prediction tools were evaluated for use in the new in vitro-based safety assessment paradigm using di-2-ethylhexyl phthalate (DEHP) and dibutyl phthalate (DnBP) as case compounds. Daily intake of each phthalate was estimated using both high-throughput (HT...

  7. HYDROGEN VACANCY INTERACTION IN MOLYBDENUM

    NARCIS (Netherlands)

    Abd El Keriem, M.S.; van der Werf, D.P.; Pleiter, F

    1993-01-01

    Vacancy-hydrogen interaction in molybdenum was investigated by means of the perturbed angular correlation technique, using the isotope In-111 as a probe. The complex InV2 turned out to trap up to two hydrogen atoms: trapping of a single hydrogen atom gives rise to a decrease of the quadrupole

  8. Hydrogen peroxide modulates Ca2+-activation of single permeabilized fibres from fast- and slow-twitch skeletal muscles of rats.

    Science.gov (United States)

    Plant, D R; Lynch, G S; Williams, D A

    2000-01-01

    We examined the effects of redox modulation on single membrane-permeabilized fibre segments from the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of adult rats to determine whether the contractile apparatus was the redox target responsible for the increased contractility of muscles exposed to low concentrations of H2O2. The effects of H2O2 on maximum Ca2+-activated force were dose-dependent with 30 min exposure to 5 mM H2O2 causing a progressive decrease by 22+/-3 and 13+/-2% in soleus and EDL permeabilized muscle fibres, respectively. Lower concentrations of exogenous H2O2 (100 microM and 1 mM) had no effect on maximum Ca2+-activated force. Subsequent exposure to the reductant dithiothreitol (DTT, 10 mM, 10 min) fully reversed the H2O2-induced depression of force in EDL, but not in soleus muscle fibres. Incubation with DTT alone for 10 min did not alter Ca2+-activated force in either soleus or EDL muscle fibres. The sensitivity of the contractile filaments to Ca2+ (pCa50) was not altered by exposure to any concentration of exogenous H2O2. However, all concentrations of H2O2 diminished the Hill coefficient in permeabilized fibres from the EDL muscle, indicating that the cooperativity of Ca2+ binding to troponin is altered. H2O2 (5 mM) did not affect rigor force, which indicates that the number of crossbridges participating in contraction was not reduced. In conclusion, H2O2 may reduce the maximum Ca2+ activated force production in skinned muscle fibres by decreasing the force per crossbridge.

  9. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    . A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling......This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up...

  10. EXPERIMENTAL INVESTIGATIONS ON THE EFFECT OF HYDROGEN INDUCTION ON PERFORMANCE AND EMISSION BEHAVIOUR OF A SINGLE CYLINDER DIESEL ENGINE FUELLED WITH PALM OIL METHYL ESTER AND ITS BLEND WITH DIESEL

    Directory of Open Access Journals (Sweden)

    BOOPATHI D.

    2017-07-01

    Full Text Available Internal combustion engines are an integral part of our daily lives, especially in the agricultural and transportation sector. With depleting fossil fuel and increasing environmental pollution, the researchers are foraying into alternate sources for fuelling the internal combustion engine. Vegetable oils derived from plant seeds is one such solution, but using them in unmodified diesel engine leads to reduced thermal efficiency and increased smoke emissions. Hydrogen if induced in small quantities in the air intake manifold can enhance the engine performance running on biodiesel. In this work, experiments were performed to evaluate the engine performance when hydrogen was inducted in small quantities and blends of esterified palm oil and diesel was injected as pilot fuel in the conventional manner. Tests were performed on a single cylinder, 4 - stroke, water cooled, direct injection diesel engine running at constant speed of 1500 rpm under variable load conditions and varying hydrogen flow. At full load for 75D25POME (a blend of 75% diesel and 25% palm oil methyl ester by volume, the results indicated an increase in brake thermal efficiency from 29.75% with zero hydrogen flow to a maximum of 30.17% at 5lpm hydrogen flow rate. HC emission reduced from 34 to 31.5 ppm, by volume at maximum load. Whereas, CO emission reduced from 0.09 to 0.045 % by volume at maximum load. Due to higher combustion rates with hydrogen induction, NOx emission increased from 756 to 926 ppm, at maximum load.

  11. Epigenetic Effects of Environmental Chemicals Bisphenol A and Phthalates

    Directory of Open Access Journals (Sweden)

    Steven Shoei-Lung Li

    2012-08-01

    Full Text Available The epigenetic effects on DNA methylation, histone modification, and expression of non-coding RNAs (including microRNAs of environmental chemicals such as bisphenol A (BPA and phthalates have expanded our understanding of the etiology of human complex diseases such as cancers and diabetes. Multiple lines of evidence from in vitro and in vivo models have established that epigenetic modifications caused by in utero exposure to environmental toxicants can induce alterations in gene expression that may persist throughout life. Epigenetics is an important mechanism in the ability of environmental chemicals to influence health and disease, and BPA and phthalates are epigenetically toxic. The epigenetic effect of BPA was clearly demonstrated in viable yellow mice by decreasing CpG methylation upstream of the Agouti gene, and the hypomethylating effect of BPA was prevented by maternal dietary supplementation with a methyl donor like folic acid or the phytoestrogen genistein. Histone H3 was found to be trimethylated at lysine 27 by BPA effect on EZH2 in a human breast cancer cell line and mice. BPA exposure of human placental cell lines has been shown to alter microRNA expression levels, and specifically, miR-146a was strongly induced by BPA treatment. In human breast cancer MCF7 cells, treatment with the phthalate BBP led to demethylation of estrogen receptor (ESR1 promoter-associated CpG islands, indicating that altered ESR1 mRNA expression by BBP is due to aberrant DNA methylation. Maternal exposure to phthalate DEHP was also shown to increase DNA methylation and expression levels of DNA methyltransferases in mouse testis. Further, some epigenetic effects of BPA and phthalates in female rats were found to be transgenerational. Finally, the available new technologies for global analysis of epigenetic alterations will provide insight into the extent and patterns of alterations between human normal and diseased tissues.

  12. High density hydrogen research

    International Nuclear Information System (INIS)

    Hawke, R.S.

    1977-01-01

    The interest in the properties of very dense hydrogen is prompted by its abundance in Saturn and Jupiter and its importance in laser fusion studies. Furthermore, it has been proposed that the metallic form of hydrogen may be a superconductor at relatively high temperatures and/or exist in a metastable phase at ambient pressure. For ten years or more, laboratories have been developing the techniques to study hydrogen in the megabar region (1 megabar = 100 GPa). Three major approaches to study dense hydrogen experimentally have been used, static presses, shockwave compression, and magnetic compression. Static tchniques have crossed the megabar threshold in stiff materials but have not yet been convincingly successful in very compressible hydrogen. Single and double shockwave techniques have improved the precision of the pressure, volume, temperature Equation of State (EOS) of molecular hydrogen (deuterium) up to near 1 Mbar. Multiple shockwave and magnetic techniques have compressed hydrogen to several megabars and densities in the range of the metallic phase. The net result is that hydrogen becomes conducting at a pressure between 2 and 4 megabars. Hence, the possibility of making a significant amount of hydrogen into a metal in a static press remains a formidable challenge. The success of such experiments will hopefully answer the questions about hydrogen's metallic vs. conducting molecular phase, superconductivity, and metastability. 4 figures, 15 references

  13. Phthalate Exposure and Health-Related Outcomes in Specific Types of Work Environment

    Directory of Open Access Journals (Sweden)

    Branislav Kolena

    2014-05-01

    Full Text Available Many toxic substances in the workplace can modify human health and quality of life and there is still insufficient data on respiratory outcomes in adults exposed to phthalates. The aim of this work was to assess in waste management workers from the Nitra region of Slovakia (n = 30 the extent of exposure to phthalates and health-related outcomes. Four urinary phthalate metabolites mono(2-ethylhexyl phthalate (MEHP, monobutyl phthalate (MnBP, monoethyl phthalate (MEP and monoisononyl phthalate (MiNP were determined by high-performance liquid chromatography with mass spectrometry (HPLC-MS/MS. Urinary concentration of MEHP was positively associated with ratio of forced expiratory volume in 1 s to forced vital capacity % (FEV1/FVC (r = 0.431; p = 0.018 and MiNP with fat free mass index (FFMI (r = 0.439; p = 0.015. The strongest predictor of pulmonary function was the pack/year index as smoking history that predicted a decrease of pulmonary parameters, the FEV1/FVC, % of predicted values of peak expiratory flow (PEF % of PV and FEV1 % of PV. Unexpectedly, urinary MEHP and MINP were positively associated with pulmonary function expressed as PEF % of PV and FEV1/FVC. We hypothesize that occupational exposure to phthalates estimated from urinary metabolites (MEHP, MiNP can modify pulmonary function on top of lifestyle factors.

  14. Effects of early exposure to phthalates and bisphenols on cardiometabolic outcomes in pregnancy and childhood

    NARCIS (Netherlands)

    Philips, E.M. (Elise M.); V.W.V. Jaddoe (Vincent); Trasande, L. (Leonardo)

    2017-01-01

    textabstractPregnant women are exposed to various chemicals, including endocrine-disrupting chemicals (EDCs) such as phthalates and bisphenols. Increasing evidence suggests that early life exposures to phthalates and bisphenols may contribute to cardiometabolic risks. The aim of this narrative

  15. Associations between serum phthalates and biomarkers of reproductive function in 589 adult men

    DEFF Research Database (Denmark)

    Specht, Ina Olmer; Toft, Gunnar; Hougaard, Karin S

    2014-01-01

    Phthalates which are widely used, are ubiquitous in the environment and in some human tissues. It is generally accepted that phthalates exert their toxic action by inhibiting Leydig cell synthesis of testosterone, but in vitro studies have also shown anti-androgenic effects at the receptor level...

  16. Prenatal Phthalate Exposure and Language Development in Toddlers from the Odense Child Cohort

    DEFF Research Database (Denmark)

    Olesen, Trine Staak; Bleses, Dorthe; Andersen, Helle Raun

    2018-01-01

    Background Phthalates are a group of chemicals found in a variety of consumer products. They have anti-androgenic properties and human studies have reported associations between prenatal phthalate exposure and neuropsychological development in the offspring despite different cognitive tests, diff...

  17. Serum phthalate levels and time to pregnancy in couples from Greenland, Poland and Ukraine

    DEFF Research Database (Denmark)

    Specht, Ina Olmer; Bonde, Jens Peter; Toft, Gunnar

    2015-01-01

    levels of diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP) metabolites in both partners. In 2002-2004 we enrolled 938 pregnant women and 401 male spouses from Greenland, Poland and Ukraine. Six oxidized metabolites of DEHP and DiNP were summarized for each of the two parent compounds...

  18. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring - A Mechanistic Analysis

    Science.gov (United States)

    A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Adsorption isotherms for phthalates and plasticizers on interior ...

  19. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring: Sensitivity, Uncertainty, and Implications for Biomonitoring

    Science.gov (United States)

    Given the ubiquitous nature of phthalates in the environment and the potential for adverse human health impacts, there is a need to understand the potential human exposure. A three-compartment model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) f...

  20. Phthalate and PAH concentrations in dust collected from Danish homes and daycare centers

    DEFF Research Database (Denmark)

    Langer, Sarka; Weschler, Charles J.; Fischer, Andreas

    2010-01-01

    (diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP)) and three PAHs (pyrene, benz[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P)). The three PAHs and DEHP were detected in dust samples from all sites, while...... DEP. DnBP, DiBP and BBzP were detected in more than 75% of the bedrooms and more than 90% of the daycare centers. The dust mass-fractions of both phthalates and PAHs were log-normally distributed. With the exception of DEP, the mass-fractions of phthalates in dust were higher in daycare centers than...... homes: PAH mass-fractions in dust were similar in the two locations. There was no correlation among the different phthalates in either homes or daycare centers. In contrast, the PAH were correlated with one another more strongly so in homes (R-2 = 0.80-0.90) than in daycare centers (R-2 = 0...

  1. Oxidative DNA damage in male wistar rats exposed to di-n-butyl phthalate

    DEFF Research Database (Denmark)

    Wellejus, A.; Dalgaard, Majken; Loft, S.

    2002-01-01

    Dialkyl phthalate esters are used in the plastic industry and widely distributed in the environment, Previously, it has been shown that di-n-butyl phthalate (DBP) produces testicular atrophy and liver enlargement in rodents, and the mechanisms behind this could involve reactive oxygen species (ROS...

  2. Partitioning of phthalates among the gas phase, airborne particles and settled dust in indoor environments

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Salthammer, Tunga; Fromme, Hermann

    2008-01-01

    (s)) or the octanol/air partition coefficient (K-OA). For each phthalate in each apartment, the ratio of its particle concentration to its dust concentration (C-particle/C-Dust) was calculated, The median values of this ratio were within an order of magnitude of one another for five of the phthalate esters despite...

  3. Phthalates impact human health: Epidemiological evidences and plausible mechanism of action.

    Science.gov (United States)

    Benjamin, Sailas; Masai, Eiji; Kamimura, Naofumi; Takahashi, Kenji; Anderson, Robin C; Faisal, Panichikkal Abdul

    2017-10-15

    Disregarding the rising alarm on the hazardous nature of various phthalates and their metabolites, ruthless usage of phthalates as plasticizer in plastics and as additives in innumerable consumer products continues due low their cost, attractive properties, and lack of suitable alternatives. Globally, in silico computational, in vitro mechanistic, in vivo preclinical and limited clinical or epidemiological human studies showed that over a dozen phthalates and their metabolites ingested passively by man from the general environment, foods, drinks, breathing air, and routine household products cause various dysfunctions. Thus, this review addresses the health hazards posed by phthalates on children and adolescents, epigenetic modulation, reproductive toxicity in women and men; insulin resistance and type II diabetes; overweight and obesity, skeletal anomalies, allergy and asthma, cancer, etc., coupled with the description of major phthalates and their general uses, phthalate exposure routes, biomonitoring and risk assessment, special account on endocrine disruption; and finally, a plausible molecular cross-talk with a unique mechanism of action. This clinically focused comprehensive review on the hazards of phthalates would benefit the general population, academia, scientists, clinicians, environmentalists, and law or policy makers to decide upon whether usage of phthalates to be continued swiftly without sufficient deceleration or regulated by law or to be phased out from earth forever. Copyright © 2017. Published by Elsevier B.V.

  4. CLONING AND CHARACTERIZATION OF THE PHTHALATE CATABOLISM REGION OF PRE1 OF ARTHROBACTER KEYSERI 12B

    Science.gov (United States)

    o-Phthalate (benzene-1,2-dicarboxylate) is a central intermediate in the bacterial degradation of phthalate ester plasticizers as well as of a number of fused-ring polycyclic aromatic hydrocarbons found in fossil fuels. In Arthrobacter keyseri 12B, the genes encoding catabolism o...

  5. Associations between serum phthalates and biomarkers of reproductive function in 589 adult men

    NARCIS (Netherlands)

    Specht, Ina Olmer; Toft, Gunnar; Hougaard, Karin S.; Lindh, Christian H.; Lenters, Virissa|info:eu-repo/dai/nl/314850171; Jonsson, Bo A. G.; Heederik, Dick|info:eu-repo/dai/nl/072910542; Giwercman, Aleksander; Bonde, Jens Peter E.

    Phthalates which are widely used, are ubiquitous in the environment and in some human tissues. It is generally accepted that phthalates exert their toxic action by inhibiting Leydig cell synthesis of testosterone, but in vitro studies have also shown anti-androgenic effects at the receptor level.

  6. Urinary phthalate metabolites and their biotransformation products: predictors and temporal variability among men and women

    Science.gov (United States)

    Meeker, John D.; Calafat, Antonia M.; Hauser, Russ

    2012-01-01

    Most epidemiology studies investigating potential adverse health effects in relation to phthalates measure the urinary concentration of the free plus glucuronidated species of phthalate metabolites (i.e., total concentration) to estimate exposure. However, the free species may represent the biologically relevant dose. In this study, we collected 943 urine samples from 112 men and 157 women and assessed the between- and within-person variability and predictors of a) the free and total urinary concentrations of phthalate metabolites, and b) the percentage of free phthalate metabolites (a potential phenotypic indicator of individual susceptibility). We also explored the proportion of urinary di-(2-ethylhexyl) phthalate (DEHP) metabolites contributed to by the bioactive mono-2-ethylhexyl phthalate (MEHP), considered a possible indicator of susceptibility to phthalate exposure. The percentage of phthalate metabolites present in the free form were less stable over time than the total metabolite concentration, and, therefore, it is not likely a useful indicator of metabolic susceptibility. Thus, the added costs and effort involved in the measurement of free in addition to total metabolite concentrations in large-scale studies may not be justified. Conversely, the proportion of DEHP metabolites contributed to by MEHP was more stable within individuals over time and may be a promising indicator of susceptibility if time of day of sample collection is carefully considered. PMID:22354176

  7. 75 FR 69662 - Workshop: Cumulative Mixtures Risk of Six Selected Phthalates in Support of Summary Information...

    Science.gov (United States)

    2010-11-15

    ... particular disruption of reproductive development in males and females; and (3) determine approaches to... Information System (IRIS) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Peer Consultation... phthalates are associated with adverse effects in male and female offspring; (2) determine how phthalates...

  8. NOVEL ORGANIZATION OF THE GENES FOR PHTHALATE DEGRADATION FROM BURKHOLDERIA CEPACIA DBO1

    Science.gov (United States)

    Burkholderia cepacia DBO1 is able to utilize phthalate as the sole source of carbon and energy for growth. Two overlapping cosmid clones containing the genes for phthalate degradation were isolated from this strain. Subcloning and activity analysis localized the genes for phthala...

  9. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  10. Phthalate esters in main source water and drinking water of Zhejiang Province (China): Distribution and health risks.

    Science.gov (United States)

    Wang, Xiaofeng; Lou, Xiaoming; Zhang, Nianhua; Ding, Gangqiang; Chen, Zhijian; Xu, Peiwei; Wu, Lizhi; Cai, Jianmin; Han, Jianlong; Qiu, Xueting

    2015-10-01

    To evaluate the distributions and health risks of phthalate esters in the main source water and corresponding drinking water of Zhejiang Province, the concentrations of 16 phthalate esters in water samples from 19 sites were measured from samples taken in the dry season and wet season. The concentration of the total phthalate ester congeners in source water ranged from 1.07 μg/L to 7.12 μg/L in the wet season, from 0.01 μg/L to 1.58 μg/L in the dry season, from 1.18 μg/L to 15.28 μg/L from drinking water in the wet season, and from 0.16 μg/L to 1.86 μg/L from drinking water in the dry season. Of the 16 phthalate esters, dimethyl phthalate, dibutyl phthalate, di-(2-ethyl-hexyl) phthalate, di-iso-butyl phthalate, bis-2-n-butoxyethyl phthalate, and dicyclohexyl phthalate were present in the samples analyzed, dominated by di-iso-butyl phthalate and di-(2-ethyl-hexyl) phthalate. The concentrations of phthalate esters in the wet season were all relatively higher than those in the dry season, and the drinking water had higher concentrations of phthalate esters than source water. The phthalate ester congeners studied pose little health risk to nearby citizens. Environ Toxicol Chem 2015;34:2205-2212. © 2015 SETAC. © 2015 SETAC.

  11. Phthalate exposure associated with self-reported diabetes among Mexican women

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Katherine [Graduate School of Public Health, Medical Sciences Campus, University of Puerto Rico, San Juan, PR (Puerto Rico); National Institute of Public Health, Universidad No. 655, Col. Santa Maria Ahuacatitlan, Cerrada los Pinos y Caminera, CP. 62100 Cuernavaca, Morelos (Mexico); Hernandez-Ramirez, Raul U.; Burguete-Garcia, Ana [National Institute of Public Health, Universidad No. 655, Col. Santa Maria Ahuacatitlan, Cerrada los Pinos y Caminera, CP. 62100 Cuernavaca, Morelos (Mexico); Cebrian, Mariano E. [Departamento de Toxicologia, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Mexico City (Mexico); Calafat, Antonia M.; Needham, Larry L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Claudio, Luz [Division of International Health, Department of Preventive Medicine, Mount Sinai School of Medicine, NY (United States); Lopez-Carrillo, Lizbeth, E-mail: lizbeth@insp.mx [National Institute of Public Health, Universidad No. 655, Col. Santa Maria Ahuacatitlan, Cerrada los Pinos y Caminera, CP. 62100 Cuernavaca, Morelos (Mexico)

    2011-08-15

    Background: Phthalates are ubiquitous industrial chemicals used as plasticizers in plastics made of polyvinyl chloride (PVC) to confer flexibility and durability. They are also present in products used for personal-care, industry and in medical devices. Phthalates have been associated with several adverse health effects, and recently it has been proposed that exposure to phthalates, could have an effect on metabolic homeostasis. This exploratory cross-sectional study evaluated the possible association between phthalate exposure and self-reported diabetes among adult Mexican women. Methods: As part of an on-going case-control study for breast cancer, only controls were selected, which constituted 221 healthy women matched by age ({+-}5 years) and place of residence with the cases. Women with diabetes were identified by self-report. Urinary concentrations of nine phthalate metabolites were measured by online solid phase extraction coupled to high performance liquid chromatography-isotope-dilution tandem mass spectrometry. Results: Participants with diabetes had significantly higher concentrations of di(2-ethylhexyl) pththalate (DEHP) metabolites: mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) but lower levels of monobenzyl phthalate (MBzP) a metabolite of benzylbutyl phthalate, compared to participants without diabetes. A marginally significant positive associations with diabetes status were observed over tertiles with MEHHP (OR{sub T3vs.T1}=2.66; 95% CI: 0.97-7.33; p for trend=0.063) and MEOHP (OR{sub T3vs.T1}=2.27; 95% CI; 0.90-5.75; P for trend=0.079) even after adjusting for important confounders. Conclusions: The results suggest that levels of some phthalates may play a role in the genesis of diabetes. - Highlights: {yields} This study evaluated phthalate exposure and diabetes status among Mexican women. {yields} Urinary phthalates metabolite concentrations were used

  12. Phthalate exposure associated with self-reported diabetes among Mexican women

    International Nuclear Information System (INIS)

    Svensson, Katherine; Hernandez-Ramirez, Raul U.; Burguete-Garcia, Ana; Cebrian, Mariano E.; Calafat, Antonia M.; Needham, Larry L.; Claudio, Luz; Lopez-Carrillo, Lizbeth

    2011-01-01

    Background: Phthalates are ubiquitous industrial chemicals used as plasticizers in plastics made of polyvinyl chloride (PVC) to confer flexibility and durability. They are also present in products used for personal-care, industry and in medical devices. Phthalates have been associated with several adverse health effects, and recently it has been proposed that exposure to phthalates, could have an effect on metabolic homeostasis. This exploratory cross-sectional study evaluated the possible association between phthalate exposure and self-reported diabetes among adult Mexican women. Methods: As part of an on-going case-control study for breast cancer, only controls were selected, which constituted 221 healthy women matched by age (±5 years) and place of residence with the cases. Women with diabetes were identified by self-report. Urinary concentrations of nine phthalate metabolites were measured by online solid phase extraction coupled to high performance liquid chromatography-isotope-dilution tandem mass spectrometry. Results: Participants with diabetes had significantly higher concentrations of di(2-ethylhexyl) pththalate (DEHP) metabolites: mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) but lower levels of monobenzyl phthalate (MBzP) a metabolite of benzylbutyl phthalate, compared to participants without diabetes. A marginally significant positive associations with diabetes status were observed over tertiles with MEHHP (OR T3vs.T1 =2.66; 95% CI: 0.97-7.33; p for trend=0.063) and MEOHP (OR T3vs.T1 =2.27; 95% CI; 0.90-5.75; P for trend=0.079) even after adjusting for important confounders. Conclusions: The results suggest that levels of some phthalates may play a role in the genesis of diabetes. - Highlights: → This study evaluated phthalate exposure and diabetes status among Mexican women. → Urinary phthalates metabolite concentrations were used to determine

  13. Influence of Phthalates on in vitro Innate and Adaptive Immune Responses

    DEFF Research Database (Denmark)

    Hansen, Juliana Frohnert; Nielsen, Claus Henrik; Brorson, Marianne Møller

    2015-01-01

    Phthalates are a group of endocrine disrupting chemicals, suspected to influence the immune system. The aim of this study was to investigate the influence of phthalates on cytokine secretion from human peripheral blood mononuclear cells. Escherichia coli lipopolysaccharide and phytohemagglutinin......-P were used for stimulation of monocytes/macrophages and T cells, respectively. Cells were exposed for 20 to 22 hours to either di-ethyl, di-n-butyl or mono-n-butyl phthalate at two different concentrations. Both diesters were metabolised to their respective monoester and influenced cytokine secretion......-α and interferon-γ by T cells. The investigated phthalate monoester also influenced cytokine secretion from monocytes/macrophages similar to that of the diesters. In T cells, however, the effect of the monoester was different compared to the diesters. The influence of the phthalates on the cytokine secretion did...

  14. Occurrence of phthalates in aquatic environment and their removal during wastewater treatment processes: a review.

    Science.gov (United States)

    Gani, Khalid Muzamil; Tyagi, Vinay Kumar; Kazmi, Absar Ahmad

    2017-07-01

    Phthalates are plasticizers and are concerned environmental endocrine-disrupting compounds. Due to their extensive usage in plastic manufacturing and personal care products as well as the potential to leach out from these products, phthalates have been detected in various aquatic environments including drinking water, groundwater, surface water, and wastewater. The primary source of their environmental occurrence is the discharge of phthalate-laden wastewater and sludge. This review focuses on recent knowledge on the occurrence of phthalate in different aquatic environments and their fate in conventional and advanced wastewater treatment processes. This review also summarizes recent advances in biological removal and degradation mechanisms of phthalates, identifies knowledge gaps, and suggests future research directions.

  15. Phthalates and food-contact materials: enforcing the 2008 European Union plastics legislation

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Jensen, Lisbeth Krüger

    2010-01-01

    Commission transformed the tolerable daily intakes established by the Authority into legislative limits for phthalates in both plastic and food simulants, while taking exposure from other sources into consideration. These limits have been into force since 1 July 2008. A detailed interpretation...... producers, FCM importers and importers of packed foodstuffs from third-party countries. Products containing phthalates above the current limits were found in several categories of FCM: conveyor belts (six of six), lids from packed foodstuffs in glasses (eight of 28), tubes for liquid foodstuffs (four...... of five) and gloves (five of 14). More than 20% of the samples analysed contained dibutylphthalate (DBP) or di-(2-ethylhexyl)phthalate (DEHP) above the compositional limits of 0.05% and 0.1%, respectively. Analysis of residual phthalates in metal lid gaskets instead of analysis of phthalates in the food...

  16. Enhancement of Ag-Based Plasmonic Photocatalysis in Hydrogen Production from Ammonia Borane by the Assistance of Single-Site Ti-Oxide Moieties within a Silica Framework.

    Science.gov (United States)

    Verma, Priyanka; Kuwahara, Yasutaka; Mori, Kohsuke; Yamashita, Hiromi

    2017-03-13

    Ag nanoparticles (NPs) have gained great attention owing to their interesting plasmonic properties and efficient catalysis under visible-light irradiation. In this study, an Ag-based plasmonic catalyst supported on mesoporous silica with isolated and tetrahedrally coordinated single-site Ti-oxide moieties, namely, Ag/Ti-SBA-15, was designed with the purpose of utilizing the broad spectral range of solar energy. The Ti-SBA-15 support allows the deposition of small Ag NPs with a narrow size distribution. The chemical structure, morphology, and optical properties of the prepared catalyst were characterized by techniques such as UV/Vis, FT extended X-ray absorption fine structure, and X-ray photoelectron spectroscopy, field-emission SEM, TEM, and N 2 physisorption studies. The catalytic activity of Ag/Ti-SBA-15 in hydrogen production from ammonia borane by hydrolysis was significantly enhanced in comparison with Ag/SBA-15 without Ti-oxide moieties and Ag/TiO 2 /SBA-15 involving agglomerated TiO 2 , both in the dark and under light irradiation. Improved electron transfer under light irradiation caused by the creation of heterojunctions between Ag NPs and Ti-oxide moieties explains the results obtained in the present study. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Ganoderma-Like MoS2 /NiS2 with Single Platinum Atoms Doping as an Efficient and Stable Hydrogen Evolution Reaction Catalyst.

    Science.gov (United States)

    Guan, Yongxin; Feng, Yangyang; Wan, Jing; Yang, Xiaohui; Fang, Ling; Gu, Xiao; Liu, Ruirui; Huang, Zhengyong; Li, Jian; Luo, Jun; Li, Changming; Wang, Yu

    2018-05-27

    Herein, a unique ganoderma-like MoS 2 /NiS 2 hetero-nanostructure with isolated Pt atoms anchored is reported. This novel ganoderma-like heterostructure can not only efficiently disperse and confine the few-layer MoS 2 nanosheets to fully expose the edge sites of MoS 2 , and provide more opportunity to capture the Pt atoms, but also tune the electronic structure to modify the catalytic activity. Because of the favorable dispersibility and exposed large specific surface area, single Pt atoms can be easily anchored on MoS 2 nanosheets with ultrahigh loading of 1.8 at% (the highest is 1.3 at% to date). Owing to the ganoderma-like structure and platinum atoms doping, this catalyst shows Pt-like catalytic activity for the hydrogen evolution reaction with an ultralow overpotential of 34 mV and excellent durability of only 2% increase in overpotential for 72 h under the constant current density of 10 mA cm -2 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A highly sensitive hydrogen sensor with gas selectivity using a PMMA membrane-coated Pd nanoparticle/single-layer graphene hybrid.

    Science.gov (United States)

    Hong, Juree; Lee, Sanggeun; Seo, Jungmok; Pyo, Soonjae; Kim, Jongbaeg; Lee, Taeyoon

    2015-02-18

    A polymer membrane-coated palladium (Pd) nanoparticle (NP)/single-layer graphene (SLG) hybrid sensor was fabricated for highly sensitive hydrogen gas (H2) sensing with gas selectivity. Pd NPs were deposited on SLG via the galvanic displacement reaction between graphene-buffered copper (Cu) and Pd ion. During the galvanic displacement reaction, graphene was used as a buffer layer, which transports electrons from Cu for Pd to nucleate on the SLG surface. The deposited Pd NPs on the SLG surface were well-distributed with high uniformity and low defects. The Pd NP/SLG hybrid was then coated with polymer membrane layer for the selective filtration of H2. Because of the selective H2 filtration effect of the polymer membrane layer, the sensor had no responses to methane, carbon monoxide, or nitrogen dioxide gas. On the contrary, the PMMA/Pd NP/SLG hybrid sensor exhibited a good response to exposure to 2% H2: on average, 66.37% response within 1.81 min and recovery within 5.52 min. In addition, reliable and repeatable sensing behaviors were obtained when the sensor was exposed to different H2 concentrations ranging from 0.025 to 2%.

  19. Determination of Phthalate Metabolites in Human Serum and Urine as Biomarkers for Phthalate Exposure Using Column-Switching LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Jee Yeon Jeong

    2011-03-01

    Conclusion:The accuracy and precision of the analytical method indicate that urinary metabolite determination can be a more acceptable biomarker for studying phthalate exposure and adverse health outcomes.

  20. Structural, mechanical, electrical and optical properties of a new lithium boro phthalate NLO crystal synthesized by a slow evaporation method

    Science.gov (United States)

    Mohanraj, K.; Balasubramanian, D.; Jhansi, N.

    2017-11-01

    A new non-linear optical (NLO) single crystal of lithium boro phthalate (LiBP) was grown by slow solvent evaporation technique. The powder sample was subjected to powder X-ray diffraction (PXRD) to find its crystalline nature and the crystal structure of the grown crystal was determined using single crystal X-ray (SXRD) diffraction analysis. The Fourier Transform Infrared (FTIR) spectrum was recorded for grown crystal to identify the various functional groups present in the compound. The mechanical property of the LiBP single crystal was studied using Vickers microhardness tester. The dielectric constant and dielectric loss measurements were carried out for the grown crystal at various temperatures. The grown crystal was subjected to UV-Visible Spectral Studies to analyze the linear optical behavior of the grown crystal. The Kurtz-Perry Powder technique was employed to measure the Second Harmonic Generation efficiency of the grown crystal.

  1. Temporal variability in urinary phthalate metabolite excretion based on spot, morning, and 24-h urine samples: Considerations for epidemiological studies

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Kranich, Selma K.; Jørgensen, Niels

    2013-01-01

    of exposures for these two phthalates in population studies and hence an attenuation of the power to detect possible exposure-outcome associations. The only slightly higher ICCs for 24-h pools compared to first-morning and spot urine samples does not seem to justify the extra effort needed to collect 24-h......Urinary phthalate excretion is used as marker of phthalate exposure in epidemiological studies. Here we examine the reliability of urinary phthalate levels in exposure classification by comparing the inter- and intrasubject variation of urinary phthalate metabolite levels. Thirty-three young...

  2. Hydrogen system (hydrogen fuels feasibility)

    International Nuclear Information System (INIS)

    Guarna, S.

    1991-07-01

    This feasibility study on the production and use of hydrogen fuels for industry and domestic purposes includes the following aspects: physical and chemical properties of hydrogen; production methods steam reforming of natural gas, hydrolysis of water; liquid and gaseous hydrogen transportation and storage (hydrogen-hydride technology); environmental impacts, safety and economics of hydrogen fuel cells for power generation and hydrogen automotive fuels; relevant international research programs

  3. Impact of di-n-butyl phthalate on reproductive system development in European pikeperch (Sander lucioperca

    Directory of Open Access Journals (Sweden)

    Sylwia Jarmołowicz

    2013-01-01

    Full Text Available Phthalic acid, di-n-butyl ester known as di-n-butyl phthalate, is an organic chemical compound that belongs to the group of endocrine disruptor compounds that have a documented negative impact on mammalian endocrine systems. Di-n-butyl phthalate is used widely as a plasticizer in the manufacture of artificial materials, which is why it is found in all types of environmental samples including those from water basins. The aim of the study was to describe the impact of di-n-butyl phthalate on the development of the reproductive system of European pikeperch (Sander lucioperca during the sex differentiation period (age 61–96 days post hatch. A total of 240 fish were divided into 6 groups (40 fish per tank. Treatments consisted of a control group (0 g di-n-butyl phthalate·kg-1 feed and five trial groups with 0.125, 0.25, 0.5, 1, and 2 g di-n-butyl phthalate·kg-1 feed, respectively. Histological changes of the fish gonads, sex ratio, survival and growth of fish were evaluated. Di-n-butyl phthalate seriously disturbed sex differentiation process of pikeperch. Histopathological analyses revealed that the administration of 2 g di-n-butyl phthalate·kg-1 significantly affected the sex ratio. The feminization process (intersex gonads at concentrations of 1 g and 2 g di-n-butyl phthalate·kg-1 were observed. All analyzed concentrations delayed testicular development. Phthalate did not have a significant impact on the survival or growth rates of the pikeperch. This is the first report of disruption sex differentiation processes in fish by di-n-butyl phthalate.

  4. Evaluation of method for phthalate extraction from milk related to milk dilution ratio

    Directory of Open Access Journals (Sweden)

    Milojković Danica S.

    2015-01-01

    Full Text Available Liquid-liquid extraction techniques were compared coupled with gas chromatography-mass spectrometry (GC-MS, for the extraction and the determination of four phthalates: dimethyl phthalate (DMP, di-n-butyl phthalate (DBP, benzyl butyl phthalate (BBP and di-(2-ethylhexyl phthalate (DEHP in six different kinds of milk-based samples. Extraction factors: sample preparation, organic solvent type and volume, salt effect, agitation and the extraction time were optimized. The ion of base peaks (m/z 149 for DBP, BBP and DEHP and m/z 163 for DMP for investigated phthalates were selected for the screening studies. The acquisition was performed at the selected ion monitoring mode. The MSD response for GC-MS phthalate calibration standards was linear between 0.25 and 2.50 μg mL-1 with calculated LODs between 0.01 μg mL-1 to 0.04 μg mL-1 and LOQs of 0.05 μg mL-1 to 0.12 μg mL-1, while repeatability was between 1.7 % to 4.9 % RSD. The study demonstrated an increase of the recovery of less polar phthalates in matrix milk standards by matrix dilution. Recovery for hydrophilic phthalates, like DMP, was not changed by matrix dilution and it was continuously low for the investigated method. Two spiking levels were tested for influence of matrix dilution on phthalate recovery, showed the same trend. [Projekat Ministarstva nauke Republike Srbije, br. 31060

  5. Exposure to phthalates: reproductive outcome and children health. A review of epidemiological studies.

    Science.gov (United States)

    Jurewicz, Joanna; Hanke, Wojciech

    2011-06-01

    Phthalates are a family of industrial chemicals that have been used for a variety of purposes. As the potential consequences of human exposure to phthalates have raised concerns in the general population, they have been studied in susceptible subjects such as pregnant women, infants and children. This article aims at evaluating the impact of exposure to phthalates on reproductive outcomes and children health by reviewing most recent published literature. Epidemiological studies focusing on exposure to phthalates and pregnancy outcome, genital development, semen quality, precocious puberty, thyroid function, respiratory symptoms and neurodevelopment in children for the last ten years were identified by a search of the PubMed, Medline, Ebsco, Agricola and Toxnet literature bases. The results from the presented studies suggest that there are strong and rather consistent indications that phthalates increase the risk of allergy and asthma and have an adverse impact on children's neurodevelopment reflected by quality of alertness among girls, decreased (less masculine) composite score in boys and attention deficit hyperactivity disorder. Results of few studies demonstrate negative associations between phthalate levels commonly experienced by the public and impaired sperm quality (concentration, morphology, motility). Phthalates negatively impact also on gestational age and head circumference; however, the results of the studies were not consistent. In all the reviewed studies, exposure to phthalates adversely affected the level of reproductive hormones (luteinizing hormone, free testosterone, sex hormone-binding globulin), anogenital distance and thyroid function. The urinary levels of phthalates were significantly higher in the pubertal gynecomastia group, in serum in girls with premature thelarche and in girls with precocious puberty. Epidemiological studies, in spite of their limitations, suggest that phthalates may affect reproductive outcome and children health

  6. Regulation of mRNA Translation Is a Novel Mechanism for Phthalate Toxicity.

    Directory of Open Access Journals (Sweden)

    Jun Ling

    Full Text Available Phthalates are a group of plasticizers that are widely used in many consumer products and medical devices, thus generating a huge burden to human health. Phthalates have been known to cause a number of developmental and reproductive disorders functioning as endocrine modulators. They are also involved in carcinogenesis with mechanisms less understood. To further understand the molecular mechanisms of phthalate toxicity, in this study we reported a new effect of phthalates on mRNA translation/protein synthesis, a key regulatory step of gene expression. Butyl benzyl phthalate (BBP was found to directly inhibit mRNA translation in vitro but showed a complicated pattern of affecting mRNA translation in cells. In human kidney embryonic cell (HEK-293T, BBP increased cap-dependent mRNA translation at lower concentrations but showed inhibitory effect at higher concentrations. Cap-independent translation was not affected. On the other hand, mono (2-ethylhexyl phthalate (MEHP as a major metabolite of another important phthalate di (2-ethylhexyl phthalate (DEHP inhibited both can-dependent and -independent mRNA translation in vivo. In contrast, BBP and MEHP exhibited an overall promoting effect on mRNA translation in cancer cells. Mechanistic studies identified that the level and phosphorylation of eIF4E-BP (eIF4E binding protein and the amount of eIF4GI in eIF4F complex were altered in accordance with the effect of BBP on translation. BBP was also identified to directly bind to eIF4E, providing a further mechanism underlying the regulation of mRNA by phthalate. At the cellular level BBP inhibited normal cell growth but slightly promoted cancer cells (HT29 growth. Overall, this study provides the first evidence that phthalates can directly regulate mRNA translation as a novel mechanism to mediate their biological toxicities.

  7. Relationship between environmental phthalate exposure and the intelligence of school-age children.

    Science.gov (United States)

    Cho, Soo-Churl; Bhang, Soo-Young; Hong, Yun-Chul; Shin, Min-Sup; Kim, Boong-Nyun; Kim, Jae-Won; Yoo, Hee-Jung; Cho, In Hee; Kim, Hyo-Won

    2010-07-01

    Concern over phthalates has emerged because of their potential toxicity to humans. We investigated the relationship between the urinary concentrations of phthalate metabolites and children's intellectual functioning. This study enrolled 667 children at nine elementary schools in five South Korean cities. A cross-sectional examination of urine phthalate concentrations was performed, and scores on neuropsychological tests were obtained from both the children and their mothers. We measured mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-oxohexyl)phthalate (MEOHP), both metabolites of di(2-ethylhexyl)phthalate (DEHP), and mono-n-butyl phthalate (MBP), a metabolite of dibutyl phthalate (DBP), in urine samples. The geometric mean (ln) concentrations of MEHP, MEOHP, and MBP were 21.3 microg/L [geometric SD (GSD) = 2.2 microg/L; range, 0.5-445.4], 18.0 microg/L (GSD = 2.4; range, 0.07-291.1), and 48.9 microg/L (GSD = 2.2; range, 2.1-1645.5), respectively. After adjusting for demographic and developmental covariates, the Full Scale IQ and Verbal IQ scores were negatively associated with DEHP metabolites but not with DBP metabolites. We also found a significant negative relationship between the urine concentrations of the metabolites of DEHP and DBP and children's vocabulary subscores. After controlling for maternal IQ, a significant inverse relationship between DEHP metabolites and vocabulary subscale score remained. Among boys, we found a negative association between increasing MEHP phthalate concentrations and the sum of DEHP metabolite concentrations and Wechsler Intelligence Scale for Children vocabulary score; however, among girls, we found no significant association between these variables. Controlling for maternal IQ and other covariates, the results show an inverse relationship between phthalate metabolites and IQ scores; however, given the limitations in cross-sectional epidemiology, prospective studies are needed to fully explore these associations.

  8. Prenatal phthalate exposures and child temperament at 12 and 24 months.

    Science.gov (United States)

    Singer, Alison B; Wolff, Mary S; Silva, Manori J; Calafat, Antonia M; Engel, Stephanie M

    2017-09-01

    Gestational phthalate exposures have been adversely associated with attention, externalizing, and internalizing behaviors in childhood. Early childhood temperament may be a marker of later behavioral patterns. We therefore sought to determine whether gestational phthalate exposures were associated with infant and toddler temperament. The Mount Sinai Children's Environmental Health Study is a prospective cohort study of children born between May 1998 and July 2001 in New York City (N=404). Phthalate metabolites were measured in spot urine samples collected from pregnant women in their third trimester. Child temperament was assessed by parental report at 12-months using the Infant Behavior Questionnaire (IBQ) (N=204) and at 24-months using the Toddler Behavior Assessment Questionnaire (TBAQ) (N=279). We used multiple linear regression to evaluate associations between urinary phthalate metabolites and eleven temperament domains. Phthalate biomarker concentrations were weakly associated with lower gross motor activity levels as well as higher duration of orienting at the 12-month assessment. Mono(3-carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP) and the sum of metabolites of di(2-ethylhexyl) phthalate (∑DEHP) were associated with lower levels of smiling and laughing at 12 months. At 24-months, social fear and lower pleasure was linked to higher concentrations of MCPP and MBzP, and higher ∑DEHP was weakly associated with increased anger levels at 24-months. Though we observed some weak associations between biomarkers of prenatal exposure to phthalates and temperament at 12- and 24-months, overall phthalates biomarkers were not strongly associated with alterations in temperament. Copyright © 2017. Published by Elsevier B.V.

  9. Prenatal Phthalate Exposures and Childhood Fat Mass in a New York City Cohort.

    Science.gov (United States)

    Buckley, Jessie P; Engel, Stephanie M; Mendez, Michelle A; Richardson, David B; Daniels, Julie L; Calafat, Antonia M; Wolff, Mary S; Herring, Amy H

    2016-04-01

    Experimental animal studies and limited epidemiologic evidence suggest that prenatal exposure to phthalates may be obesogenic, with potential sex-specific effects of phthalates having anti-androgenic activity. We aimed to assess associations between prenatal phthalate exposures and childhood fat mass in a prospective cohort study. We measured phthalate metabolite concentrations in third-trimester maternal urine in a cohort of women enrolled in New York City between 1998 and 2002 (n = 404). Among 180 children (82 girls and 98 boys), we evaluated body composition using a Tanita scale at multiple follow-up visits between ages 4 and 9 years (363 total visits). We estimated associations of standard deviation differences or tertiles of natural log phthalate metabolite concentrations with percent fat mass using linear mixed-effects regression models with random intercepts for repeated outcome measurements. We assessed associations in multiple metabolite models and adjusted for covariates including prepregnancy body mass index, gestational weight gain, maternal smoking during pregnancy, and breastfeeding. We did not observe associations between maternal urinary phthalate concentrations and percent body fat in models examining continuous exposures. Fat mass was 3.06% (95% CI: -5.99, -0.09%) lower among children in the highest tertile of maternal urinary concentrations of summed di(2-ethylhexyl) phthalate (ΣDEHP) metabolites than in children in the lowest tertile. Though estimates were imprecise, there was little evidence that associations between maternal urinary phthalate concentrations and percent fat mass were modified by child's sex. Prenatal phthalate exposures were not associated with increased body fat among children 4-9 years of age, though high prenatal DEHP exposure may be associated with lower fat mass in childhood. Buckley JP, Engel SM, Mendez MA, Richardson DB, Daniels JL, Calafat AM, Wolff MS, Herring AH. 2016. Prenatal phthalate exposures and childhood fat

  10. Within-person reproducibility of urinary bisphenol A and phthalate metabolites over a 1 to 3 year period among women in the Nurses’ Health Studies: a prospective cohort study

    Science.gov (United States)

    2013-01-01

    Background Associations of bisphenol A and phthalates with chronic disease health outcomes are increasingly being investigated in epidemiologic studies. The majority of previous studies of within-person variability in urinary bisphenol A and phthalate metabolite concentrations have focused on reproducibility over short time periods. Long-term reproducibility data are needed to assess the potential usefulness of these biomarkers for prospective studies, particularly those examining risk of diseases with long latency periods. Low within-person reproducibility may attenuate relative risk estimates and reduce statistical power to detect associations with disease. Therefore, we assessed within-person reproducibility of bisphenol A, eight phthalate metabolites, and phthalic acid in spot urine samples over 1 to 3 years among women enrolled in two large cohort studies. Methods Women in the Nurses’ Health Study and Nurses’ Health Study II provided two spot urine samples, 1 to 3 years apart (n = 80 women for analyses of bisphenol A; n = 40 women for analyses of phthalate metabolites; n = 34 women for analyses of phthalic acid). To measure within-person reproducibility, we calculated Spearman rank correlation coefficients and intraclass correlation coefficients for creatinine-adjusted concentrations of bisphenol A, phthalate metabolites, and phthalic acid. Results Over 1 to 3 years, within-person variability of bisphenol A was high relative to total variability (intraclass correlation coefficient = 0.14) and rankings of bisphenol A levels between time-points were weakly correlated (Spearman correlation = 0.19). Seven of the eight phthalate metabolites and phthalic acid demonstrated moderate within-person stability over time (Spearman correlation or intraclass correlation coefficient = 0.39-0.55). Restricting analyses to first-morning urine samples did not alter results. Conclusions Single measurements of bisphenol A in spot urine samples were

  11. Within-person reproducibility of urinary bisphenol A and phthalate metabolites over a 1 to 3 year period among women in the Nurses' Health Studies: a prospective cohort study.

    Science.gov (United States)

    Townsend, Mary K; Franke, Adrian A; Li, Xingnan; Hu, Frank B; Eliassen, A Heather

    2013-09-13

    Associations of bisphenol A and phthalates with chronic disease health outcomes are increasingly being investigated in epidemiologic studies. The majority of previous studies of within-person variability in urinary bisphenol A and phthalate metabolite concentrations have focused on reproducibility over short time periods. Long-term reproducibility data are needed to assess the potential usefulness of these biomarkers for prospective studies, particularly those examining risk of diseases with long latency periods. Low within-person reproducibility may attenuate relative risk estimates and reduce statistical power to detect associations with disease. Therefore, we assessed within-person reproducibility of bisphenol A, eight phthalate metabolites, and phthalic acid in spot urine samples over 1 to 3 years among women enrolled in two large cohort studies. Women in the Nurses' Health Study and Nurses' Health Study II provided two spot urine samples, 1 to 3 years apart (n = 80 women for analyses of bisphenol A; n = 40 women for analyses of phthalate metabolites; n = 34 women for analyses of phthalic acid). To measure within-person reproducibility, we calculated Spearman rank correlation coefficients and intraclass correlation coefficients for creatinine-adjusted concentrations of bisphenol A, phthalate metabolites, and phthalic acid. Over 1 to 3 years, within-person variability of bisphenol A was high relative to total variability (intraclass correlation coefficient = 0.14) and rankings of bisphenol A levels between time-points were weakly correlated (Spearman correlation = 0.19). Seven of the eight phthalate metabolites and phthalic acid demonstrated moderate within-person stability over time (Spearman correlation or intraclass correlation coefficient = 0.39-0.55). Restricting analyses to first-morning urine samples did not alter results. Single measurements of bisphenol A in spot urine samples were highly variable within women over 1 to 3

  12. Phthalates Are Metabolised by Primary Thyroid Cell Cultures but Have Limited Influence on Selected Thyroid Cell Functions In Vitro.

    Directory of Open Access Journals (Sweden)

    Juliana Frohnert Hansen

    Full Text Available Phthalates are plasticisers added to a wide variety of products, resulting in measurable exposure of humans. They are suspected to disrupt the thyroid axis as epidemiological studies suggest an influence on the peripheral thyroid hormone concentration. The mechanism is still unknown as only few in vitro studies within this area exist. The aim of the present study was to investigate the influence of three phthalate diesters (di-ethyl phthalate, di-n-butyl phthalate (DnBP, di-(2-ethylhexyl phthalate (DEHP and two monoesters (mono-n-butyl phthalate and mono-(2-ethylhexyl phthalate (MEHP on the differentiated function of primary human thyroid cell cultures. Also, the kinetics of phthalate metabolism were investigated. DEHP and its monoester, MEHP, both had an inhibitory influence on 3'-5'-cyclic adenosine monophosphate secretion from the cells, and MEHP also on thyroglobulin (Tg secretion from the cells. Results of the lactate dehydrogenase-measurements indicated that the MEHP-mediated influence was caused by cell death. No influence on gene expression of thyroid specific genes (Tg, thyroid peroxidase, sodium iodine symporter and thyroid stimulating hormone receptor by any of the investigated diesters could be demonstrated. All phthalate diesters were metabolised to the respective monoester, however with a fall in efficiency for high concentrations of the larger diesters DnBP and DEHP. In conclusion, human thyroid cells were able to metabolise phthalates but this phthalate-exposure did not appear to substantially influence selected functions of these cells.

  13. Determination of phthalates released from paper packaging materials by solid-phase extraction-high-performance liquid chromatography.

    Science.gov (United States)

    Gao, Xin; Yang, Bofeng; Tang, Zhixu; Luo, Xin; Wang, Fengmei; Xu, Hui; Cai, Xue

    2014-01-01

    A solid phase extraction (SPE) high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of 10 phthalic acid esters (dimethyl phthalate, diethyl phthalate, dipropyl phthalate, benzylbutyl phthalate, diisobutyl phthalate, dicyclohexyl phthalate, diamyl phthalate, di-n-hexyl phthalate, di-n-octyl phthalate and di-2-ethylhexyl phthalate) released from food paper packaging materials. The use of distilled water, 3% acetic acid (w/v), 10% ethanol (v/v) and 95% ethanol (v/v) instead of the different types of food simulated the migration of 10 phthalic acid esters from food paper packaging materials; the phthalic acid esters in four food simulants were enriched and purified by a C18 SPE column and nitrogen blowing, and quantified by HPLC with a diode array detector. The chromatographic conditions and extraction conditions were optimized and all 10 of the phthalate acid esters had a maximum absorbance at 224 nm. The method showed limitations of detection in the range of 6.0-23.8 ng/mL the correlation coefficients were greater than 0.9999 in all cases, recovery values ranged between 71.27 and 106.97% at spiking levels of 30, 60 and 90 ng/mL and relative standard deviation values ranged from 0.86 to 8.00%. The method was considered to be simple, fast and reliable for a study on the migration of these 10 phthalic acid esters from food paper packaging materials into food.

  14. Contamination level of four priority phthalates in North Indian wastewater treatment plants and their fate in sequencing batch reactor systems.

    Science.gov (United States)

    Gani, Khalid Muzamil; Rajpal, Ankur; Kazmi, Absar Ahmad

    2016-03-01

    The contamination level of four phthalates in untreated and treated wastewater of fifteen wastewater treatment plants (WWTPs) and their fate in a full scale sequencing batch reactor (SBR) based WWTP was evaluated in this study. The four phthalates were diethyl phthalate (DEP), dibutyl phthalate (DBP), benzylbutyl phthalate (BBP) and diethylhexyl phthalate (DEHP). All compounds were present in untreated wastewater with DEHP being present in the highest mean concentration of 28.4 ± 5.3 μg L(-1). The concentration was in the range of 7.3 μg L(-1) (BBP) to 28.4 μg L(-1) (DEHP) in untreated wastewater and 1.3 μg L(-1) (DBP) to 2.6 μg L(-1) (DEHP) in treated wastewater. The nutrient removal process and advance tertiary treatment based WWTPs showed the highest phthalate removal efficiencies of 87% and 93%, respectively. The correlation between phthalate removal and conventional performance of WWTPs was positive. Fate analysis of these phthalates in a SBR based WWTP showed that total removal of the sum of phthalates in a primary settling tank and SBR was 84% out of which 55% is removed by biodegradation and 29% was removed by sorption to primary and secondary sludge. The percentage removal of four phthalates in primary settling tanks was 18%. Comparison of the diluted effluent DEHP concentration with its environmental quality standards showed that the dilution in an effluent receiving water body can reduce the DEHP emissions to acceptable values.

  15. The association between phthalate exposure and atopic dermatitis with a discussion of phthalate induced secretion of interleukin-1β and thymic stromal lymphopoietin.

    Science.gov (United States)

    Overgaard, Line E K; Bonefeld, Charlotte M; Frederiksen, Hanne; Main, Katharina M; Thyssen, Jacob P

    2016-06-01

    Phthalate diesters are widely used as emollients in plastic and cosmetics as well as in food packaging and perfumes, potentially leading to prolonged and repeated dermal, oral and airborne exposure. We here review published articles that have evaluated the putative role of phthalate diesters in the pathogenesis of atopic dermatitis and discuss possible pathogenic pathways. A literature search resulted in 563 articles in Embase and 263 articles in Pubmed. After identification of relevant articles based on screening of titles, abstracts and reference lists, a total of 39 articles were selected and included. While no clear association has been shown between systemic phthalate levels and atopic dermatitis in human studies, animal data suggests that phthalates may worsen dermatitis and in vitro data suggests that interleukin-4 could be upregulated. Moreover, both loss-of-function mutations in the filaggrin gene and atopic dermatitis have been associated with elevated systemic phthalate levels. There is a need for prospective studies to clarify the possible pathogenic role of phthalate diesters in atopic dermatitis and the associated health risk, especially with the general trend towards barrier restoration with emollients in infants at risk of developing atopic dermatitis. In summary, we conclude that the results from published studies are controversial and inconclusive.

  16. Considerations on ultra-trace analysis of phthalates in drinking water.

    Science.gov (United States)

    Serôdio, P; Nogueira, J M F

    2006-07-01

    Stir bar sorptive extraction with liquid desorption followed by large volume injection and capillary gas chromatography coupled to mass spectrometry (SBSE-LD/LVI-GC-MS), had been applied for the determination of ultra-traces of seven-phthalates (dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate) in drinking water samples, which are included in the priority lists set by several international regulatory organizations. Instrumental calibration under the selected-ion monitoring mode acquisition (LVI-GC-MS(SIM)), experimental parameters that could affect the SBSE-LD efficiency, as well as, the control of the contamination profile are fully discussed. Throughout systematic assays on 30 mL water samples spiked at the 0.40 microg/L level, it had been established that stir bars coated with 47 microL of polydimethylsiloxane, an equilibrium time of 60 min (1,000 rpm) and methanol as back extraction solvent, allowed the best analytical performance to monitor phthalates in water matrices. From the data obtained, good accuracy and a remarkable reproducibility (water partition coefficients (K(PDMS/W) approximately K(O/W)), with the exception of bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate, for which lower yields were measured. Additionally, a remarkable linear dynamic range between 25 and 2,000 ng/L (r(2)>0.99) and low detection limits (3-40 ng/L) were also achieved for the seven-phthalates studied. The application of the present method to monitor phthalates in tap and bottled mineral water samples, allowed convenient selectivity and high sensitivity up to 1.0 microg/L level, using the standard addition methodology. The proposed method showed to be feasible and sensitive with a low sample volume requirement to monitor phthalates in drinking water matrices at the ultra-trace level, in compliance with international regulatory

  17. Hail hydrogen

    International Nuclear Information System (INIS)

    Hairston, D.

    1996-01-01

    After years of being scorned and maligned, hydrogen is finding favor in environmental and process applications. There is enormous demand for the industrial gas from petroleum refiners, who need in creasing amounts of hydrogen to remove sulfur and other contaminants from crude oil. In pulp and paper mills, hydrogen is turning up as hydrogen peroxide, displacing bleaching agents based on chlorine. Now, new technologies for making hydrogen have the industry abuzz. With better capabilities of being generated onsite at higher purity levels, recycled and reused, hydrogen is being prepped for a range of applications, from waste reduction to purification of Nylon 6 and hydrogenation of specialty chemicals. The paper discusses the strong market demand for hydrogen, easier routes being developed for hydrogen production, and the use of hydrogen in the future

  18. Growth and spectroscopic, thermodynamic and nonlinear optical studies of L-threonine phthalate crystal

    Science.gov (United States)

    Theras, J. Elberin Mary; Kalaivani, D.; Jayaraman, D.; Joseph, V.

    2015-10-01

    L-threonine phthalate (LTP) single crystal has been grown using a solution growth technique at room temperature. Single crystal X-ray diffraction analysis reveals that LTP crystallizes in monoclinic crystal system with space group C2/c. The optical absorption studies show that the crystal is transparent in the entire visible region with a cut-off wavelength 309 nm. The optical band gap is found to be 4.05 eV. The functional groups of the synthesized compound have been identified by FTIR spectral analysis. The functional groups present in the material were also confirmed by FT-RAMAN spectroscopy. Surface morphology and the presence of various elements were studied by SEM-EDAX analysis. The thermal stability of LTP single crystal has been analyzed by TGA/DTA studies. The thermodynamic parameters such as activation energy, entropy, enthalpy and Gibbs free energy were determined for the grown material using TG data and Coats-Redfern relation. Since the grown crystal is centrosymmetric, Z-Scan studies were carried out for analyzing the third order nonlinear optical property. The nonlinear absorption coefficient, nonlinear refractive index and susceptibility have been measured using Z-Scan technique.

  19. Phthalate Migration Study from PVC Grafted by Gamma Radiation

    International Nuclear Information System (INIS)

    Manzoli, J.E.; Duarte, C.; Somesari, E.; Silveira, C.; Paes, H.A.; Manzoli, J.E.; Araujo, F.D.C.; Panzarini, L.C.G.A.

    2009-01-01

    PVC is a useful polymer used for many applications, as packaging of food, blood and in contact with body fluids. The most widely-used plasticizer, to make it flexible, is the phthalate DEHP, and its toxicity is a problem. A special radiation grafting of PVC allows an important reduction of thrombogenic properties, and it could cause changes in the DEHP migration too. In this work it is presented the methodology using gas chromatography and numerical simulation for the measurement of DEHP migration from PVC grafted with monomer DMAEMA. The grafting could be an interesting way to reduce DEHP migration

  20. Rapid and sensitive analysis of phthalate metabolites, bisphenol A, and endogenous steroid hormones in human urine by mixed-mode solid-phase extraction, dansylation, and ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry.

    Science.gov (United States)

    Wang, He-xing; Wang, Bin; Zhou, Ying; Jiang, Qing-wu

    2013-05-01

    Steroid hormone levels in human urine are convenient and sensitive indicators for the impact of phthalates and/or bisphenol A (BPA) exposure on the human steroid hormone endocrine system. In this study, a rapid and sensitive method for determination of 14 phthalate metabolites, BPA, and ten endogenous steroid hormones in urine was developed and validated on the basis of ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry. The optimized mixed-mode solid phase-extraction separated the weakly acidic or neutral BPA and steroid hormones from acidic phthalate metabolites in urine: the former were determined in positive ion mode with a methanol/water mobile phase containing 10 mM ammonium formate; the latter were determined in negative ion mode with a acetonitrile/water mobile phase containing 0.1 % acetic acid, which significantly alleviated matrix effects for the analysis of BPA and steroid hormones. Dansylation of estrogens and BPA realized simultaneous and sensitive analysis of the endogenous steroid hormones and BPA in a single chromatographic run. The limits of detection were less than 0.84 ng/mL for phthalate metabolites and less than 0.22 ng/mL for endogenous steroid hormones and BPA. This proposed method had satisfactory precision and accuracy, and was successfully applied to the analyses of human urine samples. This method could be valuable when investigating the associations among endocrine-disrupting chemicals, endogenous steroid hormones, and relevant adverse outcomes in epidemiological studies.

  1. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)

    2016-01-21

    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  2. Oxidation behavior of stainless steel 430 and 441 at 800 C in single (air/air) and dual atmosphere (air/hydrogen) exposures

    Energy Technology Data Exchange (ETDEWEB)

    Rufner, J.; Gannon, P.; White, P.; Deibert, M.; Teintze, S. [Chemical and Biological Engineering, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59717-3920 (United States); Smith, R.; Chen, H. [Physics, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59717-3920 (United States)

    2008-02-15

    Intermediate temperature ({proportional_to}800 {sup o}C) planar solid oxide fuel cells (SOFCs) allow the use of ferritic stainless steel (FSS) interconnects. SOFC FSS interconnects are used to stack individual cells into series, and are simultaneously exposed to air on the cathode side and fuel on the anode side, creating a 'dual atmosphere' exposure. The thermally grown oxide (TGO) layers on the air side of FSSs 430 and 441 were analyzed as a function of simulated dual atmosphere exposures (moist air/moist hydrogen) for up to 300 h. FSS 430 showed some changes in oxidation behavior, with a slight Fe concentration increase and localized Fe{sub 2}O{sub 3} nodule formation observed in the dual atmosphere TGO layer relative to its single atmosphere (air/air) counterpart. Significantly accelerated and anomalous oxidation was observed with FSS 441 subjected to dual atmosphere exposures compared with air/air exposures. The TGO layer formed on the 441 exposed to air/air was comprised of Mn-rich, Cr and Fe-containing isomorphic spinel surface crystallites, with a Cr{sub 2}O{sub 3} (eskolaite)-based bottom layer, having a total TGO layer thickness of <2{mu} m after 300 h. In contrast, the TGO layer formed on 441 during dual atmosphere exposure was much faster-growing (>6{mu} m in 20 h) and exhibited a continuous, porous Fe{sub 2}O{sub 3}-rich surface layer with a relatively thin (<2{mu} m) sublayer of similar composition to the TGO layer formed during the air/air exposure. Spontaneous TGO layer spallation was also observed for the air side of 441 exposed to dual atmosphere for >100h. The observed oxidation behavior and TGO layer evolution of 441 in both air/air and dual atmosphere are presented, with possible mechanisms and implications discussed. (author)

  3. Exposure to phthalates in house dust and associated allergies in children aged 6-12years.

    Science.gov (United States)

    Ait Bamai, Yu; Araki, Atsuko; Kawai, Toshio; Tsuboi, Tazuru; Saito, Ikue; Yoshioka, Eiji; Cong, Shi; Kishi, Reiko

    2016-11-01

    Phthalates are widely used as plasticizers in household products. Several studies have reported an association between phthalate exposure and an increased risk of allergies. The present study estimated phthalate exposure in children aged 6-12years and assessed potential correlations with allergies. House dust samples were collected from floors and multi-surface objects >35cm above the floor. Urine samples were collected from the first morning void of the day. Daily phthalate intake (DI dust and DI) was estimated using both house dust and urinary metabolite concentrations. Exposure to di-2-ethylhexyl phthalate (DEHP) in floor dust was associated with parental-reported rhino-conjunctivitis. After stratification by gender, this trend was found to only occur in boys. Furthermore, urinary mono-isobutyl phthalate was inversely associated with parental-reported wheeze in boys. DI dust of benzyl butyl phthalate (BBzP) and DEHP were significantly correlated with DI_BBzP and DI_DEHP, respectively. These correlations were stronger with floor than with multi-surface dust. Our results suggest that, among Japanese children, house dust from low surfaces, such as living room floors, might play a meaningful role in the indoor environmental exposure pathway for BBzP and DEHP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Dietary Phthalate Exposure in Pregnant Women and the Impact of Consumer Practices

    Directory of Open Access Journals (Sweden)

    Samantha E. Serrano

    2014-06-01

    Full Text Available Phthalates are ubiquitous endocrine-disrupting chemicals that are contaminants in food and contribute to significant dietary exposures. We examined associations between reported consumption of specific foods and beverages and first trimester urinary phthalate metabolite concentrations in 656 pregnant women within a multicenter cohort study, The Infant Development and Environment Study (TIDES, using multivariate regression analysis. We also examined whether reported use of ecofriendly and chemical-free products was associated with lower phthalate biomarker levels in comparison to not following such practices. Consumption of one additional serving of dairy per week was associated with decreases of 1% in the sum of di-2-ethylhexyl phthalate (DEHP metabolite levels (95% CI: −2.0, −0.2. Further, participants who reported sometimes eating homegrown food had monoisobutyl phthalate (MiBP levels that were 16.6% lower (95% CI: −29.5, −1.3 in comparison to participants in the rarely/never category. In contrast to rarely/never eating frozen fruits and vegetables, participants who reported sometimes following this practice had monobenzyl phthalate (MBzP levels that were 21% higher (95% CI: 3.3, 41.7 than rarely/ever respondents. Future study on prenatal dietary phthalate exposure and the role of consumer product choices in reducing such exposure is needed.

  5. Association between Phthalate Exposure and the Use of Plastic Containers in Shanghai Adults.

    Science.gov (United States)

    Dong, Rui Hua; Zhang, Han; Zhang, Mei Ru; Chen, Jing Si; Wu, Min; Li, Shu Guang; Chen, Bo

    2017-10-01

    Consuming phthalates may be due to the presence of food contact materials, such as plastic containers. In this study, we investigated the association between plastic container use and phthalate exposure in 2,140 Shanghai adults. Participants completed a questionnaire on the frequency of using plastic containers in different scenarios in the previous year (e.g., daily, weekly) and on the consumption of plastic-packaged foods in the previous three days (yes or no). Urinary phthalate metabolites were used to assess the association between phthalate exposure and the use of plastic containers. The metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the most frequently detected in urine. The results revealed that phthalate exposure was associated with consumption of plastic-packaged breakfast or processed food items in the previous three days. The consumption of these two food items had strong synergistic effects on increasing urinary concentrations of most phthalate metabolites. Our results of plastic-packaged breakfast and processed food may be explained by the use of flexible plastic containers, indicating the importance of risk assessment for the application of flexible plastic containers. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  6. Review: UK medicines likely to be affected by the proposed European Medicines Agency's guidelines on phthalates.

    Science.gov (United States)

    Jamieson, Lisa; McCully, William

    2015-06-13

    Phthalates are excipients in drug formulations. However, concerns have been raised about the effects of particular phthalates on reproduction and development. As a result the EMA has introduced guidelines for permitted daily exposure (PDE) limits for certain phthalates. Therefore, the objective of this study was to identify UK licensed medicines that contain the relevant phthalates and determine if they fall within the recommended PDE. The eMC was used to identify which UK licensed medicines contain the phthalates in question. Companies were then contacted for information on the phthalate levels in their products, which was compared with the PDE recommended by the EMA. The eMC search revealed that 54 medicines contained at least one of the phthalates in question. However, only six medicines, namely Asacol 800 mg MR (Warner Chilcott UK), Epilim 200 Gastro-resistant tablets (Sanofi), Prednisolone 2.5 mg and 5 mg Gastro-resistant tablets (Actavis UK), Vivotif (Crucell Italy S.r.l), and Zentiva 200 mg Gastro-resistant tablets (Winthrop Pharmaceuticals UK), were identified as containing levels that exceeded the recommended PDE. These findings indicate that very few UK licensed medicines will be affected by the proposed EMA guidelines. For those medicines identified as exceeding recommendations, these findings highlight the need to instigate a risk-benefit review.

  7. Parental Concern about Environmental Chemical Exposures and Children's Urinary Concentrations of Phthalates and Phenols.

    Science.gov (United States)

    Pell, Tripler; Eliot, Melissa; Chen, Aimin; Lanphear, Bruce P; Yolton, Kimberly; Sathyanarayana, Sheela; Braun, Joseph M

    2017-07-01

    To examine whether parents' concerns about environmental chemical exposures were associated with urinary phthalate and phenol concentrations in their school-age children. In a prospective cohort of 218 mother-child pairs from Cincinnati, Ohio (2010-2014), we measured 11 phthalate metabolites and 5 phenols in urine samples when children were age 8 years and used questionnaire data from caregivers. We estimated the covariate-adjusted percent difference in phthalates and phenols among children of parents who expressed concern about environmental chemical exposures compared with children whose parents did not. Concentrations of 4 phthalates, bisphenol S, and bisphenol A were lower among children whose parents expressed concern about environmental chemicals (n = 122) compared with those who did not (n = 96). Di-2-ethylhexyl phthalate metabolites, bisphenol S, and bisphenol A concentrations were 23% (95% CI -38, -5), 37% (95% CI -49, -21), and 13% (95% CI -26, 3) lower, respectively, among children whose parents expressed concern compared with those whose parents did not. Triclosan concentrations were 35% greater (95% CI -2, 87) among children whose parents expressed concern compared with children whose parents did not. Parental concern about environmental chemicals was associated with lower childhood urine concentrations of several phthalates and phenols; unexpectedly, parental concern was associated with greater triclosan concentrations. These results suggest that parental concern may be an important factor in mitigating children's phthalate and phenol exposures. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Dietary Phthalate Exposure in Pregnant Women and the Impact of Consumer Practices

    Science.gov (United States)

    Serrano, Samantha E.; Karr, Catherine J.; Seixas, Noah S.; Nguyen, Ruby H. N.; Barrett, Emily S.; Janssen, Sarah; Redmon, Bruce; Swan, Shanna H.; Sathyanarayana, Sheela

    2014-01-01

    Phthalates are ubiquitous endocrine-disrupting chemicals that are contaminants in food and contribute to significant dietary exposures. We examined associations between reported consumption of specific foods and beverages and first trimester urinary phthalate metabolite concentrations in 656 pregnant women within a multicenter cohort study, The Infant Development and Environment Study (TIDES), using multivariate regression analysis. We also examined whether reported use of ecofriendly and chemical-free products was associated with lower phthalate biomarker levels in comparison to not following such practices. Consumption of one additional serving of dairy per week was associated with decreases of 1% in the sum of di-2-ethylhexyl phthalate (DEHP) metabolite levels (95% CI: −2.0, −0.2). Further, participants who reported sometimes eating homegrown food had monoisobutyl phthalate (MiBP) levels that were 16.6% lower (95% CI: −29.5, −1.3) in comparison to participants in the rarely/never category. In contrast to rarely/never eating frozen fruits and vegetables, participants who reported sometimes following this practice had monobenzyl phthalate (MBzP) levels that were 21% higher (95% CI: 3.3, 41.7) than rarely/ever respondents. Future study on prenatal dietary phthalate exposure and the role of consumer product choices in reducing such exposure is needed. PMID:24927036

  9. Influence of phthalates on in vitro innate and adaptive immune responses.

    Directory of Open Access Journals (Sweden)

    Juliana Frohnert Hansen

    Full Text Available Phthalates are a group of endocrine disrupting chemicals, suspected to influence the immune system. The aim of this study was to investigate the influence of phthalates on cytokine secretion from human peripheral blood mononuclear cells. Escherichia coli lipopolysaccharide and phytohemagglutinin-P were used for stimulation of monocytes/macrophages and T cells, respectively. Cells were exposed for 20 to 22 hours to either di-ethyl, di-n-butyl or mono-n-butyl phthalate at two different concentrations. Both diesters were metabolised to their respective monoester and influenced cytokine secretion from both monocytes/macrophages and T cells in a similar pattern: the secretion of interleukin (IL-6, IL-10 and the chemokine CXCL8 by monocytes/macrophages was enhanced, while tumour necrosis factor (TNF-α secretion by monocytes/macrophages was impaired, as was the secretion of IL-2 and IL-4, TNF-α and interferon-γ by T cells. The investigated phthalate monoester also influenced cytokine secretion from monocytes/macrophages similar to that of the diesters. In T cells, however, the effect of the monoester was different compared to the diesters. The influence of the phthalates on the cytokine secretion did not seem to be a result of cell death. Thus, results indicate that both human innate and adaptive immunity is influenced in vitro by phthalates, and that phthalates therefore may affect cell differentiation and regenerative and inflammatory processes in vivo.

  10. Food safety involving ingestion of foods and beverages prepared with phthalate-plasticizer-containing clouding agents.

    Science.gov (United States)

    Yen, Tzung-Hai; Lin-Tan, Dan-Tzu; Lin, Ja-Liang

    2011-11-01

    In May 2011, the illegal use of the phthalate plasticizer di(2-ethylhexyl) phthalate in clouding agents for use in foods and beverages was reported in Taiwan. This food scandal has caused shock and panic among the majority of Taiwanese people and has attracted international attention. Phthalate exposure is assessed by ambient monitoring or human biomonitoring. Ambient monitoring relies on measuring chemicals in environmental media, foodstuff and consumer products. Human biomonitoring determines body burden by measuring the chemicals, their metabolites or specific reaction products in human specimens. In mammalian development, the fetus is set to develop into a female. Because the female phenotype is the default, impairment of testosterone production or action before the late phase may lead to feminizing characteristics. Phthalates disrupt the development of androgen-dependent structures by inhibiting fetal testicular testosterone biosynthesis. The spectrum of effects obtained following perinatal exposure of male rats to phthalates has remarkable similarities with the human testicular dysgenesis syndrome. Epidemiological studies have suggested associations between phthalate exposure and shorter gestational age, shorter anogenital distance, shorter penis, incomplete testicular descent, sex hormone alteration, precocious puberty, pubertal gynecomastia, premature thelarche, rhinitis, eczema, asthma, low birth weight, attention deficit hyperactivity disorder, low intelligence quotient, thyroid hormone alteration, and hypospadias in infants and children. Furthermore, many studies have suggested associations between phthalate exposure and increased sperm DNA damage, decreased proportion of sperm with normal morphology, decreased sperm concentration, decreased sperm morphology, sex hormone alteration, decreased pulmonary function, endometriosis, uterine leiomyomas, breast cancer, obesity, hyperprolactinemia, and thyroid hormone alteration in adults. Finally, the number of

  11. [Analysis of phthalates in plastic food-packaging bags by thin layer chromatography].

    Science.gov (United States)

    Chen, Hui; Wang, Yuan; Zhu, Ruohua

    2006-01-01

    The method for simultaneous determination of four phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) in plastic food-packaging bags by thin layer chromatography (TLC) was developed. The plastic food-packaging bags were extracted with ethanol by ultrasonication, then the mixture was filtrated through membrane (0.45 microm). The mixture of ethyl acetate-anhydrous ether-isooctane (1 : 4 : 15, v/v) was used as developing agent on the TLC silica gel plate for development. The filtered liquid was spotted on the TLC plate dealt by acetone, and detected with scanning wavelength of 275 nm and reference wavelength of 340 nm. The qualitative analysis of the phthalates was performed using the R(f) values of the chromatogram. The quantitative analysis was performed with external standard method. Good linearities were obtained for DMP, DEP, DBP and DEHP. The detection limits were 2.1 ng for DMP, 2.4 ng for DEP, 3.4 ng for DBP and 4.0 ng for DEHP. The relative standard deviations (RSDs) of the four phthalates were 2.8% - 3.5%. The recoveries of the four phthalate standards in real sample were 78.58% - 111.04%. The method presented has the advantages of high precision, high sensitivity, small sample size, and simple pretreatment . The method was used to detect the four phthalates in the food-packaging bags. The contents in real samples were close to the results by gas chromatography.

  12. Food safety involving ingestion of foods and beverages prepared with phthalate-plasticizer-containing clouding agents

    Directory of Open Access Journals (Sweden)

    Tzung-Hai Yen

    2011-11-01

    Full Text Available In May 2011, the illegal use of the phthalate plasticizer di(2-ethylhexyl phthalate in clouding agents for use in foods and beverages was reported in Taiwan. This food scandal has caused shock and panic among the majority of Taiwanese people and has attracted international attention. Phthalate exposure is assessed by ambient monitoring or human biomonitoring. Ambient monitoring relies on measuring chemicals in environmental media, foodstuff and consumer products. Human biomonitoring determines body burden by measuring the chemicals, their metabolites or specific reaction products in human specimens. In mammalian development, the fetus is set to develop into a female. Because the female phenotype is the default, impairment of testosterone production or action before the late phase may lead to feminizing characteristics. Phthalates disrupt the development of androgen-dependent structures by inhibiting fetal testicular testosterone biosynthesis. The spectrum of effects obtained following perinatal exposure of male rats to phthalates has remarkable similarities with the human testicular dysgenesis syndrome. Epidemiological studies have suggested associations between phthalate exposure and shorter gestational age, shorter anogenital distance, shorter penis, incomplete testicular descent, sex hormone alteration, precocious puberty, pubertal gynecomastia, premature thelarche, rhinitis, eczema, asthma, low birth weight, attention deficit hyperactivity disorder, low intelligence quotient, thyroid hormone alteration, and hypospadias in infants and children. Furthermore, many studies have suggested associations between phthalate exposure and increased sperm DNA damage, decreased proportion of sperm with normal morphology, decreased sperm concentration, decreased sperm morphology, sex hormone alteration, decreased pulmonary function, endometriosis, uterine leiomyomas, breast cancer, obesity, hyperprolactinemia, and thyroid hormone alteration in adults

  13. Urinary Phthalate Metabolites Are Associated with Body Mass Index and Waist Circumference in Chinese School Children

    Science.gov (United States)

    Wang, Hexing; Zhou, Ying; Tang, Chuanxi; He, Yanhong; Wu, Jingui; Chen, Yue; Jiang, Qingwu

    2013-01-01

    Background Lab studies have suggested that ubiquitous phthalate exposures are related to obesity, but relevant epidemiological studies are scarce, especially for children. Objective To investigate the association of phthalate exposures with body mass index (BMI) and waist circumference (WC) in Chinese school children. Methods A cross-sectional study was conducted in three primary and three middle schools randomly selected from Changning District of Shanghai City of China in 2011–2012. According to the physical examination data in October, 2011, 124 normal weight, 53 overweight, and 82 obese students 8–15 years of age were randomly chosen from these schools on the basis of BMI-based age- and sex-specific criterion. First morning urine was collected in January, 2012, and fourteen urine phthalate metabolites (free plus conjugated) were determined by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Multiple linear regression was used to explore the associations between naturally log-transformed urine phthalate metabolites and BMI or WC. Results The urine specific gravity-corrected concentrations of nine urine phthalate metabolites and five molar sums were positively associated with BMI or WC in Chinese school children after adjustment for age and sex. However, when other urine phthalate metabolites were included in the models together with age and sex as covariables, most of these significant associations disappeared except for mono (2-ethylhexyl) phthalate (MEHP) and monoethyl phthalate (MEP). Additionally, some associations showed sex- or age-specific differences. Conclusions Some phthalate exposures were associated with BMI or WC in Chinese school children. Given the cross-sectional nature of this study and lack of some important obesity-related covariables, further studies are needed to confirm the associations. PMID:23437242

  14. Reducing prenatal phthalate exposure through maternal dietary changes: results from a pilot study

    Science.gov (United States)

    Barrett, Emily S.; Velez, Marissa; Qiu, Xing; Chen, Shaw-Ree

    2016-01-01

    Objectives Diet is a major source of exposure to certain phthalates, a class of environmental chemicals associated with endocrine disruption in animal models and humans. Several studies have attempted to lower phthalate exposure through carefully designed dietary interventions, with inconsistent results. We conducted a dietary intervention pilot study with the objective to lower phthalate exposure in low-income pregnant women, a particularly vulnerable population. Methods Ten pregnant women consumed a provided diet consisting of mostly fresh, organic foods for three days. We collected urine samples before, during, and after the intervention and conducted semi-structured interviews to assess the feasibility and acceptability of the intervention. We used repeated measures ANOVA and paired t-tests to assess differences in urinary phthalate metabolite concentrations across the study, focusing on the metabolites of di-2-ethylhexyl phthalate (DEHP), a phthalate of particular interest, and their molar sum (∑DEHP). Results Phthalate metabolite concentrations did not change appreciably during the intervention period. We observed no significant difference in ∑DEHP metabolite concentrations across the three time periods (F=0.21; adjusted p-value=0.65), and no reduction during the intervention as compared to baseline (t=−1.07, adjusted p-value=0.51). Results of interviews indicated that participants were not motivated to make dietary changes to potentially reduce chemical exposures outside of the study. Conclusions Despite the small sample size, our results suggest that promoting dietary changes to lower phthalate exposure may not be an effective public health measure. Reducing the use of phthalates in food processing and packaging may be a better solution to lowering exposure on a population level. PMID:25652062

  15. Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro

    International Nuclear Information System (INIS)

    Gupta, Rupesh K.; Singh, Jeffery M.; Leslie, Tracie C.; Meachum, Sharon; Flaws, Jodi A.; Yao, Humphrey H-C

    2010-01-01

    Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 μg/ml) and MEHP (0.1-10 μg/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin-dependant-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators.

  16. Effects of phthalates on the human corneal endothelial cell line B4G12

    DEFF Research Database (Denmark)

    Krüger, Tanja; Cao, Yi; Kjærgaard, Søren K.

    2012-01-01

    Phthalates are industrial chemicals used in many cosmetics. We evaluated an in vitro model for eye irritancy testing using the human corneal endothelial cell line B4G12. Cell proliferation and toxicity were assessed after exposing to di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2...... toxicity was observed for DBP and BBP. Upon DBP exposure at nontoxic concentrations, a significant increased gene expression and cytokine cell secretion were observed for interleukin-1ß (IL-1ß) and IL-8, and also an increased IL-6 secretion was observed. In conclusion, the human corneal endothelial cell...

  17. Migration of Phthalates from Plastic Containers into Soft Drinks and Mineral Water

    Directory of Open Access Journals (Sweden)

    Jasna Bošnir

    2007-01-01

    Full Text Available The aim of this study was to determine the level of phthalate migration from plastic containers to soft drinks and mineral water and to identify a possible relationship between the amount and type of phthalate migration, type of preservative used, and the pH of the sample. The analysis included 45 samples of products packed in containers made from polyethylene terephthalate. The samples were divided into 5 groups: group 1 (N=9, soft drinks preserved with orthophosphoric acid; group 2 (N=14, soft drinks preserved with Na-benzoate; group 3 (N=5, soft drinks preserved with K-sorbate; group 4 (N=8, soft drinks preserved with a combination of Na-benzoate and K-sorbate; and group 5 (N=9, mineral water without preservatives. The samples were analyzed by the method of gas chromatography, with a detection limit of 0.005 μg/L. The mean pool phthalate level and mean pH value were 91.67 μg/L and 2.82±0.30 in group 1; 116.93 μg/L and 2.75±0.32 in group 2; 819.40 μg/L and 2.88±0.15 in group 3; 542.63 μg/L and 2.82±0.54 in group 4; and 20.22 μg/L and 5.82±1.26 in group 5, respectively. The highest rate of migration to soft drinks was recorded for dimethyl phthalate, ranging from 53.51 to 92.73 %, whereas dibutyl phthalate and diethylhexyl phthalate showed highest rate of migration to the mineral water (56.04 and 43.42 %, respectively. The highest level of phthalate migration from plastic containers to soft drinks was found in the products preserved with K-sorbate. The rate of phthalate migration appears to be influenced also by the drink pH, i.e. the lower the pH value, the greater the phthalate migration. Dimethyl phthalate showed highest migration to preserved drinks as an acidic medium, which might stimulate modification in the composition of plastic containers according to the type and composition of the product. Additional studies in a greater number of samples are needed. Although the phthalate levels measured in these samples pose no risk for

  18. Recycling of plastic waste: Presence of phthalates in plastics from households and industry

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

    2016-01-01

    Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large...... recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...

  19. Hydrogen detector

    International Nuclear Information System (INIS)

    Kumagaya, Hiromichi; Yoshida, Kazuo; Sanada, Kazuo; Chigira, Sadao.

    1994-01-01

    The present invention concerns a hydrogen detector for detecting water-sodium reaction. The hydrogen detector comprises a sensor portion having coiled optical fibers and detects hydrogen on the basis of the increase of light transmission loss upon hydrogen absorption. In the hydrogen detector, optical fibers are wound around and welded to the outer circumference of a quartz rod, as well as the thickness of the clad layer of the optical fiber is reduced by etching. With such procedures, size of the hydrogen detecting sensor portion can be decreased easily. Further, since it can be used at high temperature, diffusion rate is improved to shorten the detection time. (N.H.)

  20. Analysis and Assessment of Exposure to Selected Phthalates Found in Children’s Toys in Christchurch, New Zealand

    Directory of Open Access Journals (Sweden)

    Matthew James Ashworth

    2018-01-01

    Full Text Available Internationally several phthalates are subject to regulatory control regarding maximum allowable concentrations in children’s toys. Such regulation is not in place in New Zealand. Phthalates have been associated with developmental toxicity and endocrine disruption. We determined the concentration of seven phthalates in children’s toys purchased in Christchurch, New Zealand. These results provided data for an exposure assessment deriving Hazard Indices (HI for oral and dermal exposure routes in children, based on the concentration of mixtures of phthalates shown by the EU to produce either reproductive/developmental or hepatotoxic effects. Of the 49 toys analyzed, 65% contained at least one phthalate at a concentration of >0.1% by mass; and 35% contained multiple-phthalates at individual concentrations of >0.1%. A HI of 3.4 was derived for the combined exposures to the four phthalates associated with reproductive and developmental effects. A HI of 0.3 was derived for the group of phthalates associated with hepatotoxic effects. Five phthalates were detected at levels exceeding the EU regulatory limit of 0.1% by mass. Risk assessment calculations indicate that, using realistic exposure scenarios, the worst-case combined exposure to phthalates associated with developmental toxicity exceeded a HI of 1 so may cause adverse developmental effects.

  1. Children's Phthalate Intakes and Resultant Cumulative Exposures Estimated from Urine Compared with Estimates from Dust Ingestion, Inhalation and Dermal Absorption in Their Homes and Daycare Centers

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Weschler, Charles J; Langer, Sarka

    2013-01-01

    Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of a...... of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values.......Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age....... For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child's home and daycare center. Based on the urine samples, DEHP had the highest total daily intake...

  2. Phthalate esters in the environment: A critical review of their occurrence, biodegradation, and removal during wastewater treatment processes.

    Science.gov (United States)

    Gao, Da-Wen; Wen, Zhi-Dan

    2016-01-15

    Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.-10.4 ng/m(3), N.D.-31.7 μg/L, N.D.-316 μg/kg dry weight, and N.D.-200 μg/kg dry weight, N.D.-43.27 μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%-71% to 95%-97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Hydrogen - From hydrogen to energy production

    International Nuclear Information System (INIS)

    Klotz, Gregory

    2005-01-01

    More than a century ago, Jules Verne wrote in 'The Mysterious Island' that water would one day be employed as fuel: 'Hydrogen and oxygen, which constitute it, used singly or together, will furnish an inexhaustible source of heat and light'. Today, the 'water motor' is not entirely the dream of a writer. Fiction is about to become fact thanks to hydrogen, which can be produced from water and when burned in air itself produces water. Hydrogen is now at the heart of international research. So why do we have such great expectations of hydrogen? 'Hydrogen as an energy system is now a major challenge, both scientifically and from an environmental and economic point of view'. Dominated as it is by fossil fuels (oil, gas and coal), our current energy system has left a dual threat hovering over our environment, exposing the planet to the exhaustion of its natural reserves and contributing to the greenhouse effect. If we want sustainable development for future generations, it is becoming necessary to diversify our methods of producing energy. Hydrogen is not, of course, a source of energy, because first it has to be produced. But it has the twofold advantage of being both inexhaustible and non-polluting. So in the future, it should have a very important role to play. (author)

  4. Hydrogen highway

    International Nuclear Information System (INIS)

    Anon

    2008-01-01

    The USA Administration would like to consider the US power generating industry as a basis ensuring both the full-scale production of hydrogen and the widespread use of the hydrogen related technological processes into the economy [ru

  5. Urinary Phthalate Metabolite Concentrations and Reproductive Outcomes among Women Undergoing in Vitro Fertilization: Results from the EARTH Study.

    Science.gov (United States)

    Hauser, Russ; Gaskins, Audrey J; Souter, Irene; Smith, Kristen W; Dodge, Laura E; Ehrlich, Shelley; Meeker, John D; Calafat, Antonia M; Williams, Paige L

    2016-06-01

    Evidence from both animal and human studies suggests that exposure to phthalates may be associated with adverse female reproductive outcomes. We evaluated the associations between urinary concentrations of phthalate metabolites and outcomes of assisted reproductive technologies (ART). This analysis included 256 women enrolled in the Environment and Reproductive Health (EARTH) prospective cohort study (2004-2012) who provided one to two urine samples per cycle before oocyte retrieval. We measured 11 urinary phthalate metabolites [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), monoethyl phthalate (MEP), monocarboxyisooctyl phthalate (MCOP), monocarboxyisononyl phthalate (MCNP), and mono(3-carboxypropyl) phthalate (MCPP)]. We used generalized linear mixed models to evaluate the association of urinary phthalate metabolites with in vitro fertilization (IVF) outcomes, accounting for multiple IVF cycles per woman. In multivariate models, women in the highest as compared with lowest quartile of MEHP, MEHHP, MEOHP, MECPP, ΣDEHP (MEHP + MEHHP + MEOHP + MECPP), and MCNP had lower oocyte yield. Similarly, the number of mature (MII) oocytes retrieved was lower in the highest versus lowest quartile for these same phthalate metabolites. The adjusted differences (95% CI) in proportion of cycles resulting in clinical pregnancy and live birth between women in the fourth versus first quartile of ΣDEHP were -0.19 (-0.29, -0.08) and -0.19 (-0.28, -0.08), respectively, and there was also a lower proportion of cycles resulting in clinical pregnancy and live birth for individual DEHP metabolites. Urinary concentrations of DEHP metabolites were inversely associated with oocyte yield, clinical pregnancy, and live birth following ART. Hauser R, Gaskins AJ, Souter I, Smith

  6. Rapid and molecular selective electrochemical sensing of phthalates in aqueous solution

    KAUST Repository

    Zia, Asif I.; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Al-Bahadly, Ibrahim H.; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2015-01-01

    molecular imprinted polymer (MIP) to introduce selectivity for the di(2-ethylhexyl) phthalate (DEHP) molecule. Various concentrations (1-100. ppm) of DEHP in deionized MilliQ water were tested using the functionalized sensing surface to capture the analyte

  7. Improved detection limits for phthalates by selective solid-phase micro-extraction

    KAUST Repository

    Zia, Asif I.; Afsarimanesh, Nasrin; Xie, Li; Nag, Anindya; Al-Bahadly, I. H.; Yu, P. L.; Kosel, Jü rgen

    2016-01-01

    Presented research reports on an improved method and enhanced limits of detection for phthalates; a hazardous additive used in the production of plastics by solid-phase micro-extraction (SPME) polymer in comparison to molecularly imprinted solid

  8. Serum Phthalate and Triclosan Levels Have Opposing Associations With Risk Factors for Gestational Diabetes Mellitus

    DEFF Research Database (Denmark)

    Fisher, Benjamin G; Frederiksen, Hanne; Andersson, Anna-Maria

    2018-01-01

    Certain phthalates and bisphenol A (BPA) have been associated with insulin resistance and type 2 diabetes in non-pregnant adults, but studies of gestational diabetes mellitus (GDM) have reported conflicting results for phthalates and no associations with BPA. Our aim was to investigate...... levels were positively associated with 120-min plasma glucose (adjusted β 0.268 and 0.183, p = 0.0002 and 0.010, respectively) in mid-pregnancy. No other monotonic associations were detected between phthalate or phenol levels and fasting or stimulated plasma glucose, β-cell function, insulin resistance......, or 60-min disposition index. Our results support a glycaemia-raising effect of phthalates during pregnancy, consistent with findings in non-pregnant populations and suggest a possible protective effect of exposure to TCS against GDM....

  9. Phthalates in surface water - a method for routine trace level analysis

    International Nuclear Information System (INIS)

    Furtmann, K.

    1994-01-01

    A routine method for the determination of phthalates in water is presented. It is suitable for all kinds of water like surface water, waste water, landfill leachate, rain water and ground water. Unfiltered water samples including all suspended particulate matter are extracted by solid-phase extraction in an all-glass apparatus using RPC-18. The extracts are measured by GC/MSD in the SIM mode. Due to an easy but efficient decontamination technique, method blanks could be decreased below 0.02 μg/l for all phthalates. The detection limits are 0.01 to 0.02 μg/l, the determination limits are 0.02 to 0.05 μg/l. Recovery for all phthalates is about 98% (± 5%). Phthalates were measured in about 400 samples of water of the river Rhine and its main affluents in Northrhine-Westfalia. (orig.)

  10. Electrochemical impedance spectroscopy based MEMS sensors for phthalates detection in water and juices

    KAUST Repository

    Zia, Asif I; Syaifudin, A R Mohd; Mukhopadhyay, S C; Yu, P L; Al-Bahadly, I H; Gooneratne, Chinthaka P; Kosel, Jü rgen; Liao, Tai-Shan

    2013-01-01

    Phthalate esters are ubiquitous environmental and food pollutants well known as endocrine disrupting compounds (EDCs). These developmental and reproductive toxicants pose a grave risk to the human health due to their unlimited use in consumer

  11. Phthalates production from Curvularia senegalensis (Speg.) Subram, a fungal species associated to crops of commercial value.

    Science.gov (United States)

    Lucas, Esther M F; Abreu, Lucas M; Marriel, Ivanildo E; Pfenning, Ludwig H; Takahashi, Jacqueline A

    2008-01-01

    The fungal species Curvularia senegalensis was isolated from a soil sample collected at a Brazilian region of cerrado transition. This microorganism was grown in vitro and the extract of the culture medium was fractionated by chromatographic methods yielding an oil rich in phthalates, from which seven derivatives were identified by infrared, 1H and 13C NMR and mass spectrometry as 1-hexyl-2-propylphthalate, 1-ethyl-2-heptylphthalate, 1-hexyl-2-butylphthalate, 1-heptyl-2-proylphthalate, 1-propyl-2-nonylphthalate and two positional isomers of 1-decyl-2-butane phthalate. This is the first report on the phthalates production by Curvularia senegalensis revealing a scientific basis for the use of this species on biodegradation experiments. Since C. senegalensis is a very common pathogen in some commercial crops, presence of highly toxic phthalates on the final feed products should be investigated.

  12. Analysis of Phthalate Ester Content in PVC Plastics by means of FT-Raman Spectroscopy

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Polyvinyl chloride, PVC or [CH2-CHCl]n , is a common polymer used extensively for a wide range of industrial and household products. To achieve the proper material characteristics (e.g. softness, ductility), plasticizers such as phthalates are usually added to the otherwise hard and brittle PVC......, medical devices and toys may harm the e.g. reproductive organs of exposed infants. PVC is readily distinguished from other common polymers (e.g. polyethylene, polypropylene, polystyrene) by the use of Raman spectroscopy. By far the most commonly used phthalate plasticizer in PVC is di(2-ethylhexyl......-phenyl group, and as the relative intensities of the six bands vary only slightly from one phthalate ester to the next one we have obtained an identifiable, characteristic fingerprint of the phthalate ester group as a whole. By use of the set of six bands, which are common to all the measured Raman spectra, we...

  13. Thermal and enzymatic pretreatment of sludge containing phthalate esters prior to mesophilic anaerobic digestion

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Yenal, U.; Ahring, Birgitte Kiær

    2004-01-01

    The present study aimed at investigating the effect of thermal pretreatment of sludge at 70degreesC on the anaerobic degradation of three commonly found phthalic acid esters (PAE): di-ethyl phthalate (DEP), di-butyl phthalate (DBP), and di-ethylhexyl phthalate (DEHP). Also, the enzymatic treatment...... at 28degreesC with a commercial lipase was studied as a way to enhance PAE removal. Pretreatment at 70degreesC of the sludge containing PAE negatively influenced the anaerobic biodegradability of phthalate esters at 37degreesC. The observed reduction of PAE biodegradation rates after the thermal...... pretreatment was found to be proportional to the PAE solubility in water: the higher the solubility, the higher the percentage of the reduction (DEP > DBP > DEHP). PAE were slowly degraded during the pretreatment at 70degreesC, yet this was probably due to physicochemical reactions than to microbial...

  14. Phthalate-Induced Pathology in the Foetal Testis Involves More Than Decreased Testosterone Production

    Science.gov (United States)

    Foetal exposure to phthalates is known to adversely impact male reproductive development and function. Developmental anomalies of reproductive tract have been attributed to impaired testosterone synthesis. However, species differences in the ability to produce testosterone have...

  15. In vitro assessment of phthalate acid esters-trypsin complex formation.

    Science.gov (United States)

    Chi, Zhenxing; Zhao, Jing; Li, Weiguo; Araghi, Arash; Tan, Songwen

    2017-10-01

    In this work, interactions of three phthalate acid esters (PAEs), including dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP), with trypsin have been studied in vitro, under simulated physiological conditions using multi-spectroscopic techniques and molecular modeling. The results show that these PAEs can bind to the trypsin, forming trypsin-PAEs complexes, mainly via hydrophobic interactions, with the affinity order of DMP > DEP > DBP. Binding to the PAEs is found to result in molecular deformation of trypsin. The modeling results suggest that only DBP can bind with the amino acid residues of the catalytic triad and S1 binding pocket of trypsin, leading to potential competitive enzyme inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Study of the repartition of phthalate esters during distillation of wine for spirit production.

    Science.gov (United States)

    Montevecchi, Giuseppe; Masino, Francesca; Di Pascale, Nicolas; Vasile Simone, Giuseppe; Antonelli, Andrea

    2017-12-15

    Due to health concerns and legal matters, an investigation to limit phthalates esters (PEAs) in spirits is necessary. A lab still was used to perform pilot distillations according to the official method for brandy production in order to explore the repartition into the distilled fractions of each PAE. The process was divided in two steps: a première chauffe and a bonne chauffe. The former step included the cut into heads, heart and tails, while the latter into heads, brandy, secondes, and tails. The behaviour of each PAE during distillation was affected by its own chemical nature. Dibutyl phthalate (DBP) was entirely carried over into the distillate, while bis(2-ethylhexyl) phthalate (DEHP) only partially, and diisononyl phthalate (DINP) accumulated in the stillage. During the bonne chauffe, DBP and DEHP accumulated in the secondes more than in the brandy. A rectification step of the secondes was demonstrated to considerably reduce PAEs concentration. Copyright © 2017. Published by Elsevier Ltd.

  17. Dipentyl Phthalate F1 Male rat necropsy data, requested by a ...

    Science.gov (United States)

    This is a dataset, and it has no abstract. See the manuscript for additional information. Gray LE Jr, Furr J, Tatum-Gibbs KR, Lambright C, Sampson H, Hannas BR, Wilson VS, Hotchkiss A, Foster PM. Establishing the "Biological Relevance" of DipentylPhthalate Reductions in Fetal Rat Testosterone Production and Plasma and Testis Testosterone Levels. Toxicol Sci. 2016 Jan;149(1):178-91. doi: 10.1093/toxsci/kfv224. Epub 2015 Oct 9. PubMed PMID: 26454885; PubMed CentralPMCID: PMC4715258. Dipentyl Phthalate F1 Male rat necropsy data from our 2016 publication. These data were requested by a mathematical statistician in NCEA that is using the data for nested BMD calculations for their ongoing assessment of this phthalate. We continue to provide NCEA and other regulatory groups data on the phthalates for their assessments.

  18. Exposure to bisphenol A, but not phthalates, increases spontaneous diabetes type 1 development in NOD mice.

    Science.gov (United States)

    Bodin, Johanna; Kocbach Bølling, Anette; Wendt, Anna; Eliasson, Lena; Becher, Rune; Kuper, Frieke; Løvik, Martinus; Nygaard, Unni Cecilie

    2015-01-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune destruction of insulin producing pancreatic beta-cells due to a genetic predisposition and can be triggered by environmental factors. We have previously shown that bisphenol A (BPA) accelerates the spontaneous development of diabetes in non-obese diabetic (NOD) mice. Here, we hypothesized that oral exposure to a mixture of the endocrine disruptors BPA and phthalates, relevant for human exposure, would accelerate diabetes development compared to BPA alone. NOD mice were exposed to BPA (1 mg/l), a mixture of phthalates (DEHP 1 mg/l, DBP 0.2 mg/l, BBP 10 mg/l and DiBP 20 mg/l) or a combination of BPA and the phthalate mixture through drinking water from conception and throughout life. Previous observations that BPA exposure increased the prevalence of diabetes and insulitis and decreased the number of tissue resident macrophages in pancreas were confirmed, and extended by demonstrating that BPA exposure also impaired the phagocytic activity of peritoneal macrophages. None of these effects were observed after phthalate exposure alone. The phthalate exposure in combination with BPA seemed to dampen the BPA effects on macrophage number and function as well as diabetes development, but not insulitis development. Exposure to BPA alone or in combination with phthalates decreased cytokine release (TNFα, IL-6, IL-10, IFNγ, IL-4) from in vitro stimulated splenocytes and lymph node cells, indicating systemic changes in immune function. In conclusion, exposure to BPA, but not to phthalates or mixed exposure to BPA and phthalates, accelerated diabetes development in NOD mice, apparently in part via systemic immune alterations including decreased macrophage function.

  19. Exposure to bisphenol A, but not phthalates, increases spontaneous diabetes type 1 development in NOD mice

    Directory of Open Access Journals (Sweden)

    Johanna Bodin

    2015-01-01

    Full Text Available Type 1 diabetes mellitus (T1DM is an autoimmune destruction of insulin producing pancreatic beta-cells due to a genetic predisposition and can be triggered by environmental factors. We have previously shown that bisphenol A (BPA accelerates the spontaneous development of diabetes in non-obese diabetic (NOD mice. Here, we hypothesized that oral exposure to a mixture of the endocrine disruptors BPA and phthalates, relevant for human exposure, would accelerate diabetes development compared to BPA alone. NOD mice were exposed to BPA (1 mg/l, a mixture of phthalates (DEHP 1 mg/l, DBP 0.2 mg/l, BBP 10 mg/l and DiBP 20 mg/l or a combination of BPA and the phthalate mixture through drinking water from conception and throughout life. Previous observations that BPA exposure increased the prevalence of diabetes and insulitis and decreased the number of tissue resident macrophages in pancreas were confirmed, and extended by demonstrating that BPA exposure also impaired the phagocytic activity of peritoneal macrophages. None of these effects were observed after phthalate exposure alone. The phthalate exposure in combination with BPA seemed to dampen the BPA effects on macrophage number and function as well as diabetes development, but not insulitis development. Exposure to BPA alone or in combination with phthalates decreased cytokine release (TNFα, IL-6, IL-10, IFNγ, IL-4 from in vitro stimulated splenocytes and lymph node cells, indicating systemic changes in immune function. In conclusion, exposure to BPA, but not to phthalates or mixed exposure to BPA and phthalates, accelerated diabetes development in NOD mice, apparently in part via systemic immune alterations including decreased macrophage function.

  20. Prenatal phthalate exposure and language development in toddlers from the Odense Child Cohort.

    Science.gov (United States)

    Olesen, Trine Staak; Bleses, Dorthe; Andersen, Helle Raun; Grandjean, Philippe; Frederiksen, Hanne; Trecca, Fabio; Bilenberg, Niels; Kyhl, Henriette Boye; Dalsager, Louise; Jensen, Inge Kjær; Andersson, Anna-Maria; Jensen, Tina Kold

    Phthalates are a group of chemicals found in a variety of consumer products. They have anti-androgenic properties and human studies have reported associations between prenatal phthalate exposure and neuropsychological development in the offspring despite different cognitive tests, different ages and varying timing of exposure. To investigate the association between prenatal phthalate exposure and language development in children aged 20-36months. In the Odense Child Cohort, we analyzed 3rd trimester urine samples of 518 pregnant women for content of metabolites of diethyl, di-n-butyl, diisobutyl, butylbenzyl, di(2-ethylhexyl), and diisononyl phthalate, adjusted for osmolality. Language development was addressed using the Danish version of the MacArthur-Bates Communicative Development Inventories "Words and Sentences". Associations were assessed using logistic regression models comparing children below and above the 15th percentile while stratifying by sex and adjusting for maternal age and educational level. Phthalate metabolites were detectable in all samples although in lower levels than previous studies. Among boys, increased prenatal phthalate exposure was associated with lower scores in language development; odds ratios for vocabulary score below the 15th percentile with doubling in monoethyl phthalate, and summed di-(2-ethylhexyl) phthalate metabolites were respectively 1.24 (95% confidence interval: 1.05,1.46), and 1.33 (1.01,1.75). Similar associations were found for language complexity. No associations were found for girls. Our findings are notable, as adverse associations were suggested even in this low-level exposed population, with only one spot urine sample for exposure assessment and control for confounders. Lower scores in early language development are of relevance to health as this test predicts later educational success. Copyright © 2017. Published by Elsevier Inc.

  1. Prenatal phthalate exposure and altered patterns of DNA methylation in cord blood.

    Science.gov (United States)

    Solomon, Olivia; Yousefi, Paul; Huen, Karen; Gunier, Robert B; Escudero-Fung, Maria; Barcellos, Lisa F; Eskenazi, Brenda; Holland, Nina

    2017-07-01

    Epigenetic changes such as DNA methylation may be a molecular mechanism through which environmental exposures affect health. Phthalates are known endocrine disruptors with ubiquitous exposures in the general population including pregnant women, and they have been linked with a number of adverse health outcomes. We examined the association between in utero phthalate exposure and altered patterns of cord blood DNA methylation in 336 Mexican-American newborns. Concentrations of 11 phthalate metabolites were analyzed in maternal urine samples collected at 13 and 26 weeks gestation as a measure of fetal exposure. DNA methylation was assessed using the Infinium HumanMethylation 450K BeadChip adjusting for cord blood cell composition. To identify differentially methylated regions (DMRs) that may be more informative than individual CpG sites, we used two different approaches, DMRcate and comb-p. Regional assessment by both methods identified 27 distinct DMRs, the majority of which were in relation to multiple phthalate metabolites. Most of the significant DMRs (67%) were observed for later pregnancy (26 weeks gestation). Further, 51% of the significant DMRs were associated with the di-(2-ethylhexyl) phthalate metabolites. Five individual CpG sites were associated with phthalate metabolite concentrations after multiple comparisons adjustment (FDR), all showing hypermethylation. Genes with DMRs were involved in inflammatory response (IRAK4 and ESM1), cancer (BRCA1 and LASP1), endocrine function (CNPY1), and male fertility (IFT140, TESC, and PRDM8). These results on differential DNA methylation in newborns with prenatal phthalate exposure provide new insights and targets to explore mechanism of adverse effects of phthalates on human health. Environ. Mol. Mutagen. 58:398-410, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention

    OpenAIRE

    Rudel, Ruthann A.; Gray, Janet M.; Engel, Connie L.; Rawsthorne, Teresa W.; Dodson, Robin E.; Ackerman, Janet M.; Rizzo, Jeanne; Nudelman, Janet L.; Brody, Julia Green

    2011-01-01

    Background: Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) are high-production-volume chemicals used in plastics and resins for food packaging. They have been associated with endocrine disruption in animals and in some human studies. Human exposure sources have been estimated, but the relative contribution of dietary exposure to total intake has not been studied empirically. Objectives: To evaluate the contribution of food packaging to exposure, we measured urinary BPA and phthalate...

  3. Photocatalytic degradation of diethyl phthalate using TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Pooja, E-mail: pooja.singla@thapar.edu; Pandey, O. P., E-mail: pooja.singla@thapar.edu; Singh, K., E-mail: pooja.singla@thapar.edu [School of Physics and Materials Science, Thapar University, Patiala-147004 (India)

    2014-04-24

    TiO{sub 2} nanoparticles predominantly in rutile phase are synthesized by ultrasonication assisted sol-gel method. TiO{sub 2} powder is characterized using X-ray powder diffraction and UV-vis diffuse reflectance. TiO{sub 2} is used as catalyst in photocatalytic degradation of Diethyl Phthalate. TiO{sub 2} exhibits good photocatalytic activity for the degradation of diethyl phthalate.

  4. Di-(2-Ethylhexyl Phthalate and Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Chiara Testa

    2012-04-01

    Full Text Available ASDs (autism spectrum disorders are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11 ± 5 years and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12 ± 5 years were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS, was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98% taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18 and 5-oxo-MEHP (46.0%, median 0.096 urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (r s=0.668, P<0.0001. The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for

  5. Hydrogen economy

    Energy Technology Data Exchange (ETDEWEB)

    Pahwa, P.K.; Pahwa, Gulshan Kumar

    2013-10-01

    In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Hydrogen has been proposed as the perfect fuel for this future energy system. The availability of a reliable and cost-effective supply, safe and efficient storage, and convenient end use of hydrogen will be essential for a transition to a hydrogen economy. Research is being conducted throughout the world for the development of safe, cost-effective hydrogen production, storage, and end-use technologies that support and foster this transition. This book discusses hydrogen economy vis-a-vis sustainable development. It examines the link between development and energy, prospects of sustainable development, significance of hydrogen energy economy, and provides an authoritative and up-to-date scientific account of hydrogen generation, storage, transportation, and safety.

  6. Multi objective optimization of performance parameters of a single cylinder diesel engine running with hydrogen using a Taguchi-fuzzy based approach

    International Nuclear Information System (INIS)

    Bose, Probir Kumar; Deb, Madhujit; Banerjee, Rahul; Majumder, Arindam

    2013-01-01

    Environmental issues and rapid exhaustion of fossil fuels are the major concerns over the past two decades to search for alternative fuels. Among various alternatives hydrogen is a long-term renewable and least polluting fuel. Its clean burning capability helps to meet the stern emission norms. Full substitution of diesel with hydrogen may not be convenient for the time being but employing of hydrogen in a diesel engine in dual fuel mode is possible. In this experimental investigation a TMI (timed manifold injection) system has been developed using ECU (electronic control unit) with varying injection strategy to deliver hydrogen on to the intake manifold. Through adopting this technique in the existing diesel engine a momentous improvement in performance and combustion parameters has been observed. The study also attempts to explain the application of the fuzzy logic based Taguchi analysis to optimize the performance parameters i.e. BSEC (Brake specific energy consumption), Vol. Eff. (Volumetric efficiency) and BTHE (brake thermal efficiency) for the different hydrogen injection strategies. - Highlights: • A timed manifold injection system has been developed which enhances the BTHE by 31.74% at full load conditions. • Use of hydrogen-diesel dual fuel of BSEC was reduced by a maximum of 68.98% at full load condition compared to diesel. • Τhe Vol. Eff. reduced by 73.14% in dual fuel mode as compared to 77.23% at full load condition with base diesel. • A fuzzy based Taguchi's parameter design technique has been involved in multi objective optimization for prediction. • Predicted optimum combination improved BTHE and Vol. Eff. by 24.04% and 72.87% respectively and reduced BSEC by 59.03%

  7. Concentrations of phthalates and DINCH metabolites in pooled urine from Queensland, Australia.

    Science.gov (United States)

    Gomez Ramos, M J; Heffernan, A L; Toms, L M L; Calafat, A M; Ye, X; Hobson, P; Broomhall, S; Mueller, J F

    2016-03-01

    Dialkyl phthalate esters (phthalates) are ubiquitous chemicals used extensively as plasticizers, solvents and adhesives in a range of industrial and consumer products. 1,2-Cyclohexane dicarboxylic acid, diisononyl ester (DINCH) is a phthalate alternative introduced due to a more favourable toxicological profile, but exposure is largely uncharacterised. The aim of this study was to provide the first assessment of exposure to phthalates and DINCH in the general Australian population. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100). Concentrations of free and total species were measured using online solid phase extraction isotope dilution high performance liquid chromatography tandem mass spectrometry. Concentrations ranged from 2.4 to 71.9ng/mL for metabolites of di(2-ethylhexyl)phthalate, and from <0.5 to 775ng/mL for all other metabolites. Our data suggest that phthalate metabolites concentrations in Australia were at least two times higher than in the United States and Germany; and may be related to legislative differences among countries. DINCH metabolite concentrations were comparatively low and consistent with the limited data available. Ongoing biomonitoring among the general Australian population may help assess temporal trends in exposure and assess the effectiveness of actions aimed at reducing exposures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Phthalate exposure, flavonoid consumption and breast cancer risk among Mexican women.

    Science.gov (United States)

    Mérida-Ortega, Ángel; Hernández-Alcaraz, César; Hernández-Ramírez, Raúl U; García-Martínez, Angélica; Trejo-Valdivia, Belem; Salinas-Rodríguez, Aarón; Svensson, Katherine; Cebrián, Mariano E; Franco-Marina, Francisco; López-Carrillo, Lizbeth

    2016-11-01

    To evaluate if selected phthalate exposure and flavonoid intake interact on breast cancer (BC) risk. Interviews and urine samples were obtained from 233 women with histologically confirmed BC and 221 healthy controls matched by age and place of residence, from various states of northern Mexico. Urinary metabolites concentrations of diethyl phthalate (DEP), butyl benzyl phthalate (BBzP) and dioctyl phthalate (DOP) were determined by solid-phase extraction coupled with high-performance liquid chromatography/isotope dilution/tandem mass spectrometry. Using a semiquantitative food frequency questionnaire, consumption of five types of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones and flavonols) was estimated according to three food groups: vegetables, fruits and legumes-oil seeds. A higher intake of anthocyanidins and flavan-3-ols (from vegetables), synergistically increased the negative association between BBzP and BC. No other significant flavonoid-phthalate multiplicative interactions on the risk for BC were found. The consumption of some flavonoids may interact with exposure to phthalates on the risk of BC. Epidemiological and underlying mechanisms information is still insufficient and requires further investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Phthalate exposure and reproductive parameters in young men from the general Swedish population.

    Science.gov (United States)

    Axelsson, Jonatan; Rylander, Lars; Rignell-Hydbom, Anna; Jönsson, Bo A G; Lindh, Christian H; Giwercman, Aleksander

    2015-12-01

    In animals, exposure to certain phthalates negatively affects the male reproductive function. Human results are conflicting and mostly based on subfertile males, in whom the association between exposure and reproductive function may differ from the general population. To study if levels of phthalate metabolites were associated with semen quality and reproductive hormones in general Swedish men. We recruited 314 young men delivering semen, urine and blood samples at the same visit. We analyzed reproductive hormones and several semen parameters including progressive motility and high DNA stainability (HDS)-a marker for sperm immaturity. In urine, we analyzed metabolites of phthalates, including diethylhexyl phthalate (DEHP). We studied associations between urinary levels of the metabolites and seminal as well as serum reproductive parameters, accounting for potential confounders. DEHP metabolite levels, particularly urinary mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), were negatively associated with progressive sperm motility, which was 11 (95% CI: 5.0-17) percentage points lower in the highest quartile of MECPP than in the lowest. Further, men in the highest quartile of the DEHP metabolite monoethylhexyl phthalate had 27% (95% CI: 5.5%-53%) higher HDS than men in the lowest quartile. DEHP metabolite levels seemed negatively associated with sperm motility and maturation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Predicted risk of childhood allergy, asthma, and reported symptoms using measured phthalate exposure in dust and urine

    DEFF Research Database (Denmark)

    Hsu, N.-Y.; Lee, C.-C.; Wang, J.-Y.

    2012-01-01

    The associated risk of phthalate exposure, both parent compounds in the home and their metabolites in urine, to childhood allergic and respiratory morbidity, after adjusting for exposures of indoor pollutants, especially bioaerosols, was comprehensively assessed. Levels of five phthalates...... symptoms. The relative contribution from exposure to phthalates and indoor biocontaminants in childhood allergic and respiratory morbidity is, for the first time, quantitatively assessed and characterized....

  11. The effects of phthalate and nonylphenol exposure on body size and secondary sexual characteristics during puberty.

    Science.gov (United States)

    Hou, Jia-Woei; Lin, Ching-Ling; Tsai, Yen-An; Chang, Chia-Huang; Liao, Kai-Wei; Yu, Ching-Jung; Yang, Winnie; Lee, Ming-Jun; Huang, Po-Chin; Sun, Chien-Wen; Wang, Yin-Han; Lin, Fang-Ru; Wu, Wen-Chiu; Lee, Meng-Chih; Pan, Wen-Harn; Chen, Bai-Hsiun; Wu, Ming-Tsang; Chen, Chu-Chih; Wang, Shu-Li; Lee, Ching-Chang; Hsiung, Chao Agnes; Chen, Mei-Lien

    2015-10-01

    Some phthalic acid esters (PAEs) and nonylphenol (NP) are endocrine-disrupting chemicals (EDCs) that are widely used in consumer products. Consequently, the general population is exposed simultaneously to both groups of chemicals. To investigate the single- and co-exposure effects of PAEs (DMP, DEP, DnBP, DiBP, BBzP, and DEHP) and NP on obesity and pubertal maturity to compare the body sizes of general adolescents with the complainants of the phthalate-tainted foods scandal that occurred in Taiwan. This study included 270 general adolescents aged 6.5-15.0 years and 38 complainants aged 6.5-8.5 years. Nine metabolites of the five PAEs and of NP were measured in urine. We used a questionnaire to evaluate pubertal maturity, measured anthropometric indices (APs) to assess body size, and collected urine samples to measure the two groups of chemicals. We found that urinary PAE metabolite concentrations (specifically, metabolites of DEP, DnBP, DiBP, and DEHP) were positively associated with the APs for abdominal obesity (including skinfold thickness, waist circumference, waist-to-height ratio, and waist-to-hip) and indicated a dose-response relationship. Mono-methyl phthalate (MMP) exposure was inversely associated with pubarche among boys. The daily intake of DEHP in general adolescents exceeded the reference doses (RfD-20 μg/kgbw/day) and tolerable daily intake (TDI-50 μg/kgbw/day) by 3.4% and 0.4%, respectively. No associations were observed between NP exposure or co-exposure and the APs or pubertal maturity. No significant differences were observed between general adolescents and the complainants with regard to weight, height, or BMI. The study suggests that PAE (specifically, DEP, DnBP, DiBP, and DEHP) exposure is associated with abdominal obesity in adolescents and that the APs for abdominal obesity are more sensitive than BMI for measuring obesity among adolescents. We suggest that the RfD and TDI for PAEs should be revised to provide sufficient protection

  12. Anaerobic degradation of phthalates in unsorted household wastes; Anaerob nedbrytning av ftalater med ymp fraan anaerobt behandlat hushaallsavfall

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, H.

    1993-10-01

    Phthalic acid and diethyl phthalate were tested for their biodegradability in anaerobic, unsorted household wastes. The compounds were analyzed by measuring absorbance after centrifugation of a water suspension. This cheap and rapid method was proven to be applicable. Both phthalic acid and diethyl phthalate disappeared almost completely in 1-3 months, using initial concentrations from 50 to 250 mg/l. The same methodology was used for diethylhexyl phthalate, but did not work. The stoichiometrically expected amounts of methane were not found for any of the compounds, and in case of diethyl phthalate an inhibition of the methane production was observed. (36 refs., 17 figs.)

  13. Comparative assessment of phthalate removal and risk in biological wastewater treatment systems of developing countries and small communities

    Energy Technology Data Exchange (ETDEWEB)

    Gani, Khalid Muzamil, E-mail: khalidmzml@gmail.com; Kazmi, Absar Ahmad, E-mail: absarakazmi@yahoo.com

    2016-11-01

    Phthalates are widely used in plastic and personnel care products. Being non-steroid endocrine disrupting compounds, their exposure have toxic effects on aquatic life and human health. The aim of this study was a comparative assessment of their fate and risk in full scale wastewater treatment along with influence of seasonal variations. Four priority phthalates, Diethylphthalate (DEP), Dibutylphthalate (DBP), Benzylbutyl phthalate (BBP) and Diethylhexyl phthalate (DEHP) were chosen for this study and wastewater treatment plants investigated were designed as nutrient removal based sequencing batch reactor (SBR), conventional activated sludge process (ASP) and up flow anaerobic sludge blanket (UASB) with polishing pond. Results showed that the main removal mechanism of phthalates was biotransformation with removal contribution of 74% in SBR, 65% in conventional ASP and 37% in UASB. Overall removal of phthalates was maximum in the treatment combination of UASB and pond (83%) followed by SBR (80%) and conventional ASP (74%). Seasonal influences on occurrence, removal and risk of these phthalates were also studied. The concentration of DEP, DBP and DEHP in untreated wastewater increased by 2, 7 and 2 μg/L, respectively in summer. However in sludge, only large molecular weight phthalates BBP and DEHP increased in winter by 3 mg/kg and 12 mg/kg, respectively. Seasonal variations in removal of phthalates were discrepant in each process with better removal during summer. Risk assessment of phthalates to aquatic life showed that there is no potential risk of DEP, DBP and BBP from effluents of treatment plants however risk quotient of DEHP was in the range of 27–73 in both seasons which indicate probable risk to aquatic organisms. Phthalate risk to human beings estimated by daily intake of phthalates was in the range of 0.3 ± 0.1 to 20 ± 0.7 ng/kg/d and far below their respective reference dosages, demonstrating the potential of these treatment plants to reduce the risk

  14. Free and total urinary phthalate metabolite concentrations among pregnant women from the Healthy Baby Cohort (HBC), China.

    Science.gov (United States)

    Zhu, Yingshuang; Wan, Yanjian; Li, Yuanyuan; Zhang, Bin; Zhou, Aifen; Cai, Zongwei; Qian, Zhengmin; Zhang, Chuncao; Huo, Wenqian; Huang, Kai; Hu, Jie; Cheng, Lu; Chang, Huailong; Huang, Zheng; Xu, Bing; Xia, Wei; Xu, Shunqing

    2016-03-01

    Total urinary phthalate metabolites (the free plus glucuronidated forms) have been frequently measured in the general population. However, data are limited on the free forms which may be more bioactive, especially for sensitive population such as pregnant women. Here the data gap was addressed by measuring concentrations of free and total forms of six phthalate metabolites in 293 urine samples from pregnant women at delivery, who were randomly selected from the prospective Healthy Baby Cohort (HBC), China. We observed detectable concentrations of the total amount of phthalate metabolites in all urine samples. The geometric mean (GM) urinary concentrations of free and total mono-butyl phthalate (MBP) (5.20, 54.49ng/mL) were the highest, followed by mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) (4.52, 7.27ng/mL). For most of phthalate metabolites, urinary concentrations were significantly higher in women who were nulliparous. Significantly higher concentrations of mono-ethyl phthalate (MEP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) were found in women who had higher educational level. To our knowledge, this is the first study to report the free and total forms of phthalate metabolites among pregnant women in China. The results suggest that exposure characteristics may be related to parity and education. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Comparative assessment of phthalate removal and risk in biological wastewater treatment systems of developing countries and small communities

    International Nuclear Information System (INIS)

    Gani, Khalid Muzamil; Kazmi, Absar Ahmad

    2016-01-01

    Phthalates are widely used in plastic and personnel care products. Being non-steroid endocrine disrupting compounds, their exposure have toxic effects on aquatic life and human health. The aim of this study was a comparative assessment of their fate and risk in full scale wastewater treatment along with influence of seasonal variations. Four priority phthalates, Diethylphthalate (DEP), Dibutylphthalate (DBP), Benzylbutyl phthalate (BBP) and Diethylhexyl phthalate (DEHP) were chosen for this study and wastewater treatment plants investigated were designed as nutrient removal based sequencing batch reactor (SBR), conventional activated sludge process (ASP) and up flow anaerobic sludge blanket (UASB) with polishing pond. Results showed that the main removal mechanism of phthalates was biotransformation with removal contribution of 74% in SBR, 65% in conventional ASP and 37% in UASB. Overall removal of phthalates was maximum in the treatment combination of UASB and pond (83%) followed by SBR (80%) and conventional ASP (74%). Seasonal influences on occurrence, removal and risk of these phthalates were also studied. The concentration of DEP, DBP and DEHP in untreated wastewater increased by 2, 7 and 2 μg/L, respectively in summer. However in sludge, only large molecular weight phthalates BBP and DEHP increased in winter by 3 mg/kg and 12 mg/kg, respectively. Seasonal variations in removal of phthalates were discrepant in each process with better removal during summer. Risk assessment of phthalates to aquatic life showed that there is no potential risk of DEP, DBP and BBP from effluents of treatment plants however risk quotient of DEHP was in the range of 27–73 in both seasons which indicate probable risk to aquatic organisms. Phthalate risk to human beings estimated by daily intake of phthalates was in the range of 0.3 ± 0.1 to 20 ± 0.7 ng/kg/d and far below their respective reference dosages, demonstrating the potential of these treatment plants to reduce the risk

  16. Semen phthalate metabolites, semen quality parameters and serum reproductive hormones: A cross-sectional study in China

    International Nuclear Information System (INIS)

    Wang, Yi-Xin; Zeng, Qiang; Sun, Yang; Yang, Pan; Wang, Peng; Li, Jin; Huang, Zhen; You, Ling; Huang, Yue-Hui; Wang, Cheng; Li, Yu-Feng; Lu, Wen-Qing

    2016-01-01

    Exposure to phthalates has been found to have adverse effects on male reproductive function in animals. However, the findings from human studies are inconsistent. Here we examined the associations of phthalate exposure with semen quality and reproductive hormones in a Chinese population using phthalate metabolite concentrations measured in semen as biomarkers. Semen (n = 687) and blood samples (n = 342) were collected from the male partners of sub-fertile couples who presented to the Reproductive Center of Tongji Hospital in Wuhan, China. Semen quality parameters and serum reproductive hormone levels were determined. Semen concentrations of 8 phthalate metabolites were assessed using high-performance liquid chromatography and tandem mass spectrometry. Associations of the semen phthalate metabolites with semen quality parameters and serum reproductive hormones were assessed using confounder-adjusted linear and logistic regression models. Semen phthalate metabolites were significantly associated with decreases in semen volume [mono-n-butyl phthalate (MBP), mono-(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP)], sperm curvilinear velocity [monobenzyl phthalate (MBzP), MEHP, the percentage of di-(2-ethylhexyl)-phthalate metabolites excreted as MEHP (%MEHP)], and straight-line velocity (MBzP, MEHP, %MEHP), and also associated with an increased percentage of abnormal heads and tails (MBzP) (all p for trend <0.05). These associations remained suggestive or significant after adjustment for multiple testing. There were no significant associations between semen phthalate metabolites and serum reproductive hormones. Our findings suggest that environmental exposure to phthalates may impair human semen quality. - Highlights: • We quantified 8 phthalate metabolites in the semen samples from 687 adult men. • We assessed associations of the metabolites with semen quality and serum hormones.

  17. Characteristics of diallyl phthalate resin as a fission track detector

    CERN Document Server

    Tsuruta, T

    1999-01-01

    Diallyl phthalate (DAP) resin plates were irradiated with fission fragments, and then etched in aqueous solution of KOH. Etched tracks were observed and counted by using an optical microscope. The detection efficiency of fission fragments was about 100% for both perpendicular and random incidence. DAP plates were insensitive to alpha particles and fast neutrons. These characteristics are suitable for detecting selected fission fragments, which coexist with alpha particles or fast neutrons. DAP plates are valuable for quantitative analysis of fissionable materials and neutron dosimetry. DAP and allyl diglycol carbonate (CR-39) were formed into copolymers in various ratios. The copolymers showed intermediate characteristics between DAP and CR-39. The fabrication of the copolymers made it possible to control the discrimination level for detection of heavy charged particles.

  18. Measurement of phthalates in small samples of mammalian tissue

    International Nuclear Information System (INIS)

    Acott, P.D.; Murphy, M.G.; Ogborn, M.R.; Crocker, J.F.S.

    1987-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP) is a phthalic acid ester that is used as a plasticizer in polyvinyl chloride products, many of which have widespread medical application. DEHP has been shown to be leached from products used for storage and delivery of blood transfusions during procedures such as plasmaphoresis, hemodialysis and open heart surgery. Results of studies in this laboratory have suggested that there is an association between the absorption and deposition of DEHP (and/or related chemicals) in the kidney and the acquired renal cystic disease (ACD) frequently seen in patients who have undergone prolonged dialysis treatment. In order to determine the relationship between the two, it has been necessary to establish a method for extracting and accurately quantitating minute amounts of these chemicals in small tissue samples. The authors have now established such a method using kidneys from normal rats and from a rat model for ACD

  19. Diallyl phthalate (DAP) solid state nuclear track detector

    CERN Document Server

    Koguchi, Y; Ashida, T; Tsuruta, T

    2003-01-01

    Diallyl phthalate (DAP) solid state nuclear track detector is suitable for detecting heavy ions such as fission fragments, because it is insensitive to right ions such as alpha particles and protons. Detection efficiency of fission tracks is about 100%, which is unaffected under conditions below 240degC lasting for 1h or below 1 MGy of gamma-ray irradiation. Optimum etching condition for the DAP detector for detection of fission fragments is 2-4 h using 30% KOH aqueous solution at 90degC or 8-15 min using PEW-65 solution at 60degC. DAP detector is useful in detecting induced fission tracks for dating of geology or measuring intense heavy ions induced by ultra laser plasma. The fabrication of copolymers of DAP and CR-39 makes it possible to control the discrimination level for detection threshold of heavy ions. (author)

  20. Toxic Effects of Di-2-ethylhexyl Phthalate: An Overview

    Directory of Open Access Journals (Sweden)

    Sai Sandeep Singh Rowdhwal

    2018-01-01

    Full Text Available Di-2-ethylhexyl phthalate (DEHP is extensively used as a plasticizer in many products, especially medical devices, furniture materials, cosmetics, and personal care products. DEHP is noncovalently bound to plastics, and therefore, it will leach out of these products after repeated use, heating, and/or cleaning of the products. Due to the overuse of DEHP in many products, it enters and pollutes the environment through release from industrial settings and plastic waste disposal sites. DEHP can enter the body through inhalation, ingestion, and dermal contact on a daily basis, which has raised some concerns about its safety and its potential effects on human health. The main aim of this review is to give an overview of the endocrine, testicular, ovarian, neural, hepatotoxic, and cardiotoxic effects of DEHP on animal models and humans in vitro and in vivo.

  1. Effects of dibutyl phthalate on lipid metabolism and drug metabolising enzyme system in rats

    International Nuclear Information System (INIS)

    Arakaki, Mitsuo; Ariyoshi, Toshihiko.

    1976-01-01

    Effects of dibutyl phthalate (DBP) on the liver constituents and the drug metabolizing enzyme system were investigated in rats. 1. In the experiments at a single oral dose of DBP (630 or 1260 mg/kg), the glycogen content was decreased only at the high dose, but no effects were observed on the contents of glycogen, triglyceride, microsomal protein and cytochromes, and on the activities of drug metabolizing enzymes. 2. In the repeated oral dose of DBP (630 or 1260 mg/kg/day) for 5 days, the ratio of liver weight to body weight was increased in both female and male rats, whereas the increases of cytochrome P-450 content and aniline hydroxylase activity were noted only in male rats. However, the contents of liver triglyceride, phospholipids, and cholesterol were unchanged. On the other hand, serum cholesterol content which showed the tendency to be decreased at the low dose was significantly decreased at the high dose. 3. In the incorporation of 1- 14 C-acetate into liver and serum lipids after repeated oral dose of DBP (630 mg/kg/day) for 5 days in male rats, the incorporation into triglyceride showed tendency to be increased, whereas the incorporation into cholesterol and cholesterol ester remained unchanged in vivo and in vitro. (auth.)

  2. Degradation kinetics of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge during composting

    International Nuclear Information System (INIS)

    Cheng, H.-F.; Kumar, Mathava; Lin, J.-G.

    2008-01-01

    The potential degradation of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge by composting was investigated using laboratory reactor at different operating conditions (E-1, E-2 and E-3). In all conditions, single stage thermophilic phase was observed within 2 days and almost, 60% of DEHP was degraded under this phase. At the end of composting, total DEHP degradation of more than 85% was observed in all conditions and total carbon reduction was 11.8% in E-1, 7.6% in E-2 and 10.8% in E-3. Similar trend was observed in the degradation of total nitrogen. The reduction of volatile solids (VS) in the composting reactors was 5.4% in E-1 (18 days), 5.5% in E-2 (12 days) and 4.3% in E-3 (18 days). The degradation kinetics of DEHP in thermophilic phase (including initial mesophilic phase) and the phase there after were determined by first order and fractional power kinetics, respectively. The significance of experimental parameters in DEHP degradation was assessed by Pearson correlation approach. Elevated temperature produced during composting was effective for the rapid degradation of DEHP from sewage sludge compared to mesophilic treatment

  3. Hydrogen safety

    International Nuclear Information System (INIS)

    Frazier, W.R.

    1991-01-01

    The NASA experience with hydrogen began in the 1950s when the National Advisory Committee on Aeronautics (NACA) research on rocket fuels was inherited by the newly formed National Aeronautics and Space Administration (NASA). Initial emphasis on the use of hydrogen as a fuel for high-altitude probes, satellites, and aircraft limited the available data on hydrogen hazards to small quantities of hydrogen. NASA began to use hydrogen as the principal liquid propellant for launch vehicles and quickly determined the need for hydrogen safety documentation to support design and operational requirements. The resulting NASA approach to hydrogen safety requires a joint effort by design and safety engineering to address hydrogen hazards and develop procedures for safe operation of equipment and facilities. NASA also determined the need for rigorous training and certification programs for personnel involved with hydrogen use. NASA's current use of hydrogen is mainly for large heavy-lift vehicle propulsion, which necessitates storage of large quantities for fueling space shots and for testing. Future use will involve new applications such as thermal imaging

  4. Hydrogen storage in carbon nanostruc

    NARCIS (Netherlands)

    Hirscher, M.; Becher, M.; Haluska, M.; Quintel, A.; Skakalova, V.; Choi, M.; Dettlaff-Weglikowska, U.; Roth, S.; Stepanek, I.; Bernier, P.; Leonhardt, A.; Fink, J.

    2002-01-01

    The paper gives a critical review of the literature on hydrogen storage in carbon nanostructures. Furthermore, the hydrogen storage of graphite, graphite nanofibers (GNFs), and single-walled carbon nanotubes (SWNTs) was measured by thermal desorption spectroscopy (TDS). The samples were ball milled

  5. One-Step Condensation and Hydrogenation of Furfural-Acetone Using Mixed and Single Catalyst Based on Ni/M-Oxide [M=Al; Mg

    Science.gov (United States)

    Ulfa, S. M.; Pramesti, I. N.; Mustafidah, H.

    2018-01-01

    Modification of furfural by condensation and hydrogenation reaction is a promising approach to produce higher alkane derivatives (C8-C13) as diesel fraction. This research investigated the catalytic activity of Ni/MgO as bifunctional catalyst compared with MgO-Ni/Al2O3 mixed catalyst for condensation-hydrogenation reaction. The Ni/MgO and Ni/Al2O3 with 20% Ni loading were prepared by wet impregnation methods using Ni(NO3)2.6H2O salt, calcined and reduced at 500°C. The catalyst performance was tested for one-step condensation-hydrogenation reaction using autoclave oil batch reactor. The reaction was conducted by reacting furfural and acetone in 1:1 ratio using water as solvent. Condensation reaction was performed at 100°C for 8 hours, followed by hydrogenation at 120°C during 7 hours. Analysis by gas chromatography showed that C=C double bond of furfurylidene acetone were successfully hydrogenated. Using Ni/MgO catalyst at 120°C, the products were identified as 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (2.68%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (trace amount). On the other hand, reaction using mixed catalyst, MgO-Ni/Al2O3 showed better activity over bifunctional Ni/MgO at the same reaction temperature. The products were identified as 4-(2-furanyl)-3-butan-2-one (27.30%); 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (3.82%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (1.11%). The impregnation of Ni on MgO decrease the physical properties of catalyst, confirmed by surface area analysis (SAA).

  6. Association of urinary phthalate metabolites concentrations with body mass index and waist circumference.

    Science.gov (United States)

    Amin, Mohammad Mehdi; Parastar, Saeed; Ebrahimpour, Karim; Shoshtari-Yeganeh, Bahareh; Hashemi, Majid; Mansourian, Marjan; Kelishadi, Roya

    2018-04-01

    This study aims to investigate the association of urinary concentration of phthalate metabolites with body mass index (BMI) and waist circumference (WC) in 2016 on 242 children and adolescents, aged 6-18 years living in Isfahan, Iran. Urinary concentration of mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono-methyl phthalate (MMP), mono (2-ethyl-5-exohexyl) phthalate (MEOHP), and mono (2-ethyl-5hydroxyhexyl) phthalate (MEHHP) metabolites were determined. For comparison of means, t test and to evaluate the association of analytes in different groups according to weight ANOVA was used. The correlation was applied to determine the association between phthalate metabolites with age, sex, WC, BMI, and BMI z-score. The univariate and multivariate regression models were used to determine the association of metabolites concentration with BMI z-score and WC. Mean (SD) BMI, BMI z-score and WC were 23.89 (4.41) kg/m 2 , 1.37 (1.3), and 82.37 (12.71) cm, respectively. There was a significant correlation between boys' age with BMI z-score (p value = 0.03) and WC (p value = 0.01), while the corresponding figures were not statistically significant in girls (p value = 0.48, and 0.4, respectively). Of the total population, 37 participants (15.3%) were obese. MMP, MBP, and MBzP metabolites were observed in all samples while MEHP, MEOHP, and MEHHP in 99.6, 95.86, and 96.28% of the studied population. Mean concentration of MMP (64.38 μg/L) and MBzP (268 μg/L) had the lowest and highest concentrations of metabolites, respectively. A significant relationship was observed among all studied metabolites and weight groups (p value ≤ 0.02). After adjustment for potential confounders, all metabolites (except MMP) showed a low-to-moderate positive and significant relationship with BMI z-score (β = 0.17-0.3). A weak to moderate positive and significant relationship was observed between all phthalate metabolites and WC (

  7. Age and sex-specific relationships between phthalate exposures and obesity in Chinese children at puberty.

    Directory of Open Access Journals (Sweden)

    Yunhui Zhang

    Full Text Available To examine the age and sex-specific associations of urine levels of six mono-phthalates with body size and fat distribution in Chinese children at puberty.Four hundred and ninety-three school-aged children (247 boys, 246 girls were recruited. Obesity related anthropometric indices were measured and body fat proportion (BF% was calculated. Spot urine samples were collected and phthalate monoesters were detected by an API 2000 electrospray triple quadrupole mass spectrometer (ESI-MS/MS. Associations between phthalate exposure and overweight/obesity measures and their trends were examined by multiple linear regression and Logistic regression analyses, respectively.Di-2-ethylhexyl phthalate (DEHP metabolites and monobutyl phthalate (MBP were found to be the most detectable chemicals. In 8-10 years (yrs group, concentrations of MEHP and MBP were significantly higher in girls than those in boys. However, concentrations of all phthalate monoesters, except for MEP and MEHP, in 11-13 yrs boys were significantly higher than those in girls. After adjusting for confounders including puberty onset, urinary concentrations of MBP and sum of low molecular-weight phthalate metabolites (∑LMP were positively associated with boys' obesity in a concentration-effect manner, while concentrations of MEHP, MEHHP and sum of DEHP metabolites (∑MEHP were negatively associated with girls' obesity. Associations between phthalate exposure levels and BMI z-score changes were age- and sex-specific in school-age children.There are age and sex-specific concentration-effect associations between phthalate exposure and fat distribution in Chinese children. Urinary phthalate levels in 11-13 yrs boys were about 30 percent higher than those in girls, and ∑MEHP levels in younger boys (10 yrs. Associations were positive for MBP and ∑LMP with both BMI z-score and fat distribution in boys >10 years of age, and negative for ∑MEHP with fat distribution in girls <10 years of age.

  8. Hydrogen Embrittlement

    Science.gov (United States)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  9. Adsorptive removal of phthalate ester (Di-ethyl phthalate) from aqueous phase by activated carbon: a kinetic study.

    Science.gov (United States)

    Venkata Mohan, S; Shailaja, S; Rama Krishna, M; Sarma, P N

    2007-07-19

    Adsorptive studies were carried out on Di-ethyl phthalate (DEP) removal from aqueous phase onto activated carbon. Batch sorption studies were performed and the results revealed that activated carbon demonstrated ability to adsorb DEP. Influence of varying experimental conditions such as DEP concentration, pH of aqueous solution, and dosage of adsorbent were investigated on the adsorption process. Sorption interaction of DEP onto activated carbon obeyed the pseudo second order rate equation. Experimental data showed good fit with both the Langmuir and Freundlich adsorption isotherm models. DEP sorption was found to be dependent on the aqueous phase pH and the uptake was observed to be greater at acidic pH.

  10. Hydrogen millennium

    International Nuclear Information System (INIS)

    Bose, T.K.; Benard, P.

    2000-05-01

    The 10th Canadian Hydrogen Conference was held at the Hilton Hotel in Quebec City from May 28 to May 31, 2000. The topics discussed included current drivers for the hydrogen economy, the international response to these drivers, new initiatives, sustainable as well as biological and hydrocarbon-derived production of hydrogen, defense applications of fuel cells, hydrogen storage on metal hydrides and carbon nanostructures, stationary power and remote application, micro-fuel cells and portable applications, marketing aspects, fuel cell modeling, materials, safety, fuel cell vehicles and residential applications. (author)

  11. Bisphenol A Is More Potent than Phthalate Metabolites in Reducing Pancreatic β-Cell Function

    Directory of Open Access Journals (Sweden)

    Nina Mickelson Weldingh

    2017-01-01

    Full Text Available Bisphenol A (BPA and phthalates are common environmental contaminants that have been proposed to influence incidence and development of types 1 and 2 diabetes. Thus, effects of BPA and three phthalate metabolites (monoisobutyl phthalate (MiBP, mono-n-butyl phthalate (MnBP, and mono-(2-ethylhexyl phthalate (MEHP were studied in the pancreatic β-cell line INS-1E, after 2–72 h of exposure to 5–500 μM. Three endpoints relevant to accelerated development of types 1 or 2 diabetes were investigated: β-cell viability, glucose-induced insulin secretion, and β-cell susceptibility to cytokine-induced cell death. BPA and the phthalate metabolites reduced cellular viability after 72 h of exposure, with BPA as the most potent chemical. Moreover, BPA, MEHP, and MnBP increased insulin secretion after 2 h of simultaneous exposure to chemicals and glucose, with potency BPA > MEHP > MnBP. Longer chemical exposures (24–72 h showed no consistent effects on glucose-induced insulin secretion, and none of the environmental chemicals affected susceptibility to cytokine-induced cell death. Overall, BPA was more potent than the investigated phthalate metabolites in affecting insulin secretion and viability in the INS-1E pancreatic β-cells. In contrast to recent literature, concentrations with relevance to human exposures (1–500 nM did not affect the investigated endpoints, suggesting that this experimental model displayed relatively low sensitivity to environmental chemical exposure.

  12. Prenatal phthalate exposure and 8-isoprostane among Mexican-American children with high prevalence of obesity.

    Science.gov (United States)

    Tran, V; Tindula, G; Huen, K; Bradman, A; Harley, K; Kogut, K; Calafat, A M; Nguyen, B; Parra, K; Ye, X; Eskenazi, B; Holland, N

    2017-04-01

    Oxidative stress has been linked to many obesity-related conditions among children including cardiovascular disease, diabetes mellitus and hypertension. Exposure to environmental chemicals such as phthalates, ubiquitously found in humans, may also generate reactive oxygen species and subsequent oxidative stress. We examined longitudinal changes of 8-isoprostane urinary concentrations, a validated biomarker of oxidative stress, and associations with maternal prenatal urinary concentrations of phthalate metabolites for 258 children at 5, 9 and 14 years of age participating in a birth cohort residing in an agricultural area in California. Phthalates are endocrine disruptors, and in utero exposure has been also linked to altered lipid metabolism, as well as adverse birth and neurodevelopmental outcomes. We found that median creatinine-corrected 8-isoprostane concentrations remained constant across all age groups and did not differ by sex. Total cholesterol, systolic and diastolic blood pressure were positively associated with 8-isoprostane in 14-year-old children. No associations were observed between 8-isoprostane and body mass index (BMI), BMI Z-score or waist circumference at any age. Concentrations of three metabolites of high molecular weight phthalates measured at 13 weeks of gestation (monobenzyl, monocarboxyoctyl and monocarboxynonyl phthalates) were negatively associated with 8-isoprostane concentrations among 9-year olds. However, at 14 years of age, isoprostane concentrations were positively associated with two other metabolites (mono(2-ethylhexyl) and mono(2-ethyl-5-carboxypentyl) phthalates) measured in early pregnancy. Longitudinal data on 8-isoprostane in this pediatric population with a high prevalence of obesity provides new insight on certain potential cardiometabolic risks of prenatal exposure to phthalates.

  13. Recycling of plastic waste: Presence of phthalates in plastics from households and industry.

    Science.gov (United States)

    Pivnenko, K; Eriksen, M K; Martín-Fernández, J A; Eriksson, E; Astrup, T F

    2016-08-01

    Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large volumes and are commonly used as plasticisers in plastics manufacturing. Potential impacts on human health require restricted use in selected applications and a need for the closer monitoring of potential sources of human exposure. Although the presence of phthalates in a variety of plastics has been recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP had the highest frequency of detection in the samples analysed, with 360μg/g, 460μg/g and 2700μg/g as the maximum measured concentrations, respectively. Among other, statistical analysis of the analytical results suggested that phthalates were potentially added in the later stages of plastic product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications is recommended if recycled plastics are to be used as raw material in production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Phthalate metabolites related to infertile biomarkers and infertility in Chinese men.

    Science.gov (United States)

    Liu, Liangpo; Wang, Heng; Tian, Meiping; Zhang, Jie; Panuwet, Parinya; D'Souza, Priya Esilda; Barr, Dana Boyd; Huang, Qingyu; Xia, Yankai; Shen, Heqing

    2017-12-01

    Although in vitro and in vivo laboratory studies have demonstrated androgen and anti-androgen effects on male reproduction from phthalate exposures, human studies still remain inconsistent. Therefore, a case-control study (n = 289) was conducted to evaluate the associations between phthalate exposures, male infertility risks, and changes in metabolomic biomarkers. Regional participants consisted of fertile (n = 150) and infertile (n = 139) males were recruited from Nanjing Medical University' affiliated hospitals. Seven urinary phthalate metabolites were measured using HPLC-MS/MS. Associations between levels of phthalate metabolites, infertility risks, and infertility-related biomarkers were statistically evaluated. MEHHP, one of the most abundant DEHP oxidative metabolites was significantly lower in cases than in controls (p = 0.039). When using the 1st quartile range as a reference, although statistically insignificant for odds ratios (ORs) of the 2nd, 3rd, and 4th quartiles (OR (95% CI) = 1.50 (0.34-6.48), 0.70 (0.14-3.52) and 0.42 (0.09-2.00), respectively), the MEHHP dose-dependent trend of infertility risk expressed as OR decreased significantly (p = 0.034). More interestingly, most of the phthalate metabolites, including MEHHP, were either positively associated with fertile prevention metabolic biomarkers or negatively associated with fertile hazard ones. Phthalate metabolism, along with their activated infertility-related biomarkers, may contribute to a decreased risk of male infertility at the subjects' ongoing exposure levels. Our results may be illustrated by the low-dose related androgen effect of phthalates and can improve our understanding of the controversial epidemiological results on this issue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Dose–response analysis of phthalate effects on gene expression in rat whole embryo culture

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Joshua F. [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Verhoef, Aart; Beelen, Vincent A. van; Pennings, Jeroen L.A. [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H., E-mail: aldert.piersma@rivm.nl [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht (Netherlands)

    2012-10-01

    The rat postimplantation whole embryo culture (WEC) model serves as a potential screening tool for developmental toxicity. In this model, cultured rat embryos are exposed during early embryogenesis and evaluated for morphological effects. The integration of molecular-based markers may lead to improved objectivity, sensitivity and predictability of WEC in assessing developmental toxic properties of compounds. In this study, we investigated the concentration-dependent effects of two phthalates differing in potency, mono(2-ethylhexyl) phthalate (MEHP) and monomethyl phthalate (MMP, less toxic), on the transcriptome in WEC to examine gene expression in relation with dysmorphogenesis. MEHP was more potent than MMP in inducing gene expression changes as well as changes on morphology. MEHP induced significant enrichment of cholesterol/lipid/steroid (CLS) metabolism and apoptosis pathways which was associated with developmental toxicity. Regulation of genes within CLS metabolism pathways represented the most sensitive markers of MEHP exposure, more sensitive than classical morphological endpoints. As shown in direct comparisons with toxicogenomic in vivo studies, alterations in the regulation of CLS metabolism pathways has been previously identified to be associated with developmental toxicity due to phthalate exposure in utero. Our results support the application of WEC as a model to examine relative phthalate potency through gene expression and morphological responses. Additionally, our results further define the applicability domain of the WEC model for developmental toxicological investigations. -- Highlights: ► We examine the effect of two phthalates on gene expression and morphology in WEC. ► MEHP is more potent than MMP in inducing gene expression changes and dysmorphogenesis. ► MEHP significantly disrupts cholesterol metabolism pathways in a dose-dependent manner. ► Specific phthalate-related mechanisms in WEC are relevant to mechanisms in vivo.

  16. Role of Oxidative Stress in Male Reproductive Dysfunctions with Reference to Phthalate Compounds.

    Science.gov (United States)

    Sedha, Sapna; Kumar, Sunil; Shukla, Shruti

    2015-11-14

    A wide variety of environmental chemicals/xenobiotics including phthalates have been shown to cause oxidative stress targeting the endocrine system and cause reproductive anomalies. The present review describes various issues by oxidative stress causing male reproductive dysfunctions. Here in this review, the importance and role of phthalate compounds in male reproductive dysfunction has been well documented. One class of environmental endocrine disruptors is phthalates. Phthalate compounds are mostly used as plasticizers, which increase the flexibility, durability, longevity, and etc. of the plastics. Large-scale use of plastic products in our daily life as well as thousands of workers engaged in the manufacture of plastic and plastic products and recycling plastic industry are potentially exposed to these chemicals. Further, general population as well as vulnerable groups i.e. children and pregnant women are also exposed to these chemicals. Phthalates are among wide variety of environmental toxicants capable of compromising male fertility by inducing a state of oxidative stress in the testes. They may also generate reactive oxygen species (ROS) that may affect various physiological and reproductive functions. The available data points out that phthalate compounds may also induce oxidative stress in the male reproductive organs mainly testis and epididymis. They impair spermatogenic process by inducing oxidative stress and apoptosis in germ cells or target sertoli cells and thereby hamper spermatogenesis. They also impair the Leydig cell function by inducing ROS, thereby decreasing the levels of steroidogenic enzymes. Thus in utero and postnatal exposure to phthalate compounds might lead to decreased sperm count and various other reproductive anomalies in the young male.

  17. Persistent Associations between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years.

    Directory of Open Access Journals (Sweden)

    Pam Factor-Litvak

    Full Text Available Prior research reports inverse associations between maternal prenatal urinary phthalate metabolite concentrations and mental and motor development in preschoolers. No study evaluated whether these associations persist into school age.In a follow up of 328 inner-city mothers and their children, we measured prenatal urinary metabolites of di-n-butyl phthalate (DnBP, butylbenzyl phthalate (BBzP, di-isobutyl phthalate (DiBP, di-2-ethylhexyl phthalate and diethyl phthalate in late pregnancy. The Wechsler Intelligence Scale for Children, 4th edition was administered at child age 7 years and evaluates four areas of cognitive function associated with overall intelligence quotient (IQ.Child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP and DiBP: b = -2.69 (95% confidence interval [CI] = -4.33, -1.05 and b = -2.69 (95% CI = -4.22, -1.16 per log unit increase. Among children of mothers with the highest versus lowest quartile DnBP and DiBP metabolite concentrations, IQ was 6.7 (95% CI = 1.9, 11.4 and 7.6 (95% CI = 3.2, 12.1 points lower, respectively. Associations were unchanged after control for cognition at age 3 years. Significant inverse associations were also seen between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP and child perceptual reasoning.Maternal prenatal urinary metabolite concentrations measured in late pregnancy of DnBP and DiBP are associated with deficits in children's intellectual development at age 7 years. Because phthalate exposures are ubiquitous and concentrations seen here within the range previously observed among general populations, results are of public health significance.

  18. Single step synthesis of gold-amino acid composite, with the evidence of the catalytic hydrogen atom transfer (HAT) reaction, for the electrochemical recognition of Serotonin

    Science.gov (United States)

    Choudhary, Meenakshi; Siwal, Samarjeet; Nandi, Debkumar; Mallick, Kaushik

    2016-03-01

    A composite architecture of amino acid and gold nanoparticles has been synthesized using a generic route of 'in-situ polymerization and composite formation (IPCF)' [1,2]. The formation mechanism of the composite has been supported by a model hydrogen atom (H•≡H++e-) transfer (HAT) type of reaction which belongs to the proton coupled electron transfer (PCET) mechanism. The 'gold-amino acid composite' was used as a catalyst for the electrochemical recognition of Serotonin.

  19. A mixture of five phthalate diesters cummulatively inhibit fetal testicular testoserone production in a manner consisent with their predicted reporduction toxicity in the Sprague Dawley rat.

    Science.gov (United States)

    Phthalate diesters are commonly-used plasticizers in intravenous bags, plastic food wrap and children’s toys, and the metabolites of multiple phthalates are detected in humans. In utero exposure to certain phthalates during sexual differentiation causes male reproductive tract m...

  20. Simple inorganic complexes but intricate hydrogen bonding ...

    Indian Academy of Sciences (India)

    Administrator

    We are interested in obtaining single crystals of metal-opda complexes because their crystal structures would show complex hydrogen bonding network due to the presence of. –NH2 groups in the opda ligand (hydrogen bonding donor sites) and inorganic anions having mostly oxo groups (hydrogen bonding acceptor sites) ...