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Sample records for alkyl ammonium ion

  1. Organic Modification of a Layered Silicate by Co-Ion Exchange of an Alkyl Ammonium and a Mono-Protonated Diamine

    NASA Technical Reports Server (NTRS)

    Campbell, Sandi G. (Inventor)

    2004-01-01

    Co-Ion exchange of the interlayer cations of a layered silicate with a mono-protonated aromatic diamine and an alkyl ammonium ion into the silicate galleries. The presence of the alkyl ammonium ion provides low oligomer melt viscosity during processing. The presence of the diamine allows chemical reaction between the silicate surface modification and the monomers. This reaction strengthens the polymer silicate interface, and ensures irreversible separation of the individual silicate layers. Improved polymer thermal oxidative stability and mechanical properties are obtained.

  2. 40 CFR 721.10430 - Tetra alkyl ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tetra alkyl ammonium salt (generic... Specific Chemical Substances § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance and... ammonium salt (PMN P-97-823) is subject to reporting under this section for the significant new...

  3. 40 CFR 721.10430 - Tetra alkyl ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tetra alkyl ammonium salt (generic... Specific Chemical Substances § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance and... ammonium salt (PMN P-97-823) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  5. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  6. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  7. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  8. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  9. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  10. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  11. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  12. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  13. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  14. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  15. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  16. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  17. Modeling of alkyl quaternary ammonium cations intercalated into montmorillonite lattice

    SciTech Connect

    Daoudi, El Mehdi; Boughaleb, Yahia; El Gaini, Layla; Meghea, Irina; Bakasse, Mina

    2013-05-15

    Highlights: ► The modification of montmorillonites by three surfactants increases the basal spacing. ► The model proposed show a bilayer conformation for the surfactant ODTMA. ► The DODMA and TOMA surfactants adopt a paraffin type arrangement. ► Behavior of surfactants in interlayer space was confirmed by TGA and ATR analysis. - Abstract: The objective of this work was to study the conformation of the quaternary ammonium cations viz., octadecyl trimethyl ammonium (ODTMA), dioctadecyl dimethyl ammonium (DMDOA) and trioctadecyl methyl ammonium (TOMA) intercalated within montmorillonite. The modified montmorillonite was characterized by X-ray diffraction in small angle (SAXS), thermal analysis (TGA) and infrared spectroscopy of attenuated total reflection (ATR). The modification of organophilic montmorillonites by the three surfactants ODTMA, DMDOA and TOMA increases the basal spacing from their respective intercalated distances of 1.9 nm, 2.6 nm and 3.4 nm respectively. The increase in the spacing due to the basic organic modification was confirmed by the results of thermal analysis (TGA) and infrared spectroscopy (ATR), and also supported by theoretical calculations of longitudinal and transversal chain sizes of these alkyl quaternary ammonium cations.

  18. Extraction of urea and ammonium ion

    NASA Technical Reports Server (NTRS)

    Anselmi, R. T.; Husted, R. R.; Schulz, J. R.

    1977-01-01

    Water purification system keeps urea and ammonium ion concentration below toxic limits in recirculated water of closed loop aquatic habitat. Urea is first converted to ammonium ions and carbon dioxide by enzygmatic action. Ammonium ions are removed by ion exchange. Bioburden is controlled by filtration through 0.45 micron millipore filters.

  19. Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy Tetraglucosylcalix[4]arene

    NASA Astrophysics Data System (ADS)

    Torvinen, Mika; Kalenius, Elina; Sansone, Francesco; Casnati, Alessandro; Jänis, Janne

    2012-02-01

    The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalix[4]arene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.

  20. Alkyl ammonium cation stabilized biocidal polyiodides with adaptable high density and low pressure.

    PubMed

    He, Chunlin; Parrish, Damon A; Shreeve, Jean'ne M

    2014-05-26

    The effective application of biocidal species requires building the active moiety into a molecular back bone that can be delivered and decomposed on demand under conditions of low pressure and prolonged high-temperature detonation. The goal is to destroy storage facilities and their contents while utilizing the biocidal products arising from the released energy to destroy any remaining harmful airborne agents. Decomposition of carefully selected iodine-rich compounds can produce large amounts of the very active biocides, hydroiodic acid (HI) and iodine (I2). Polyiodide anions, namely, I3(-), I5(-), which are excellent sources of such biocides, can be stabilized through interactions with large, symmetric cations, such as alkyl ammonium salts. We have designed and synthesized suitable compounds of adaptable high density up to 3.33 g cm(-3) that are low-pressure polyiodides with various alkyl ammonium cations, deliverable iodine contents of which range between 58.0-90.9%.

  1. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine (PMN...

  2. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine (PMN...

  3. Thermal and optical studies of some di-methyl-di-alkyl ammonium bromides

    NASA Astrophysics Data System (ADS)

    Witko, Waclaw; Godlewska, Malgorzata; Dynarowicz, Patrycja

    1998-01-01

    Phase situation of homologous series of di-alkyl-di-methyl ammonium bromides represented by the general formula: 2CnN+2C1Br-, with n equals 10, 12, 14, 16, 18, was investigated by means of differential scanning calorimetry and optical microscopy methods in the temperature range 20-180 degrees C. A more complex polymorphism as already reported was detected. All the compounds studied show at least tow anomalies on the DSC curves. The high-temperature phase which appears below the isotropic phase has lancet-like dendritic texture which can be attributed to SmB phase. The enthalpy changes at the transitions were calculated.

  4. Ammonium Ion Currents in the Squid Giant Axon

    PubMed Central

    Binstock, Leonard; Lecar, Harold

    1969-01-01

    Voltage-clamp studies on intact and internally perfused squid giant axons demonstrate that ammonium can substitute partially for either sodium or potassium. Ammonium carries the early transient current with 0.3 times the permeability of sodium and it carries the delayed current with 0.3 times the potassium permeability. The conductance changes observed in voltage clamp show approximately the same time course in ammonium solutions as in the normal physiological solutions. These ammonium ion permeabilities account for the known effects of ammonium on nerve excitability. Experiments with the drugs tetrodotoxin (TTX) and tetraethyl ammonium chloride (TEA) demonstrate that these molecules block the early and late components of the current selectively, even when both components are carried by the same ion, ammonium. PMID:5767336

  5. Distribution coefficients of purine alkaloids in water-ammonium sulfate-alkyl acetate-dialkyl phthalate systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Krivosheeva, O. A.; Mokshina, N. Ya.

    2012-12-01

    The distribution of purine alkaloids (caffeine, theobromine, theophylline) was studied in the systems: alkyl acetates-dialkyl phtalate-salting-out agent (ammonium sulfate). The quantitative characteristics of the extraction-distribution coefficients ( D) and the degree of extraction ( R, %) are calculated. The relationships between the distribution coefficients of alkaloids and the length of the hydrocarbon radical in the molecule of alkyl acetate (dialkyl phtalate) are determined. The possibility of predicting the distribution coefficients is demonstrated.

  6. Contribution of ammonium ions to the lethality and antimetamorphic effects of ammonium perchlorate.

    PubMed

    Goleman, Wanda L; Carr, James A

    2006-04-01

    Ammonium perchlorate (AP) is a widespread military waste product in the United States and is a potent thyroid function disruptor in all vertebrates tested thus far. To determine the relative contribution of ammonium ions to the toxicity of AP, we exposed embryonic and larval Xenopus laevis to various concentrations of sodium perchlorate (SP) or ammonium chloride (AC). Ammonium perchlorate was significantly more lethal than SP; 5-d LC50s were 83 and 2,780 mg/L, respectively. To determine whether ammonium ions contribute to the antithyroid effects of AP, we exposed embryonic and larval X. laevis to two sublethal, environmentally relevant concentrations of AP or identical concentrations of AC or SP. At the smaller concentration, only AP delayed metamorphosis and reduced hindlimb growth. Sodium perchlorate and AP, but not AC, prevented metamorphosis and reduced hindlimb growth at the greater concentration. Although AP was slightly more effective in reducing outward manifestations of thyroid disruption, both perchlorate salts, unlike AC, caused profound histopathologic changes in the thyroid. Exposure to the higher concentration of either perchlorate salt produced a feminizing effect, resulting in a skewed sex ratio. We conclude that ammonium ions contribute significantly to the toxicity of AP but not to the direct antithyroid effects of perchlorate.

  7. Ammonium and sulfate ion release of histamine from lung fragments.

    PubMed

    Charles, J M; Menzel, D B

    1975-06-01

    In vitro studies with guinea pig lung fragments incubated with 10- to 200-mM concentrations of ammonium ion demonstrated the release of substanial quantities of histamine. Of the anions tested with ammonium ion, sulfate was the most potent, while nitrate and acetate ions were of intermediate potency and chloride was less potent. An osmotic effect is unlikely since equal concentrations of sodium chloride failed to release histamine. Isoproterenol, known to decrease anaphylactic histamine release, and acetycholine, known to increase histamine release, had no effect on the ammonium sulfate-mediated release of histamine. N-6 2'-O-Dibutyryladenosine 3',5' monophosphate (dibutyryl c-AMP) was also ineffective. These studies suggest that the inhalation irritation associated with certain sulfate and other salts, may be a function of their ability to release histamine in the presence of amonium ion.

  8. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...(hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479 Protection of Environment..., tris(hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant new uses...(hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No. 308074-73-9) is subject to reporting...

  9. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...(hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479 Protection of Environment..., tris(hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant new uses...(hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No. 308074-73-9) is subject to reporting...

  10. Antihydrophobic cosolvent effects for alkylation reactions in water solution, particularly oxygen versus carbon alkylations of phenoxide ions.

    PubMed

    Breslow, Ronald; Groves, Kevin; Mayer, M Uljana

    2002-04-10

    Antihydrophobic cosolvents such as ethanol increase the solubility of hydrophobic molecules in water, and they also affect the rates of reactions involving hydrophobic surfaces. In simple reactions of hydrocarbons, such as the Diels-Alder dimerization of 1,3-cyclopentadiene, the rate and solubility data directly reflect the geometry of the transition state, in which some hydrophobic surface becomes hidden. In reactions involving polar groups, such as alkylations of phenoxide ions or S(N)1 ionizations of alkyl halides, cosolvents in water can have other effects as well. However, solvation of hydrophobic surfaces is still important. By the use of structure-reactivity relationships, and comparing the effects of ethanol and DMSO as solvents, it has been possible to sort out these effects. The conclusions are reinforced by an ab initio computer model for hydrophobic solvation. The result is a sensible transition state for phenoxide ion as a nucleophile, using its oxygen n electrons to avoid loss of conjugation. The geometry of alkylation of aniline is very different, involving packing (stacking) of the aniline ring onto the phenyl ring of a benzyl group in the benzylation reaction. The alkylation of phenoxide ions by benzylic chlorides can occur both at the phenoxide oxygen and on ortho and para positions of the ring. Carbon alkylation occurs in water, but not in nonpolar organic solvents, and it is observed only when the phenoxide has at least one methyl substituent ortho, meta, or para. The effects of phenol substituents and of antihydrophobic cosolvents on the rates of the competing alkylation processes indicate that in water the carbon alkylation involves a transition state with hydrophobic packing of the benzyl group onto the phenol ring. The results also support our conclusion that oxygen alkylation uses the n electrons of the phenoxide oxygen as the nucleophile and does not have hydrophobic overlap in the transition state. The mechanisms and explanations for

  11. Preferential uptake of ammonium ions by zinc ferrocyanide

    NASA Technical Reports Server (NTRS)

    Braterman, P. S.; Arrhenius, G.; Hui, S.; Paplawsky, W.; Miller, S. L. (Principal Investigator)

    1995-01-01

    The concentration of ammonia from dilute aqueous solution could have facilitated many prebiotic reactions. This may be especially true if this concentration involves incorporation into an organized medium. We have shown that (unlike iron(III) ferrocyanide) zinc ferrocyanide,Zn2Fe(CN)6 xH2O, preferentially takes up ammonium ions from 0.01 M NH4Cl to give the known material Zn3(NH4)2[Fe(CN)6]2 xH2O, even in the presence of 0.01 M KCl. KCl alone gave Zn3K2[Fe(CN)6]2 xH2O. Products were characterized by elemental (CHN) analysis and powder X-ray diffraction (XRD). We attribute the remarkable specificity for the ammonium ion to the open framework of the product, which offers enough space for hydrogen-bonded ammonium ions, and infer that other inorganic materials with internal spaces rich in water may show a similar preference.

  12. Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

  13. Molecular recognition of organic ammonium ions in solution using synthetic receptors

    PubMed Central

    Späth, Andreas

    2010-01-01

    Summary Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation–π interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications. PMID:20502608

  14. A Systematic Investigation of Quaternary Ammonium Ions as Asymmetric Phase Transfer Catalysts. Application of Quantitative Structure Activity/Selectivity Relationships

    PubMed Central

    Denmark, Scott E.; Gould, Nathan D.; Wolf, Larry M.

    2011-01-01

    While the synthetic utility of asymmetric phase transfer catalysis continues to expand, the number of proven catalyst types and design criteria remains limited. At the origin of this scarcity is a lack in understanding of how catalyst structural features affect the rate and enantioselectivity of phase transfer catalyzed reactions. Described in this paper is the development of quantitative structure-activity relationships (QSAR) and -selectivity relationships (QSSR) for the alkylation of a protected glycine imine with libraries of quaternary ammonium ion catalysts. Catalyst descriptors including ammonium ion accessibility, interfacial adsorption affinity, and partition coefficient were found to correlate meaningfully with catalyst activity. The physical nature of the descriptors was rationalized through differing contributions of the interfacial and extraction mechanisms to the reaction under study. The variation in the observed enantioselectivity was rationalized employing a comparative molecular field analysis (CoMFA) using both the steric and electrostatic fields of the catalysts. A qualitative analysis of the developed model reveals preferred regions for catalyst binding to afford both configurations of the alkylated product. PMID:21446723

  15. The selectivity of different external binding sites for quaternary ammonium ions in cloned potassium channels.

    PubMed

    Jarolimek, W; Soman, K V; Brown, A M; Alam, M

    1995-09-01

    Tetraethylammonium (TEA) is thought to be the most effective quaternary ammonium (QA) ion blocker at the external site of K+ channels, and small changes to the TEA ion reduce its potency. To examine the properties of the external QA receptor, we applied a variety of QA ions to excised patches from human embryonic kidney cells or Xenopus oocytes transfected with the delayed rectifying K+ channels Kv 2.1 and Kv 3.1. In outside-out patches of Kv 3.1, the relative potencies were TEA > tetrapropylammonium (TPA) > tetrabutylammonium (TBA). In contrast to Kv 3.1, the relative potencies in Kv 2.1 were TBA > TEA > TPA. In Kv 3.1 and Kv 2.1, external tetrapentylammonium (TPeA) blocked K+ currents in a fast, reversible and, in contrast to TEA, time-dependent manner. The external binding of TPeA appeared to be voltage independent, unlike the effects of TPeA applied to inside-out patches. External n-alkyl-triethylammonium compounds (C8, C10 chain length) had a lower affinity than TEA in Kv 3.1, but a higher affinity than TEA in Kv 2.1. In Kv 3.1, the decrease in QA affinity was large when one or two methyl groups were substituted for ethyl groups in TEA, but minor when propyl groups replaced ethyl groups. Changes in the free energy of binding could be correlated to changes in the free energy of hydration of TEA derivatives calculated by continuum methodology. These results reveal a substantial hydrophobic component of external QA ion binding to Kv 2.1, and to a lesser degree to Kv 3.1, in addition to the generally accepted electrostatic interactions. The chain length of hydrophobic TEA derivatives affects the affinity for the hydrophobic binding site, whereas the hydropathy of QA ions determines the electrostatic interaction energy.

  16. [Determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Zhu, Feng

    2015-01-01

    A method has been developed for the determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds (DHTDMAC) in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry. (UPLC-MS/MS). The samples were extracted and diluted with acidified methanol by 5% (v/v) formic acid under ultrasonic assistance. The separation was performed on an Eclipse Plus C18 column (50 mm x 2.1 mm, 1.8 microm) using 0.1% (v/v) formic acid solution and methanol as the mobile phases. Identification and quantification were achieved by UPLC-MS/MS with electrospray ionization (ESI) source in positive ion mode and multiple reaction monitoring (MRM) mode. The results indicated that the calibration curve of DHTDMAC showed good linear relationship between peak area and mass concentration in the range of 10-280 microg/L with the correlation coefficient (r2) of 0.9991. The limit of detection (LOD, S/N=3) and the limit of quantification (LOQ, S/N= 10) of this method were 3 mg/kg and 10 mg/kg, respectively. The average recoveries from three typical textile auxiliary matrices including dispersant, antistatic agent and fabric softener, at three spiked levels were in the range of 97.2%-108.3% with the relative standard deviations (RSDs) of 1.5%-4.6%. The method is sensitive, accurate, simple and effective for the analysis of DHTDMAC in textile auxiliaries.

  17. AMMONIUM AND FORMATE IONS IN INTERSTELLAR ICE ANALOGS

    SciTech Connect

    Galvez, Oscar; Mate, Belen; Herrero, Victor J.; Escribano, Rafael

    2010-11-20

    The so-called hyperquenching technique has been applied to generate water ices containing ammonium and formate ions by sudden freezing of droplets of NH{sub 4}Cl, NH{sub 4}COOH, and NaCOOH solutions. Salt deposits were obtained after heating the ices to 210 K to sublimate all water content. All stages are controlled by IR transmission spectroscopy. The NH{sub 4} {sup +} bands are very much broadened and smeared in the frozen droplets, but stand out strongly when water is eliminated. This fact hints toward the difficulty in ascertaining the presence of this species in astrophysical water-containing ices. Vapor-deposited ices of NH{sub 3}/HCOOH and H{sub 2}O/NH{sub 3}/HCOOH mixtures have also been studied for comparison. HCOO{sup -} and NH{sub 4} {sup +} ions are found to be formed in small proportion even at the lowest temperature, 14 K. By thermal processing, their IR bands become stronger, and at 210 K, after water sublimation, they yield IR spectra similar to those obtained from hyperquenched samples. The observations are interpreted in terms of the varying ion arrangement within the solids along the warming process. A direct comparison to laboratory spectra of irradiated samples, as performed by other groups, is not straightforward.

  18. Evidence of ammonium ion-exchange properties of natural bentonite and application to ammonium detection.

    PubMed

    Zazoua, A; Kazane, I; Khedimallah, N; Dernane, C; Errachid, A; Jaffrezic-Renault, N

    2013-12-01

    Ammonium exchange with hybrid PVC-bentonite (mineral montmorillonite clay) thin film was revealed using FTIR spectroscopy, EDX, cyclic voltammetry and electrochemical impedance spectroscopy. The effect of ammonium exchange on the charge transfer resistance of PVC-bentonite hybrid thin film was attributed to a modification of the intersheet distance and hydration of bentonite crystals. The obtained impedimetric ammonium sensor shows a linear range of detection from 10(-4)M to 1M and a detection limit around 10(-6)M.

  19. Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

    DOEpatents

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2016-03-15

    Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

  20. Conductometric determination of ammonium ion with a mobile drop.

    PubMed

    Jaikang, Pheeraya; Grudpan, Kate; Kanyanee, Tinakorn

    2015-01-01

    A mobile drop based approach was utilized for the conductometric determination of aqueous ammonium ion. A liquid drop was manipulated by gravity to remain or move out of a conductivity measurement zone located on a hydrophobic path. A dilute sulfuric acid drop functioned as a micro gas absorber. Gaseous NH3 was liberated from a sample containing NH4(+) by adding NaOH and purged to flow over the absorber drop. As H(+) in the absorber drop was converted to NH4(+), the conductivity decreased. The rate of the conductivity decrease thus ultimately depended on the NH4(+) concentration in the sample. While the sample could be complex, the liberation of NH3 gas essentially freed the analyte of interest from the matrix and allowed the use of an otherwise nonselective detector. The system was applied to the determination of NH4(+) in some natural waters without prior filtration; the results agreed well with those from a manual indophenol blue method. The approach exhibited a limit of detection (LOD) of 5 μM and a relative standard deviation (RSD) of<5%. The mobile drop gave a constant volume of the gas absorbing solution and provided a cost-effective and simple analytical platform.

  1. Adsorption of ammonium ion by coconut shell-activated carbon from aqueous solution: kinetic, isotherm, and thermodynamic studies.

    PubMed

    Boopathy, Ramasamy; Karthikeyan, Sekar; Mandal, Asit Baran; Sekaran, Ganesan

    2013-01-01

    Ammonium ions are one of the most encountered nitrogen species in polluted water bodies. High level of ammonium ion in aqueous solution imparts unpleasant taste and odor problems, which can interfere with the life of aquatics and human population when discharged. Many chemical methods are developed and being used for removal of ammonium ion from aqueous solution. Among various techniques, adsorption was found to be the most feasible and environmentally friendly with the use of natural-activated adsorbents. Hence, in this study, coconut shell-activated carbon (CSAC) was prepared and used for the removal of ammonium ion by adsorption techniques. Ammonium chloride (analytical grade) was purchased from Merck Chemicals for adsorption studies. The CSAC was used to adsorb ammonium ions under stirring at 100 rpm, using orbital shaker in batch experiments. The concentration of ammonium ion was estimated by ammonia distillate, using a Buchi distillation unit. The influence of process parameters such as pH, temperature, and contact time was studied for adsorption of ammonium ion, and kinetic, isotherm models were validated to understand the mechanism of adsorption of ammonium ion by CSAC. Thermodynamic properties such as ∆G, ∆H, and ∆S were determined for the ammonium adsorption, using van't Hoff equation. Further, the adsorption of ammonium ion was confirmed through instrumental analyses such as SEM, XRD, and FTIR. The optimum conditions for the effective adsorption of ammonium ion onto CSAC were found to be pH 9.0, temperature 283 K, and contact time 120 min. The experimental data was best followed by pseudosecond order equation, and the adsorption isotherm model obeyed the Freundlich isotherm. This explains the ammonium ion adsorption onto CSAC which was a multilayer adsorption with intraparticle diffusion. Negative enthalpy confirmed that this adsorption process was exothermic. The instrumental analyses confirmed the adsorption of ammonium ion onto CSAC.

  2. Two di-alkyl-ammonium salts of 2-amino-4-nitro-benzoic acid: crystal structures and Hirshfeld surface analysis.

    PubMed

    Wardell, James L; Jotani, Mukesh M; Tiekink, Edward R T

    2016-12-01

    The crystal structures of two ammonium salts of 2-amino-4-nitro-benzoic acid are described, namely di-methyl-aza-nium 2-amino-4-nitro-benzoate, C2H8N(+)·C7H5N2O4(-), (I), and di-butyl-aza-nium 2-amino-4-nitro-benzoate, C8H20N(+)·C7H5N2O4(-), (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl-ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti-periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl-ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra-molecular chain by charge-assisted amine-N-H⋯O(carboxyl-ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N-O⋯π(arene) and methyl-C-H⋯O(nitro) inter-actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N-H⋯O(carboxyl-ate) hydrogen bonding. The formation of ammonium

  3. Selective Production of Electrostatically-Bound Adducts of Alkyl Cations/Polyoxoanions by the Collision-Induced Fragmentations of Their Quaternary Ammonium Counterparts

    NASA Astrophysics Data System (ADS)

    Cao, Jie; Xu, Chong; Fan, YanXuan; Fan, LinYuan; Zhang, XiuHui; Hu, ChangWen

    2013-06-01

    Solutions of the quaternary ammonium salts of a set of classic polyoxometalates (POMs) (Keggin [XM12O40]n-, Dawson [P2W18O62]6-, and Lindqvist [M6O19]2- (X = P, Si; M = W, Mo) were characterized by electrospray mass spectrometry. The gas-phase fragmentations of a series of quaternary ammonium-associated clusters were investigated by their collision-induced dissociations to elucidate their fragmentation mechanisms. It was found that the quaternary ammonium-associated clusters had distinctive dissociation characteristics. Moreover, the mono-quaternary ammonium-associated clusters, {NR4[POMs]}(n-1)-, shared a common fragmentation feature, that is, they decomposed exclusively into their respective alkyl cation-bound clusters irrespective of the different cation sizes and the different natures of the polyoxoanions. The optimized geometries and the binding energies of the mono cation-bound Lindqvist POM-based clusters were obtained by calculations. To the best of our knowledge, this is the first investigation of the gas-phase fragmentations of these noncovalent complexes between organic amines and inorganic POM anions by a combination of theory and mass spectrometry.

  4. Removal of ammonium and nitrate ions from mine effluents by membrane technology

    SciTech Connect

    Awadalla, F.T.; Striez, C.; Lamb, K. )

    1994-02-01

    Ammonium and nitrate ions could be removed from synthetic and actual mine effluents by using nanofiltration (NF) and reverse osmosis (RO) membranes. RO membranes were found more effective in removing these ions (>99% for NH[sub 4][sup +] and about 97% for NO[sup [minus

  5. Determination of ammonium in a buddingtonite sample by ion-chromatography

    USGS Publications Warehouse

    Klock, P.R.; Lamothe, P.J.

    1986-01-01

    An ion-chromatographic method for the direct determination of ammonium, potassium, and sodium in geologic materials is described. Samples are decomposed with a mixture of hydrofluoric and hydrochloric acids in a sealed polycarbonate bottle heated in a microwave oven. The ion-chromatograph separates the cations and determines them by conductivity measurement. The ammonium concentrations thus determined have been verified by use of an ammonia-specific electrode. A total of 32 analyses of ammonium salts by both techniques showed an average error of -4%, with a relative standard deviation (RSD) of 6%. The ammonium concentrations found in a buddingtonite sample had an RSD of 2.2% and their mean agreed with that obtained by the Kjeldahl method. By use of the prescribed dilution of the sample, detection limits of 0.1% can be achieved for all three cations. ?? 1986.

  6. Upgrading fertilizer production wastewater effluent quality for ammonium discharges through ion exchange with clinoptilolite.

    PubMed

    Beler-Baykal, B; Allar, A D

    2008-06-01

    It had previously been shown that ammonium selective natural zeolite clinoptilolite may be used successfully as an ion exchanger for ammonium removal and nitrogen control from domestic wastewater. The process had been reported to be acceptable either by itself alone or as an upgrade. In this work, the possibility of using clinoptilolite for ammonium removal from fertilizer production wastewater was investigated. The fertilizer plant under consideration was rather a non-typical one with a lower ammonium strength than what is normally expected, and a variable effluent concentration. Batch experiments were performed to assess the capacity of clinoptilolite towards ammonium removal from an industrial wastewater at two different pHs. Flow experiments for the characterization of system behavior under continuous feeding conditions at different contact times were conducted for breakthrough analysis. Both real and simulated fertilizer wastewater samples were investigated and the results have shown that the real one may successfully be represented by the simulated one. Experimental results have shown that surface capacities exceeding 14 mg ammonium g(-1) clinoptilolite could be attained, complete removal of ammonium may be achieved with empty bed contact times of 10 min or higher and ion exchange with clinoptilolite could be used successfully to comply with the effluent standards given for the fertilizer plant.

  7. Investigation of double bond conversion, mechanical properties, and antibacterial activity of dental resins with different alkyl chain length quaternary ammonium methacrylate monomers (QAM).

    PubMed

    He, Jingwei; Söderling, Eva; Vallittu, Pekka K; Lassila, Lippo V J

    2013-01-01

    In order to endow dental resin with antibacterial activity, a series of antibacterial quaternary ammonium methacrylate monomers (QAM) with different substituted alkyl chain length (from 10 to 18) were incorporated into commonly used 2,2-bis[4-(2'-hydroxy-3'-methacryloyloxy-propoxy)-phenyl]propane (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50 wt/50 wt) dental resin as immobilized antibacterial agents. Double bond conversion (DC), flexural strength (FS) and modulus (FM), and young and mature biofilms inhibition effectiveness of prepared dental resins were studied and Bis-GMA/TEGDMA without QAM was used as reference. Results showed that there was no significant difference on DC, FS, and FM between copolymer with and without 5 wt% QAM. Substituted alkyl chain length of QAM had no influence on DC, FS, and FM of copolymer, but had influence on antibacterial activity of copolymer. Antibacterial activity of copolymer increased with increasing of substituted alkyl chain length of QAM, and the sequence followed as 5%C10 < 5%C11 ≈ 5%C12 < 5%C16 ≈ 5%C18. Copolymers containing C18 and C16 had the best inhibition effectiveness on both young biofilm and mature biofilm, copolymers containing C12 and C11 only had inhibition effectiveness on young biofilm and copolymer containing C10 had none inhibition effectiveness on neither young biofilm nor mature biofilm.

  8. Phosphate-dependent glutaminase in enterocyte mitochondria and its regulation by ammonium and other ions.

    PubMed

    Masola, B; Zvinavashe, E

    2003-06-01

    The effects of ammonium and other ions on phosphate dependent glutaminase (PDG) activity in intact rat enterocyte mitochondria were investigated. Sulphate and bicarbonate activated the enzyme in absence and presence of added phosphate. In presence of 10 mM phosphate, ammonium at concentrations <1 mM inhibited the enzyme. This inhibition was reversed by increased concentration of phosphate or sulphate. The inhibition of PDG by ammonium in presence of 10 mM phosphate was biphasic with respect to glutamine concentration, its effect being through a lowering of V(max) at glutamine concentration of Ammonium and bicarbonate ions may therefore be important physiological regulators of PDG. It is suggested that phosphate and other polyvalent ions may function by preventing product inhibition of the enzyme through promotion of PDG dimer formation. The dimerized enzyme may have a high affinity for glutamine and reduced sensitivity to inhibition by ammonium ions.

  9. Improving Cellulose Dissolution in Ionic Liquids by Tuning the Size of the Ions: Impact of the Length of the Alkyl Chains in Tetraalkylammonium Carboxylate.

    PubMed

    Meng, Xiangqian; Devemy, Julien; Verney, Vincent; Gautier, Arnaud; Husson, Pascale; Andanson, Jean-Michel

    2017-01-30

    Twenty ionic liquids based on tetraalkylammonium cations and carboxylate anions have been synthesized, characterized, and tested for cellulose dissolution. The amount of cellulose dissolved in these ionic liquids depends strongly on the size of the ions: from 0 to 22 wt % cellulose can be dissolved at 90 °C. The best ionic liquids are less viscous and ammonium carboxylate based ionic liquids can dissolve as much as imidazolium-based ones. The viscosity of an ionic liquid can be decreased by the addition of DMSO as a cosolvent. After the addition of cosolvent, similar amounts of cellulose per ions are reached for most ionic liquids. As observed by rheology, ionic liquids with the longest alkyl chains form a gel when a high amount of cellulose is dissolved; this drastically limits their potential. Molecular simulations and IR spectroscopy have also been used with the aim of understanding how molecular interactions differ between efficient and inefficient ionic liquids.

  10. Liquid-liquid distribution of ion associates of tetrabromoindate(III) with quaternary ammonium counter ions.

    PubMed

    Yamamoto, K; Matsumoto, A

    1997-11-01

    The solvent extraction of an ion associate of tetrabromoindate(III) ion, InBr(-)(4), with quaternary ammonium cations (Q(+)) has been studied. The extraction constant (K(ex)) were determined for the ion associates of InBr(-)(4) with Q(+) between an aqueous phase and several organic phases (chloroform, chlorobenzene, benzene and toluene). A linear relationship was found between log K(ex) and the total number of carbon atoms in Q(+); from the slope of the lines, the contribution of a methylene group to log K(ex) was calculated to be 0.91 for the chloroform extraction system and 0.52 for the other extraction systems. The extractability with alkyltrimethylammonium cations was larger than that with symmetrical tetraalkylammonium cations and the mean difference in log K(ex) for two cations (one of each type) with the same number of carbon atoms was about 1.3. From the extraction constant obtained, the extractability of InBr(-)(4) among metal-halogeno complex anions was in the order TlBr(-)(4) > BiI(-)(4) > AuBr(-)(4) > AuCl(-)(4) > TlCl(-)(4) > InBr(-)(4) > CuCl(-)(2).

  11. Interplay between alkyl chain asymmetry and cholesterol addition in the rigid ion pair amphiphile bilayer systems

    NASA Astrophysics Data System (ADS)

    Huang, Fong-yin; Chiu, Chi-cheng

    2017-01-01

    Ion pair amphiphile (IPA), a molecular complex composed of a pair of cationic and anionic surfactants, has been proposed as a novel phospholipid substitute. Controlling the physical stability of IPA vesicles is important for its application developments such as cosmetic and drug deliveries. To investigate the effects of IPA alkyl chain combinations and the cholesterol additive on the structural and mechanical properties of IPA vesicular bilayers, we conducted a series of molecular dynamics studies on the hexadecyltrimethylammonium-dodecylsulfate (HTMA-DS) and dodecyltrimethylammonium-hexadecylsulfate (DTMA-HS) IPA bilayers with cholesterol. We found that both IPA bilayers are in the gel phase at 298 K, consistent with experimental observations. Compared with the HTMA-DS system, the DTMA-HS bilayer has more disordered alkyl chains in the hydrophobic region. When adding cholesterol, it induces alkyl chain ordering around its rigid sterol ring. Yet, cholesterol increases the molecular areas for all species and disturbs the molecular packing near the hydrophilic region and the bilayer core. Cholesterol also promotes the alkyl chain mismatch between the IPA moieties, especially for the DTMA-HS bilayer. The combined effects lead to non-monotonically enhancement of the membrane mechanical moduli for both IPA-cholesterol systems. Furthermore, cholesterol can form H-bonds with the alkylsulfate and thus enhance the contribution of alkylsulfate to the overall mechanical moduli. Combined results provide valuable molecular insights into the roles of each IPA component and the cholesterol on modulating the IPA bilayer properties.

  12. Identification of alkyl dimethylbenzylammonium surfactants in water samples by solid-phase extraction followed by ion trap LC/MS and LC/MS/MS

    USGS Publications Warehouse

    Ferrer, I.; Furlong, E.T.

    2001-01-01

    A novel methodology was developed for the determination of alkyl (C12, C14, and C16) dimethylbenzylammonium chloride (benzalkonium chloride or BAC, Chemical Abstract Service number: 8001-54-5) in water samples. This method is based on solid-phase extraction (SPE) using polymeric cartridges, followed by high-performance liquid chromatography/ion trap mass spectrometry (LC/MS) and tandem mass spectrometry(MS/MS) detection, equipped with an electrospray interface in positive ion mode. Chromatographic separation was achieved for three BAC homologues by using a C18 column and a gradient of acetonitrile/10 millimolar aqueous ammonium formate. Total method recoveries were higher than 71% in different water matrices. The main ions observed by LC/MS were at mass-to-charge ratios (m/z) of 304, 332, and 360, which correspond to the molecular ions of the C12, C14, and C16 alkyl BAC, respectively. The unequivocal structural identification of these compounds in water samples was performed by LC/MS/MS after isolation and subsequent fragmentation of each molecular ion. The main fragmentation observed for the three different homologues corresponded to the loss of the toluyl group in the chemical structure, which leads to the fragment ions at m/z 212, 240, and 268 and a tropylium ion, characteristic of all homologues, at m/z 91. Detection limits for the methodology developed in this work were in the low nanogram-per-liter range. Concentration levels of BAC - ranging from 1.2 to 36.6 micrograms per liter - were found in surface-water samples collected downstream from different wastewater-treatment discharges, thus indicating its input and persistence through the wastewater-treatment process.

  13. Identification of alkyl dimethylbenzylammonium surfactants in water samples by solid-phase extraction followed by ion trap LC/MS and LC/MS/MS.

    PubMed

    Ferrer, I; Furlong, E T

    2001-06-15

    A novel methodology was developed for the determination of alkyl (C12, C14, and C16) dimethylbenzylammonium chloride (benzalkonium chloride or BAC, Chemical Abstract Service number: 8001-54-5) in water samples. This method is based on solid-phase extraction (SPE) using polymeric cartridges, followed by high-performance liquid chromatography/ion trap mass spectrometry (LC/MS) and tandem mass spectrometry(MS/MS) detection, equipped with an electrospray interface in positive ion mode. Chromatographic separation was achieved for three BAC homologues by using a C18 column and a gradient of acetonitrile/10 millimolar aqueous ammonium formate. Total method recoveries were higher than 71% in different water matrices. The main ions observed by LC/MS were at mass-to-charge ratios (m/z) of 304, 332, and 360, which correspond to the molecular ions of the C12, C14, and C16 alkyl BAC, respectively. The unequivocal structural identification of these compounds in water samples was performed by LC/MS/MS after isolation and subsequent fragmentation of each molecular ion. The main fragmentation observed for the three different homologues corresponded to the loss of the toluyl group in the chemical structure, which leads to the fragment ions at m/z 212, 240, and 268 and a tropylium ion, characteristic of all homologues, at m/z 91. Detection limits for the methodology developed in this work were in the low nanogram-per-liter range. Concentration levels of BAC--ranging from 1.2 to 36.6 micrograms per liter--were found in surface-water samples collected downstream from different wastewater-treatment discharges, thus indicating its input and persistence through the wastewater-treatment process.

  14. Ammonium ion binding to DNA G-quadruplexes: do electrospray mass spectra faithfully reflect the solution-phase species?

    PubMed Central

    Balthasart, Françoise; Plavec, Janez; Gabelica, Valérie

    2013-01-01

    G-quadruplex nucleic acids can bind ammonium ions in solution and these complexes can be detected by electrospray mass spectrometry (ESI-MS). However, because ammonium ions are volatile, the extent to which ESI-MS quantitatively could provide an accurate reflection of such solution-phase equilibria is unclear. Here we studied five G-quadruplexes having known solution-phase structure and ammonium ion binding constants: the bimolecular G-quadruplexes (dG4T4G4)2, (dG4T3G4)2 and (dG3T4G4)2, and the intramolecular G-quadruplexes dG4(T4G4)3 and dG2T2G2TGTG2T2G2 (thrombin binding aptamer). We found that not all mass spectrometers are equally suited to reflect the solution phase species. Ion activation can occur in the electrospray source, or in a high-pressure travelling wave ion mobility cell. When the softest instrumental conditions are used, ammonium ions bound between G-quartets, but also additional ammonium ions bound at specific sites outside the external G-quartets can be observed. However, even specifically bound ammonium ions are in some instances too labile to be fully retained in the gas phase structures, and although the ammonium ion distribution observed by ESI-MS shows biases at specific stoichiometries, the relative abundances in solution are not always faithfully reflected. Ion mobility spectrometry results show that all inter-quartet ammonium ions are necessary to preserve the G-quadruplex fold in the gas phase. Ion mobility experiments therefore help assigning the number of inner ammonium ions in the solution phase structure. PMID:23132414

  15. Alanine synthesis from glyceraldehyde and ammonium ion in aqueous solution

    NASA Technical Reports Server (NTRS)

    Weber, A. L.

    1985-01-01

    The formation of alanine (ala) form C(14)-glyceraldehyde and ammonium phosphate in the presence or absence of a thiol is reported. At ambient temperature, ala synthesis was six times more rapid in the presence of 3-mercaptopropionic acid than in its absence (0.6 and 0.1 percent, respectively, after 60 days). Similarly, the presence of another thiol, N-acetylcysteinate, increased the production of ala, as well as of lactate. The reaction pathway of thiol-catalyzed synthesis of ala, with the lactic acid formed in a bypath, is suggested. In this, dehydration of glyceraldehyde is followed by the formation of hemithioacetal. In the presence of ammonia, an imine is formed, which eventually yields ala. This pathway is consistent with the observation that the rate ratio of ala/lactate remains constant throughout the process. The fact that the reaction takes place under anaerobic conditions in the presence of H2O and with the low concentrations of simple substrates and catalysts makes it an attractive model prebiotic reaction in the process of molecular evolution.

  16. EPR and optical absorption studies on Gd 3+ ions in ammonium hydrogen malonate single crystals

    NASA Astrophysics Data System (ADS)

    Kripal, Ram; Mishra, Indrajeet

    2010-01-01

    X-Band electron paramagnetic resonance (EPR) studies of Gd 3+ ions in ammonium hydrogen malonate single crystals have been done at room temperature. Detailed EPR analysis indicates the presence of four physically equivalent but magnetically inequivalent sites. The zero-field splitting parameters and g factor are determined. The Gd 3+ ion is in 8S state; its levels are split by the action of the crystalline electric field of monoclinic symmetry. The optical absorption spectra of Gd 3+ ions in single crystals of ammonium hydrogen malonate are also recorded at room temperature. The energy levels of the 4f 7 configuration are calculated and compared with those observed experimentally. The values of E1=5854±11, E2=31±0.36, E3=592±3.3 and ζ 4f=1595±25 cm -1 are found to give the best over-all agreement between experimentally observed and calculated levels.

  17. Alkyl Pyrocarbonate Electrolyte Additives for Performance Enhancement of Li Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Surampudi, S.

    2000-01-01

    Lithium ion rechargeable batteries are being developed for various aerospace applications under a NASA-DoD Interagency program. These applications require further improvements in several areas, specifically in the cycle life for LEO and GEO satellites and in the low temperature performance for the Mars Lander and Rover missions. Accordingly, we have been pursuing research studies to achieve improvement in the low temperature performance, long cycle life and active life of Li ion cells. The studies are mainly focused on electrolytes, to identify newer formulations of new electrolyte additives to enhance Li permeability (at low temperatures) and stability towards the electrode. The latter approach is particularly aimed at the formation suitable SEI (solid electrolyte interphase) on carbon electrodes. In this paper, we report the beneficial effect of using alkyl pyrocarbonates as electrolyte additives to improve the low temperature performance of Li ion cells.

  18. Ion exchange of ammonium in natural and synthesized zeolites.

    PubMed

    Wang, Yifei; Lin, Feng; Pang, Wenqin

    2008-12-30

    In this study, zeolite Na-P and Na-Y was prepared by hydrothermal treatment of the Chinese natural clinoptilolite with NaOH. The ion exchange of NH4+ into the three zeolites in the temperature range of 288-333K was also investigated, and the thermodynamic parameters were calculated. The selectivity sequence for NH4+ entering the sodium form of the three materials was Na-clinoptilolite>Na-Y>Na-P, as indicated by values of DeltaG degrees . The results demonstrated that the Si/Al molar ratio of zeolites determined the selectivity for NH4+.

  19. A Stable Fluorinated and Alkylated Lithium Malonatoborate Salt for Lithium Ion Battery Application

    SciTech Connect

    Wan, Shun; Jiang, Xueguang; Guo, Bingkun; Dai, Sheng; Goodenough, John B.; Sun, Xiao-Guang

    2015-01-01

    A new fluorinated and alkylated lithium malonatoborate salt, lithium bis(2-methyl-2-fluoromalonato)borate (LiBMFMB), has been synthesized for lithium ion battery application. A 0.8 M LiBMFMB solution is obtained in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (1:2 by wt.). The new LiBMFMB based electrolyte exhibits good cycling stability and rate capability in LiNi0.5Mn1.5O4 and graphite based half-cells.

  20. Stepwise determination of quaternary ammonium salts and aromatic amines in pharmaceuticals by ion association titration.

    PubMed

    Sakai, T

    2001-12-01

    A stepwise titrimetric method has been developed for the simultaneous determination of pharmaceutical quaternary ammonium salts (R4N+) and aromatic amines (R3N). The method is based on the solvent extraction of R4N+ and R3NH+ with an ion association reagent. Sodium tetrakis(4-fluorophenyl)borate and sodium tetraphenylborate were used as titrants and potassium tetrabromophenolphthalein ethyl ester (TBPE) was used as an indicator. The ion associate which formed between R4N+ ion and TBPE made a blue color in 1,2-dichloroethane, while the ion associate formed between R3NH+ and TBPE showed a red-violet one. Sample solutions containing quaternary ammonium and/or amine compounds were titrated with sodium tetrakis(4-fluorophenyl)borate or sodium tetraphenylborate. When one drop of excess titrant was added, the color of the organic phase turned from blue or red-violet to yellow at the equivalence point. On the other hand, in the mixture of R4N+ and R3N, the color changed from blue to red-violet at the first equivalence point, and then its color turned to yellow at the second equivalence point. The quaternary ammonium compound and aromatic amine in pharmaceuticals could be simultaneously and successfully determined by the proposed titration method.

  1. Electrophoretic Mobility Study of the Adsorption of Alkyl Xanthate Ions on Galena and Sphalerite.

    PubMed

    Song, S.; Lopez-Valdivieso, A.; Ojeda-Escamilla, M. C.

    2001-05-01

    The adsorption of ethyl and amyl xanthate ions on galena and sphalerite fines has been studied using electrophoretic light-scattering (ELS) measurements. It was performed on galena and sphalerite (<2&mgr;m) in aqueous solution at different potassium ethyl xanthate (PEX) and potassium amyl xanthate (PAX) concentrations. It has been observed that the presence of PEX or PAX caused the isoelectric points (IEP) of galena and sphalerite fines to shift and the electrophoretic mobility to reverse in sign, indicating that the xanthate ions chemisorbed on galena and sphalerite surfaces. This adsorption markedly broadened the electrophoretic mobility distribution of the mineral fines, suggesting that the populations of the particles have quite different adsorption densities of xanthate ions, and therefore the particle hydrophobicity was different. This phenomenon might be attributable to the effect of the hemimicelle adsorption of the xanthate ions on the minerals, the nonuniform distribution of active sites and their degree of activity, the effect of particle size and shape, etc. The nonuniform adsorption has been found to increase with increasing PEX or PAX concentration, reaching a maximum at a medium concentration followed by a decline. Also, experimental results have demonstrated that the nonuniform adsorption of the xanthate ions is much stronger on sphalerite than on galena, which may explain why sphalerite has a worse flotation response than galena when alkyl xanthates are used as collectors in flotation systems. Copyright 2001 Academic Press.

  2. Simultaneous uptake of ammonium and phosphate ions by compounds prepared from paper sludge ash.

    PubMed

    Okada, Kiyoshi; Ono, Yosuke; Kameshima, Yoshikazu; Nakajima, Akira; MacKenzie, Kenneth J D

    2007-03-22

    Al-containing CaO-SiO(2)-H(2)O phases were prepared by hydrothermal treatment of mixtures of paper sludge ash (PSA) with various silica and calcia sources and their properties were determined with particular reference to the simultaneous uptake of ammonium and phosphate ions, which are implicated in the eutrophication of lakes and ponds. After examination of various silica and calcia sources, Ca(OH)(2) and SiO(2) sol were selected as the most appropriate starting materials. Dry milling was found to be superior to wet milling in avoiding contamination from the milling media during mixing. Nine samples with three different Ca/Si ratios and Al(2)O(3) contents were prepared with various mass ratios of Ca(OH)(2), PSA and SiO(2). The chemical compositions of the hydrothermal products of these mixtures moved towards the tieline of CaSiO(3)-PSA, with respect to the starting compositions. The major phase formed in all samples was poorly crystalline C-S-H(I), with hydroxysodalite also formed in the Al-containing mixtures. All the products showed a capacity for the simultaneous uptake of ammonium and phosphate ions. The saturated sorption capacities calculated from the Langmuir equation ranged from 0.9 to 2.4mmol/g for the ammonium ion and from 3.3 to 5.2mmol/g for the phosphate ion. Since the sorption capacities for both ions increased with increasing Ca contents of the product, substitution of Ca(2+) for NH(4)(+) and the formation of calcium phosphate phases such as apatite and brushite by precipitation are thought to be the main sorption mechanisms.

  3. Molecular determinants for binding of ammonium ion in the ammonia transporter AmtB-A quantum chemical analysis.

    PubMed

    Liu, Yuemin; Hu, Xiche

    2006-02-02

    The transport of ammonium across the cell membrane represents an important biological process in all living organisms. The mechanisms for ammonium translocation were analyzed by computer simulations based on first principles. Intermolecular interaction energies between the differentially methylated ammonium and the ammonium channel protein AmtB were calculated by means of the supermolecular approach at the MP2/6-311+G* level based on the high-resolution crystal structures of ligand-bound protein complexes. Our analysis attributes the molecular determinants for protein-ligand recognition in ammonium transporter AmtB to the aromatic cage formed by three aromatic residues Phe103, Phe107, and Trp148, as well as Ser219. The former residues are involved in cation-pi interactions with the positively charged methylated ammoniums. The latter residue acts as a hydrogen bond acceptor to ammonium. Thus, this work provides directly the missing evidence for the hypothesized role played by the wider vestibule site of AmtB at the periplasmic side of the membrane in "recruiting" NH(4)(+) or methylammonium ions as proposed by Khademi et al. (Science 2004, 305, 1587). In addition, a hybrid quantum mechanics/molecular mechanics scheme was applied to optimize the structures of differentially methylated ammoniums in the AmtB protein, which generated structural and energetic data that provide a satisfactory explanation to the experimental observation that tetramethylammonium is not inhibitory to conducting ammonium and methylammonium in the ammonium transport channel.

  4. DFT-D study of 14N nuclear quadrupolar interactions in tetra-n-alkyl ammonium halide crystals.

    PubMed

    Dib, Eddy; Alonso, Bruno; Mineva, Tzonka

    2014-05-15

    The density functional theory-based method with periodic boundary conditions and addition of a pair-wised empirical correction for the London dispersion energy (DFT-D) was used to study the NMR quadrupolar interaction (coupling constant CQ and asymmetry parameter ηQ) of (14)N nuclei in a homologous series of tetra-n-alkylammonium halides (C(x)H(2x+1))4N(+)X(-) (x = 1-4), (X = Br, I). These (14)N quadrupolar properties are particularly challenging for the DFT-D computations because of their very high sensitivity to tiny geometrical changes, being negligible for other spectral property calculations as, for example, NMR (14)N chemical shift. In addition, the polarization effect of the halide anions in the considered crystal mesophases combines with interactions of van der Waals type between cations and anions. Comparing experimental and theoretical results, the performance of PBE-D functional is preferred over that of B3LYP-D. The results demonstrated a good transferability of the empirical parameters in the London dispersion formula for crystals with two or more carbons per alkyl group in the cations, whereas the empirical corrections in the tetramethylammonium halides appeared to be inappropriate for the quadrupolar interaction calculation. This is attributed to the enhanced cation-anion attraction, which causes a strong polarization at the nitrogen site. Our results demonstrated that the (14)N CQ and ηQ are predominantly affected by the molecular structures of the cations, adapted to the symmetry of the anion arrangements. The long-range polarization effect of the surrounding anions at the target nitrogen site becomes more important for cells with lower spatial symmetry.

  5. Uranyl complexes of alkyl-bridged ditopic diaminotetraphenol ligands and their use as uranyl ion extractors.

    PubMed

    Riisiö, Antti; Väisänen, Ari; Sillanpää, Reijo

    2013-08-05

    The coordination chemistry of uranyl ions was studied using long n-alkyl chain (n = 5-8) bridged by N,N,N',N'-tetrakis(2-hydroxy-3-methyl-5-tert-butylbenzyl)diaminoalkanes (H4L1-H4L4) as ligands. All ligands formed 2:1 (U-to-L ratio) complexes with uranyl ions, but in addition 1:1 complexes could be characterized using ligands H4L2 and H4L3. The complexes were characterized by elemental analysis, spectroscopy (IR and NMR), and X-ray diffraction. The 2:1 complexes are of two types: [(UO2)2(H2Lm)(NO3)2(solvent)2] (m = 1 and 2; solvent = ethanol or propanol) or (cation)2[(UO2)2(H2Lm)(NO3)2(anion)2]·xsolvent (m = 2 and 4; cation = triethylammonium, anion = nitrate or thiocyanate, and solvent = dichloromethane and acetonitrile; x = 1 or 2). The 1:1 complexes have the formula [(UO2)2(H2Lm)2] (m = 2 and 3). In the solid state, 2:1 complexes are almost in a linear conformation with the uranyl ion at both ends of the ligand. The 1:1 complexes are cyclic dinuclear molecules. Preliminary studies of the ligands as uranyl ion extractors from water to dichloromethane were also performed. A high extraction efficiency was observed with H4L3 for uranyl ions, and in the presence of Cu(II), Ni(II), Co(II), and Zn(II) ions, a good extraction selectivity for uranyl ions was found with H4L1.

  6. The effect of ammonium ions on oxygen reduction and hydrogen peroxide formation on polycrystalline Pt electrodes

    NASA Astrophysics Data System (ADS)

    Halseid, Rune; Heinen, Martin; Jusys, Zenonas; Jürgen Behm, R.

    The influence of ammonium ions on the activity and selectivity of the electrocatalytic oxygen reduction reaction (ORR) on polycrystalline Pt was investigated in model studies under continuous mass transport, both in sulfuric and perchloric acid solutions. Ammonium was found to increase the yield of hydrogen peroxide, particularly in sulfuric acid, but also in perchloric acid solutions, and also at higher potentials (0.80-0.90 V RHE) typical for fuel cell cathode operation, which may severely impair the long-term stability of membranes and electrodes in fuel cells exposed to fuel gases and/or air containing ammonia. Adsorbed species, assigned to ammonia and nitric oxide, were identified on a Pt film electrode using in situ FTIR spectroscopy. Adsorbed nitric oxide could only be observed in perchloric acid solutions. The higher coverage of adsorbed ammonia in sulfuric acid solution is attributed to a stabilization by coadsorbed (bi-)sulfate species; the higher total coverage in this electrolyte can explain the larger effect of ammonium ions on the ORR activity and selectivity in sulfuric compared to perchloric acid solution.

  7. The application of membrane filtration for the removal of ammonium ions from potable water.

    PubMed

    Kurama, H; Poetzschke, J; Haseneder, R

    2002-06-01

    It is well recognized that soluble ammonia and nitrite in drinking water has chronic effects on humans. Ammonia has potential environmental health hazards, particularly to young children. European Union Standards limit the concentration of ammonia to 0.5 mg/l in drinking water. In Eskisehir (Turkey) drinking and tap water are supplied from a water treatment plant, consisting mainly of screening, sedimentation, filtration and sterilization units and having a capacity of 80.000 m3/d. Depend on the industrial and climatic effects the observed high ammonium concentration in treated water causes undesirable effects of water quality. Therefore, people in Eskisehir do not want to use tap water for drinking. The aim of the study was to evaluate the performance of membrane processes, i.e. Nanofiltration and reverse osmosis to the removal of ammonium and Ca ions from plant effluent and recommend one of them for a subsequent pilot plant application.

  8. Metal ion hydrocarbon bidentate bonding in alkyl acetates, methyl alkanoates, alcohols and 1-alkenes: a comparative study.

    PubMed

    Burgers, Peter C; Holmes, John L; Terlouwc, Johan K

    2016-01-01

    The relative affinity of the monovalent metal ions Li(+), Na(+), Cu(+) and Ag(+) towards a series of aliphatic alkyl acetates and some selected 1-alkenes (P) was examined using the kinetic method. A detailed analysis of the dissociation characteristics of a series of mixed metal-bound dimer ions of the type P1-M(+)-P2 and the evaluated proton affinities (PAs) of the monomers shows that the affinity of the cation towards long-chain alkyl acetates and alkenes (having a chain length ≤ C4) is markedly enhanced. In line with recent studies of nitriles, alcohols and methyl alkanoates, this is attributed to a bidentate interaction of the metal ion with the functional group or double bond and the aliphatic chain. In particular, the longer chain alkyl acetates, methyl alkanoates and alcohols show a remarkably similar behaviour with respect to silver ion hydrocarbon bonding. The Ag(+) adducts of the alkyl acetates dissociate by loss of CH3COOH. This reaction becomes more pronounced at longer chain lengths, which points to metal ion bidentate formation in [Ag(+)···1-alkene] product ions having a long hydrocarbon chain. In the same vein, the heterodimers [1- hexene···Ag(+)···1-heptene] and [1- heptene···Ag(+)···1-octene] dissociate primarily into [Ag(+)···1-heptene] and [Ag(+)···1-octene] ions, respectively. Hydrocarbon bidentate formation in [Ag(+)···1-octene] also reveals itself by the reluctance of this ion to react with water in an ion trap, as opposed to [Ag(+)···1-hexene] which readily undergoes hydration.

  9. Chromatographic separation of certain metal ions using a bifunctional quaternary ammonium-sulfonate mixed bed ion-exchanger.

    PubMed

    Lasheen, Y F; Seliman, A F; Abdel-Rassoul, A A

    2006-12-15

    The separation behaviour of Pb(2+), Cu(2+), Cd(2+), Co(2+), Zn(2+) and Ni(2+) on bifunctional quaternary ammonium-sulfonate mixed ion-exchangers (Dionex, IonPac CS5 and CG5) was studied using different eluents including solutions of oxalic acid, potassium oxalate, sodium oxalate and ammonium oxalate. Separated metal ions were followed by using 4-(2-pyridylazo) resorcinol (PAR) as post-colouring complex. The retention factors of different ions proved to be dependent on the pH, concentration, nature of each complexing agent, and to less extent on eluent flow rate. The retention behaviour and separation mechanism of complexed metal analytes are discussed in the light of the stability of metal complexes and the ligand complexing ability of used eluent. Comparison between various mobile phases is evaluated, and both sodium and potassium oxalate can be used successfully for simultaneous separation of studied metals with good resolution within short elution periods. The method can be used in different applications including analysis of bottled water from different resources.

  10. EnFET for urea determination in biological fluids using ammonium ion detection

    NASA Astrophysics Data System (ADS)

    Dawgul, Marek; Trybun, Tomasz; Pijanowska, Dorota G.; Torbicz, Wladyslaw

    2003-09-01

    In this paper a method of urease immobilization on the surface of the Siloprene membrane of the ammonium ion sensitive ChemFET is presented. The usability of the sensor for determination of urea in solutions at pH typical for biological fluids (pH 6 to pH 7.5) has been investigated. Due to the fact that the sensor exhibits high sensitivity to samples of low buffer capacity, the method of preliminary sample treatment, consisting in addition of buffers at adequate buffer capacity was developed. The sensors were tested in dialysate and blood plasma.

  11. Ion transport and structural dynamics in homologous ammonium and phosphonium-based room temperature ionic liquids

    DOE PAGES

    Griffin, Phillip J.; Holt, Adam P.; Tsunashima, Katsuhiko; ...

    2015-02-01

    Charge transport and structural dynamics in a homologous pair of ammonium and phosphonium based room temperature ionic liquids (ILs) have been characterized over a wide temperature range using broadband dielectric spectroscopy and quasi-elastic light scattering spectroscopy. We have found that the ionic conductivity of the phosphonium based IL is significantly enhanced relative to the ammonium homolog, and this increase is primarily a result of a lower glass transition temperature and higher ion mobility. Additionally, these ILs exhibit pronounced secondary relaxations which are strongly influenced by the atomic identity of the cation charge center. While the secondary relaxation in the phosphoniummore » IL has the expected Arrhenius temperature dependence characteristic of local beta relaxations, the corresponding relaxation process in the ammonium IL was found to exhibit a mildly non-Arrhenius temperature dependence in the measured temperature range-indicative of molecular cooperativity. These differences in both local and long-range molecular dynamics are a direct reflection of the subtly different inter-ionic interactions and mesoscale structures found in these homologous ILs.« less

  12. Ion transport and structural dynamics in homologous ammonium and phosphonium-based room temperature ionic liquids

    SciTech Connect

    Griffin, Phillip J.; Holt, Adam P.; Tsunashima, Katsuhiko; Sangoro, Joshua R.; Kremer, Friedrich; Sokolov, Alexei P.

    2015-02-01

    Charge transport and structural dynamics in a homologous pair of ammonium and phosphonium based room temperature ionic liquids (ILs) have been characterized over a wide temperature range using broadband dielectric spectroscopy and quasi-elastic light scattering spectroscopy. We have found that the ionic conductivity of the phosphonium based IL is significantly enhanced relative to the ammonium homolog, and this increase is primarily a result of a lower glass transition temperature and higher ion mobility. Additionally, these ILs exhibit pronounced secondary relaxations which are strongly influenced by the atomic identity of the cation charge center. While the secondary relaxation in the phosphonium IL has the expected Arrhenius temperature dependence characteristic of local beta relaxations, the corresponding relaxation process in the ammonium IL was found to exhibit a mildly non-Arrhenius temperature dependence in the measured temperature range-indicative of molecular cooperativity. These differences in both local and long-range molecular dynamics are a direct reflection of the subtly different inter-ionic interactions and mesoscale structures found in these homologous ILs.

  13. Ion transport and structural dynamics in homologous ammonium and phosphonium-based room temperature ionic liquids

    SciTech Connect

    Griffin, Philip J.; Holt, Adam P.; Tsunashima, Katsuhiko; Sangoro, Joshua R.; Kremer, Friedrich; Sokolov, Alexei P.

    2015-02-28

    Charge transport and structural dynamics in a homologous pair of ammonium and phosphonium based room temperature ionic liquids (ILs) have been characterized over a wide temperature range using broadband dielectric spectroscopy and quasi-elastic light scattering spectroscopy. We have found that the ionic conductivity of the phosphonium based IL is significantly enhanced relative to the ammonium homolog, and this increase is primarily a result of a lower glass transition temperature and higher ion mobility. Additionally, these ILs exhibit pronounced secondary relaxations which are strongly influenced by the atomic identity of the cation charge center. While the secondary relaxation in the phosphonium IL has the expected Arrhenius temperature dependence characteristic of local beta relaxations, the corresponding relaxation process in the ammonium IL was found to exhibit a mildly non-Arrhenius temperature dependence in the measured temperature range—indicative of molecular cooperativity. These differences in both local and long-range molecular dynamics are a direct reflection of the subtly different inter-ionic interactions and mesoscale structures found in these homologous ILs.

  14. Formation of nitrate and ammonium ions in titanium dioxide mediated photocatalytic degradation of organic compounds containing nitrogen atoms

    SciTech Connect

    Low, G.K.-C.; McEvoy, S.R.; Matthews, R.W. )

    1991-03-01

    The photocatalytic oxidation of a related series of primary, secondary, and tertiary amines and other nitrogen- and sulfur-containing organic compounds over a UV-illuminated film of TiO{sub 2} has been studied. The compounds were as follows: n-pentylamine, piperidine, pyridine, phenylalanine, desipramine, thioridazine, penicillamine, isosorbide dinitrate, 4-nitrocatechol, 2,4-dinitrophenol, cyclophosphamide, 5-fluorouracil, atrazine, ethylenediaminetetracetic acid, and tetrabutylammonium phosphate. Both ammonium and nitrate ions were formed. The relative concentration of the two ions depended on the nature of the nitrogen in a compound, but was also influenced by the illumination time and concentration of the solute. It was found that for n-pentylamine, piperidine and pyridine, the rate of formation of ammonium ions was n-pentylamine {much gt} pyridine > piperidine. The order of rates of nitrate formation was pyridine = piperidine {much gt} pentylamine. For n-pentylamine the rate of formation of ammonium ions was {approximately}100 times that of nitrate.

  15. CHLORIDEDETERMINATION IN HIGH IONIC STRENGTH SOLUTION OF AMMONIUM ACETATE USING NEGATIVE ION ELECTRON SPRAY IONIZATION (HPLC/MS)

    EPA Science Inventory

    A precise ion chromatography method has been developed for the determination of chloride in high ionic strength ammonium acetate solutions (10-5 M-5 M) using sodium carbonate/sodium bicarbonate as eluent. Negative ion electrospray ionization (ESI) mass spectrometry was used for q...

  16. Determination of alkyl amines in atmospheric aerosol particles: a comparison of gas chromatography-mass spectrometry and ion chromatography approaches

    NASA Astrophysics Data System (ADS)

    Huang, R.-J.; Li, W.-B.; Wang, Y.-R.; Wang, Q. Y.; Ho, K.-F.; Cao, J. J.; Wang, G. H.; Chen, X.; Haddad, I. EI; Zhuang, Z. X.; Wang, X. R.; Prévôt, A. S. H.; O'Dowd, C. D.; Hoffmann, T.

    2014-03-01

    In recent years low molecular weight alkyl amines have been recognized to play an important role in particle formation and growth in the lower atmosphere. However, major uncertainties are associated with their atmospheric processes, sources and sinks, mostly due to the lack of ambient measurements and the difficulties in accurate quantification of alkyl amines at trace level. In this study, we present the evaluation and optimization of two analytical approaches, i.e., gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC), for the determination of alkyl amines in aerosol particles. Alkyl amines were converted to carbamates through derivatization with isobutyl chloroformate for GC-MS determination. A set of parameters affecting the analytical performances of the GC-MS approach, including reagent amount, reaction time and pH value, was evaluated and optimized. The accuracy is 84.3-99.1%, and the limits of detection obtained are 1.8-3.9 pg. For the IC approach, a solid phase extraction (SPE) column was used to separate alkyl amines from interfering cations before IC analysis. 1-2% (v/v) of acetone (or 2-4% (v/v) of acetonitrile) was added to the eluent to improve the separation of alkyl amines on the IC column. The limits of detection obtained are 2.1-15.9 ng and the accuracy is 55.1-103.4%. The lower accuracy can be attributed to evaporation losses of amines during the sample concentration procedure. Measurements of ambient aerosol particle samples collected in Hong Kong show that the GC-MS approach is superior to the IC approach for the quantification of primary and secondary alkyl amines due to its lower detection limits and higher accuracy.

  17. Mixed ternary ion associate formation between xanthene dye, cinchona-alkaloid and quaternary ammonium ion and its application to the determination of trace amounts of quaternary ammonium salts in pharmaceuticals.

    PubMed

    Sakai, Tadao; Hirose, Akihiko

    2003-01-02

    Xanthene dyes such as eosin and tetraiodofluorescein form 1:2 ion associates with quaternary ammonium ions at pH 7-9; however, the development of color in the organic solvent is poor. When a quaternary ammonium salt is added in the extractable 1:2 associate formed between a xanthene dye and a cinchona-alkaloid in the neutral media, a mixed ternary ion associate (xanthene dye:cinchona-alkaloid:quaternary ammonium ion=1:1:1) is formed. Its extractability is enhanced due to the more bulky associate formation. The ion association caused by addition of cinchona-alkaloids is unique. Of the cinchona-alkaloids, quinidine and cinchonidine with tetraiodofluorescein show excellent effects on sensitivity and extractability. Eosin and tetraiodofluorescein are useful as ion association reagents in the ion associate formation. The apparent molar absorptivities are about 1x10(5) l mol(-1) cm(-1) and the calibration range for quaternary ammonium salt is from 2.5x10(-7) to 1.5x10(-6) M. The proposed method is applicable to the selective and sensitive determination of cetylpyridinium chloride, berberine chloride and benzethonium chloride in pharmaceuticals.

  18. Transition metal ion-assisted photochemical generation of alkyl halides and hydrocarbons from carboxylic acids

    SciTech Connect

    Carraher, Jack; Pestovsky, Oleg; Bakac, Andreja

    2012-03-14

    Near-UV photolysis of aqueous solutions of propionic acid and aqueous Fe3+ in the absence of oxygen generates a mixture of hydrocarbons (ethane, ethylene and butane), carbon dioxide, and Fe2+. The reaction becomes mildly catalytic (about five turnovers) in the presence of oxygen which converts a portion of alkyl radicals to oxidizing intermediates that reoxidize Fe2+. The photochemistry in the presence of halide ions (X− = Cl−, Br−) generates ethyl halides via halogen atom abstraction from FeXn3−n by ethyl radicals. Near-quantitative yields of C2H5X are obtained at ≥0.05 M X−. Competition experiments with Co(NH3)5Br2+ provided kinetic data for the reaction of ethyl radicals with FeCl2+ (k = (4.0 ± 0.5) × 106 M−1 s−1) and with FeBr2+ (k = (3.0 ± 0.5) × 107 M−1 s−1). Photochemical decarboxylation of propionic acid in the presence of Cu2+ generates ethylene and Cu+. Longer-chain acids also yield alpha olefins as exclusive products. These reactions become catalytic under constant purge with oxygen which plays a dual role. It reoxidizes Cu+ to Cu2+, and removes gaseous olefins to prevent accumulation of Cu+(olefin) complexes and depletion of Cu2+. The results underscore the profound effect that the choice of metal ions, the medium, and reaction conditions exert on the photochemistry of carboxylic acids.

  19. Tandem mass spectrometric analysis of novel diquaternary ammonium gemini surfactants and their bromide adducts in electrospray-positive ion mode ionization.

    PubMed

    Buse, Joshua; Badea, Ildiko; Verrall, Ronald E; El-Aneed, Anas

    2011-10-01

    Gemini surfactants are cationic lipids which are utilized for both in vitro and in vivo gene delivery. Structurally, they are comprised of two hydrophobic tail regions with polar head termini that are attached to one another through a spacer region. Structural elucidation and characterization of 29 novel diquaternary ammonium gemini surfactant molecules were achieved using a quadrupole time-of-flight mass spectrometer (QqToF-MS) and a quadrupole-hexapole-quadrupole mass spectrometer (QhQ-MS). The tested compounds were categorized into four distinct structural families based upon the composition of the spacer region. Single stage (MS), tandem stage (MS/MS) and quasimulti-stage (quasi MS(3)) mass spectrometric analysis allowed for confirmation of each gemini surfactant's molecular composition and structure through the identification of common and unique product ions. Identification of similarities in the gemini surfactants' fragmentation behaviour resulted in the production of a universal fragmentation pathway that can assist in the future MS/MS analysis of novel quaternary ammonium gemini surfactants, with unique product ions being indicative of specific structural elements. Furthermore, evidence for the association of agemini surfactant with bromine counter ion was confirmed during MS analysis of tested gemini surfactants regardless of their chemical composition; previously, evidence for bromine and gemini surfactant association was only observed with compounds bearing short alkyl spacer regions. MS/MS analysis of the bromine adducts was also confirmatory to the molecular structure.Understanding the ionization and fragmentation behaviour of gemini surfactants, including bromine adducts, will allow for future qualitative and quantitative identification of these novel drug delivery agents within biological samples.

  20. New Developments in Chiral Cooperative Ion Pairing Organocatalysis by Means of Ammonium Oxyanions and Fluorides: From Protonation to Deprotonation Reactions.

    PubMed

    Legros, Fabien; Oudeyer, Sylvain; Levacher, Vincent

    2016-10-13

    This personal account summarizes our contribution to the ion pairing organocatalysis mainly by use of chiral quaternary or tertiary ammonium fluorides, aryloxides and carboxylates. Starting from an experimental observation, we were able to develop several approaches for the enantioselective protonation of silyl enolates and enol esters giving rise to chiral carbonyl compounds bearing a stereogenic center at the α-position. Moving from protonation to deprotonation reactions, chiral ammonium ion pair catalysts were successfully applied to several asymmetric transformations such as an Henry reaction or a direct vinylogous aldol reaction to cite a few. An outlook of further possible developments in this field of research will also be discussed.

  1. Enantioselective Cyclopropanation with α-Alkyl-α-diazoesters Catalyzed by Chiral Oxazaborolidinium Ion: Total Synthesis of (+)-Hamavellone B.

    PubMed

    Shim, Su Yong; Kim, Jae Yeon; Nam, Miso; Hwang, Geum-Sook; Ryu, Do Hyun

    2016-01-15

    Chiral oxazaborolidinium ion-catalyzed asymmetric cyclopropanation of α- or α,β-substituted acroleins with α-alkyl-α-diazoesters has been developed. With this methodology, chiral functionalized cyclopropanes containing a quaternary stereogenic center were obtained with high to excellent enantioselectivities (up to >99% ee). The synthetic utility of optically enriched functionalized cyclopropane was demonstrated in the first total synthesis of (+)-hamavellone B, which establishes the absolute configuration of natural (+)-hamavellone B.

  2. To Break or to Brake Neuronal Network Accelerated by Ammonium Ions?

    PubMed Central

    Dynnik, Vladimir V.; Kononov, Alexey V.; Sergeev, Alexander I.; Teplov, Iliya Y.; Tankanag, Arina V.; Zinchenko, Valery P.

    2015-01-01

    Purpose The aim of present study was to investigate the effects of ammonium ions on in vitro neuronal network activity and to search alternative methods of acute ammonia neurotoxicity prevention. Methods Rat hippocampal neuronal and astrocytes co-cultures in vitro, fluorescent microscopy and perforated patch clamp were used to monitor the changes in intracellular Ca2+- and membrane potential produced by ammonium ions and various modulators in the cells implicated in neural networks. Results Low concentrations of NH4Cl (0.1–4 mM) produce short temporal effects on network activity. Application of 5–8 mM NH4Cl: invariably transforms diverse network firing regimen to identical burst patterns, characterized by substantial neuronal membrane depolarization at plateau phase of potential and high-amplitude Ca2+-oscillations; raises frequency and average for period of oscillations Ca2+-level in all cells implicated in network; results in the appearance of group of «run out» cells with high intracellular Ca2+ and steadily diminished amplitudes of oscillations; increases astrocyte Ca2+-signalling, characterized by the appearance of groups of cells with increased intracellular Ca2+-level and/or chaotic Ca2+-oscillations. Accelerated network activity may be suppressed by the blockade of NMDA or AMPA/kainate-receptors or by overactivation of AMPA/kainite-receptors. Ammonia still activate neuronal firing in the presence of GABA(A) receptors antagonist bicuculline, indicating that «disinhibition phenomenon» is not implicated in the mechanisms of networks acceleration. Network activity may also be slowed down by glycine, agonists of metabotropic inhibitory receptors, betaine, L-carnitine, L-arginine, etc. Conclusions Obtained results demonstrate that ammonium ions accelerate neuronal networks firing, implicating ionotropic glutamate receptors, having preserved the activities of group of inhibitory ionotropic and metabotropic receptors. This may mean, that ammonia

  3. Ion-chromatographic behavior of alkali metal cations and ammonium ion on zirconium-adsorbing silica gel.

    PubMed

    Ohta, K; Morikawa, H; Tanaka, K; Uwamino, Y; Furukawa, M; Sando, M

    2000-07-07

    The preparation and evaluation of zirconium-adsorbing silica gel (Zr-Silica) as an ion-exchange stationary phase in ion chromatography for inorganic anions and cations was carried out. The Zr-Silica was prepared by the reaction of silanol groups on the surface of the silica gel with zirconium butoxide (Zr(OCH2CH2CH2CH3)4) in ethanol. The ion-exchange characteristics of the Zr-Silica were evaluated using 10 mM tartaric acid at pH 2.5 as eluent. The Zr-Silica was found to act as a cation-exchanger under the eluent conditions. The retention behavior of alkali and alkaline earth metal cations was then investigated. The Zr-Silica column was proved to be suitable for the simultaneous separation of alkali metal cations and ammonium ion. Excellent separation of the cations on a 15 cm Zr-Silica column was achieved in 25 min using 10 mM tartaric acid as eluent.

  4. Strategic feeding of ammonium and metal ions for enhanced GLA-rich lipid accumulation in Cunninghamella bainieri 2A1.

    PubMed

    Shuib, Shuwahida; Nawi, Wan Nazatul Naziah Wan; Taha, Ekhlass M; Omar, Othman; Kader, Abdul Jalil Abdul; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

    2014-01-01

    Strategic feeding of ammonium and metal ions (Mg(2+), Mn(2+), Fe(3+), Cu(2+), Ca(2+), Co(2+), and Zn(2+)) for enhanced GLA-rich lipid accumulation in C. bainieri 2A1 was established. When cultivated in nitrogen-limited medium, the fungus produced up to 30% lipid (g/g biomass) with 12.9% (g/g lipid) GLA. However, the accumulation of lipid stopped at 48 hours of cultivation although glucose was abundant. This event occurred in parallel to the diminishing activity of malic enzyme (ME), fatty acid synthase (FAS), and ATP citrate lyase (ACL) as well as the depletion of metal ions in the medium. Reinstatement of the enzymes activities was achieved by feeding of ammonium tartrate, but no increment in the lipid content was observed. However, increment in lipid content from 32% to 50% (g/g biomass) with 13.2% GLA was achieved when simultaneous feeding of ammonium, glucose, and metal ions was carried out. This showed that the cessation of lipid accumulation was caused by diminishing activities of the enzymes as well as depletion of the metal ions in the medium. Therefore, strategic feeding of ammonium and metal ions successfully reinstated enzymes activities and enhanced GLA-rich lipid accumulation in C. bainieri 2A1.

  5. Strategic Feeding of Ammonium and Metal Ions for Enhanced GLA-Rich Lipid Accumulation in Cunninghamella bainieri 2A1

    PubMed Central

    Wan Nawi, Wan Nazatul Naziah; Taha, Ekhlass M.; Omar, Othman; Abdul Kader, Abdul Jalil; Kalil, Mohd Sahaid; Abdul Hamid, Aidil

    2014-01-01

    Strategic feeding of ammonium and metal ions (Mg2+, Mn2+, Fe3+, Cu2+, Ca2+, Co2+, and Zn2+) for enhanced GLA-rich lipid accumulation in C. bainieri 2A1 was established. When cultivated in nitrogen-limited medium, the fungus produced up to 30% lipid (g/g biomass) with 12.9% (g/g lipid) GLA. However, the accumulation of lipid stopped at 48 hours of cultivation although glucose was abundant. This event occurred in parallel to the diminishing activity of malic enzyme (ME), fatty acid synthase (FAS), and ATP citrate lyase (ACL) as well as the depletion of metal ions in the medium. Reinstatement of the enzymes activities was achieved by feeding of ammonium tartrate, but no increment in the lipid content was observed. However, increment in lipid content from 32% to 50% (g/g biomass) with 13.2% GLA was achieved when simultaneous feeding of ammonium, glucose, and metal ions was carried out. This showed that the cessation of lipid accumulation was caused by diminishing activities of the enzymes as well as depletion of the metal ions in the medium. Therefore, strategic feeding of ammonium and metal ions successfully reinstated enzymes activities and enhanced GLA-rich lipid accumulation in C. bainieri 2A1. PMID:24991637

  6. Physicochemical properties and ion-solvent interactions in aqueous sodium, ammonium, and lead acetate solution

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Mendkudle, M. S.

    2014-09-01

    Densities (ρ), viscosities (η) and refractive indices ( n D) of aqueous sodium acetate (SA), ammonium acetate (AA), and lead acetate (LA) solutions have been measured for different concentrations of salts at 302.15 K. Apparent molar volumes (φv) for studied solutions were calculated from density data, and fitted to Masson's relation and partial molar volume (φ{v/o}) was determined. Viscosity data were fitted to Jones-Dole equation and viscosity A- and B-coefficients were determined. Refractive index and density data were fitted to Lorentz and Lorenz equation and specific refraction ( R D) were calculated. Behavior of various physicochemical properties indicated presence of strong ion-solvent interactions in present systems and the acetate salts structure maker in water.

  7. Induced binding of proteins by ammonium sulfate in affinity and ion-exchange column chromatography.

    PubMed

    Arakawa, Tsutomu; Tsumoto, Kouhei; Ejima, Daisuke; Kita, Yoshiko; Yonezawa, Yasushi; Tokunaga, Masao

    2007-04-10

    In general, proteins bind to affinity or ion-exchange columns at low salt concentrations, and the bound proteins are eluted by raising the salt concentration, changing the solvent pH, or adding competing ligands. Blue-Sepharose is often used to remove bovine serum albumin (BSA) from samples, but when we applied BSA to Blue-Sepharose in 20 mM phosphate, pH 7.0, 50%-60% of the protein flowed through the column; however, complete binding of BSA was achieved by the addition of 2 M ammonium sulfate (AS) to the column equilibration buffer and the sample. The bound protein was eluted by decreasing the AS concentration or by adding 1 M NaCl or arginine. AS at high concentrations resulted in binding of BSA even to an ion-exchange column, Q-Sepharose, at pH 7.0. Thus, although moderate salt concentrations elute proteins from Blue-Sepharose or ion-exchange columns, proteins can be bound to these columns under extreme salting-out conditions. Similar enhanced binding of proteins by AS was observed with an ATP-affinity column.

  8. Regulation of renin release by calcium and ammonium ions in normal man.

    PubMed

    Kisch, E S; Dluhy, R G; Williams, G H

    1976-12-01

    The effect of infusing calcium chloride, magnesium sulfate, sodium lactate, and ammonium chloride on renin secretion was compared to equimolar infusions of hypotonic and normal saline in sodium-deplete normal subjects. The infusion of 75 mEq of ammonium chloride for 60 min in 6 normal, sodium-deplete subjects suppressed plasma renin activity significantly (P less than 0.01) from 4.4 +/- 0.8 to 2.1 +/- 0.2 ng/ml/h, an effect comparable to that produced by normal saline. Sodium lactate (75 mEq sodium/hr) also significantly reduced renin levels at 20-30 min (P less than 0.01). The infusion of 1/3 normal saline (25 mEq sodium/h for 2 h) produced a significant reduction (P less than 0.01) in plasma renin activity (from control levels of 5.2 +/- 0.8 to 3.1 +/- 0.6 ng/ml/h at 90 min). On the other hand, comparable infusions of 50 mEq of magnesium sulfate over 2 h had no effect on renin release (4.6 +/- 0.8 to 4.6 +/- 0.9 ng/ml/h at 2 h), while the infusion of calcium chloride produced an intermediate reduction (5.2 +/- 1.2 to 3.7 +/- 0.8 ng/ml/h at 2 h (P less than 0.05). The observed effects of the hydrogen and calcium ions on suppressing renin release may be secondary to their known actions on renal sodium excretion. Since the infusions of calcium and hydrogen ions both result in an increased delivery of sodium to the distal segment of the nephron, the results may reflect the regulation of renin by the macula densa, a sensitive intrarenal sensor of renal tubular sodium.

  9. Two di­alkyl­ammonium salts of 2-amino-4-nitro­benzoic acid: crystal structures and Hirshfeld surface analysis

    PubMed Central

    Wardell, James L.; Jotani, Mukesh M.; Tiekink, Edward R. T.

    2016-01-01

    The crystal structures of two ammonium salts of 2-amino-4-nitro­benzoic acid are described, namely di­methyl­aza­nium 2-amino-4-nitro­benzoate, C2H8N+·C7H5N2O4 −, (I), and di­butyl­aza­nium 2-amino-4-nitro­benzoate, C8H20N+·C7H5N2O4 −, (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl­ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti­periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl­ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra­molecular amino-N—H⋯O(carboxyl­ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra­molecular chain by charge-assisted amine-N—H⋯O(carboxyl­ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N—H⋯O(carboxyl­ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N—O⋯π(arene) and methyl-C—H⋯O(nitro) inter­actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N—H⋯O(carboxyl­ate) hydrogen bonding. The formation of ammonium

  10. UREA/ammonium ion removal system for the orbiting frog otolith experiment. [ion exchange resins for water treatment during space missions

    NASA Technical Reports Server (NTRS)

    Schulz, J. R.; Anselmi, R. T.

    1976-01-01

    The feasibility of using free urease enzyme and ANGC-101 ion exchange resin to remove urea and ammonium ion for space system waste water applications was studied. Specifically examined is the prevention of urea and ammonia toxicity in a 30-day Orbiting Frog Otolith (OFO) flight experiment. It is shown that free urease enzyme used in conjunction with ANGC-101 ion-exchange resin and pH control can control urea and amonium ion concentration in unbuffered recirculating water. In addition, the resin does not adversely effect the bullfrogs by lowering the concentration of cations below critical minimum levels. Further investigations on bioburden control, frog waste excretion on an OFO diet, a trade-off analysis of methods of automating the urea/ammonium ion removal system and fabrication and test of a semiautomated breadboard were recommended as continuing efforts. Photographs of test equipment and test animals are shown.

  11. Regioselective organocatalysis: a theoretical prediction of the selective rate acceleration of the SN2 reaction between an acetate ion and primary alkyl chlorides in DMSO solution.

    PubMed

    Pliego, Josefredo R

    2006-05-07

    High level ab initio calculations, including the solvent effect through a continuum solvation model, predict that 1,4-benzenedimethanol is able to catalyse the S(N)2 reaction between an acetate ion and primary alkyl chlorides in dimethyl sulfoxide solution. The catalysis takes place through two selective hydrogen bonds to the transition state. However, for secondary alkyl chlorides the catalysis is not effective due to steric repulsion and desolvation. This effect induces regioselective control of S(N)2 esterification reactions.

  12. Combination of ion exchange and partial nitritation/Anammox process for ammonium removal from mainstream municipal wastewater.

    PubMed

    Malovanyy, Andriy; Plaza, Elzbieta; Trela, Jozef; Malovanyy, Myroslav

    2014-01-01

    In this study, a new technology of nitrogen removal from mainstream municipal wastewater is proposed. It is based on ammonium removal by ion exchange and regeneration of ion exchange material with 10-30 g/L NaCl solution with further nitrogen removal from spent regenerant by partial nitritation/Anammox process. Influence of regenerant strength on performance of ion exchange and biological parts of the proposed technology was evaluated. Moreover, the technology was tested in batch mode using pretreated municipal wastewater, strong acid cation (SAC) resin and partial nitritation/Anammox biomass. It was shown that with ion exchange it is possible to remove 99.9% of ammonium from wastewater while increasing the concentration of ammonium in spent regenerant by 18 times. Up to 95% of nitrogen from spent regenerant, produced by regeneration of SAC resin with 10 g/L NaCl solution, was removed biologically by partial nitritation/Anammox biomass. Moreover, the possibilities of integration of the technology into municipal wastewater treatment technology, and the challenges and advantages are discussed.

  13. Optical Constants of the Ammonium Ion: A Potential Ice Product in the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Roush, T. L.; Moore, M. H.; Cook, J. C.

    2008-12-01

    Optical constants, the real and imaginary indices of refraction, are the fundamental values used in a wide variety of radiative transfer models that are relevant to many environments including circumstellar disks, planetary atmospheres, and planetary surfaces. Cook et al. (2007) observed a feature near 2.2 micrometers (um) in the reflectance spectrum of Pluto's moon, Charon. They suggested evidence for both ammonia di- hydrate and ammonia hemi-hydrate on opposite hemispheres of Charon. Moore et al. (2003) discuss the irradiation of N2-CH4-CO ices; mixtures relevant for Pluto, Triton, and a plausible constituent for some Kuiper Belt Objects and Centaurs. One stable product observed after irradiation of the ice mixture is the ammonium ion, NH4+. NH4+ has strong spectral features in the 3-4 um region and weaker overtones near 2.21 and 2.24 um (Moore et al. 2003). The 2.21 um feature is the strongest of the overtone bands and is near the wavelengths observed for Charon. Using the measurements of Moore et al. (2003) the optical constants of NH4+ are estimated and will be available to investigate NH4+ as an alternative candidate for the feature observed on Charon. Moore, M. et al. 2003, Earth Moon Planets, 92, 291-306. Cook, J. et al. 2007, Ap J, 663, 1406-1419.

  14. An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs

    SciTech Connect

    Lee, Kwan -Soo; Spendelow, Jacob Schatz; Choe, Yoong -Kee; Fujimoto, Cy; Kim, Yu Seung

    2016-08-22

    Here, fuel cells are promising devices for clean power generation in a variety of economically and environmentally significant applications. Low-temperature proton exchange membrane (PEM) fuel cells utilizing Nafion require a high level of hydration, which limits the operating temperature to less than 100°C. In contrast, high-temperature PEM fuel cells utilizing phosphoric acid-doped polybenzimidazole can operate effectively up to 180°C; however, these devices degrade when exposed to water below 140°C. Here we present a different class of PEM fuel cells based on quaternary ammonium-biphosphate ion pairs that can operate under conditions unattainable with existing fuel cell technologies. These fuel cells exhibit stable performance at 80–160°C with a conductivity decay rate more than three orders of magnitude lower than that of a commercial high-temperature PEM fuel cell. By increasing the operational flexibility, this class of fuel cell can simplify the requirements for heat and water management, and potentially reduce the costs associated with the existing fully functional fuel cell systems.

  15. An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs

    NASA Astrophysics Data System (ADS)

    Lee, Kwan-Soo; Spendelow, Jacob S.; Choe, Yoong-Kee; Fujimoto, Cy; Kim, Yu Seung

    2016-09-01

    Fuel cells are promising devices for clean power generation in a variety of economically and environmentally significant applications. Low-temperature proton exchange membrane (PEM) fuel cells utilizing Nafion require a high level of hydration, which limits the operating temperature to less than 100 ∘C. In contrast, high-temperature PEM fuel cells utilizing phosphoric acid-doped polybenzimidazole can operate effectively up to 180 ∘C however, these devices degrade when exposed to water below 140 ∘C. Here we present a different class of PEM fuel cells based on quaternary ammonium-biphosphate ion pairs that can operate under conditions unattainable with existing fuel cell technologies. These fuel cells exhibit stable performance at 80-160 ∘C with a conductivity decay rate more than three orders of magnitude lower than that of a commercial high-temperature PEM fuel cell. By increasing the operational flexibility, this class of fuel cell can simplify the requirements for heat and water management, and potentially reduce the costs associated with the existing fully functional fuel cell systems.

  16. An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs

    DOE PAGES

    Lee, Kwan -Soo; Spendelow, Jacob Schatz; Choe, Yoong -Kee; ...

    2016-08-22

    Here, fuel cells are promising devices for clean power generation in a variety of economically and environmentally significant applications. Low-temperature proton exchange membrane (PEM) fuel cells utilizing Nafion require a high level of hydration, which limits the operating temperature to less than 100°C. In contrast, high-temperature PEM fuel cells utilizing phosphoric acid-doped polybenzimidazole can operate effectively up to 180°C; however, these devices degrade when exposed to water below 140°C. Here we present a different class of PEM fuel cells based on quaternary ammonium-biphosphate ion pairs that can operate under conditions unattainable with existing fuel cell technologies. These fuel cells exhibitmore » stable performance at 80–160°C with a conductivity decay rate more than three orders of magnitude lower than that of a commercial high-temperature PEM fuel cell. By increasing the operational flexibility, this class of fuel cell can simplify the requirements for heat and water management, and potentially reduce the costs associated with the existing fully functional fuel cell systems.« less

  17. Novel hierarchical three-dimensional ammonium vanadate nanowires electrodes for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Fang, Dong; Cao, Yunhe; Liu, Ruina; Xu, Weilin; Liu, Suqin; Luo, Zhiping; Liang, Chaowei; Liu, Xiaoqing; Xiong, Chuanxi

    2016-01-01

    Ammonium vanadate (NH4V4O10) nanowire flowers and nanowires on titanium (Ti) foils are synthesized by hexamethylenetetramine (HMTA)-assisted hydrothermal reactions as a cathode material for lithium-ion battery. The as-prepared NH4V4O10 nanowires are about 50 nm in diameter and several micrometers in length. The effects of reaction time, temperature and additive concentration on the resulting morphology are investigated. Reversible lithium intercalation behavior of the nanowires has been evaluated by cyclic voltammetry and galvanostatic discharge⿿charge cycling. The NH4V4O10 nanowires on Ti foil deliver a high discharge capacity of 168.5 mA h g⿿1 after 100 cycles between 2.0 and 4.0 V at 50 mA g⿿1. A high rate capability is obtained with a remaining discharge capacity of about 182.6 mA h g⿿1 after 35 cycles at various rates. Further, the NH4V4O10 nanowires on Ti foil have a higher discharge capacity of 330.5 mA h g⿿1 after 100 cycles at 0.8⿿4.0 V at 50 mA g⿿1.

  18. The adsorption of alkyl-dimethyl-benzyl-ammonium chloride onto cotton nonwoven hydroentangled substrates at the solid-liquid interface is minimized by additive chemistries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quaternary ammonium compounds, commonly referred to as quats, are cationic surfactants widely used as the active biocide ingredient for disposable disinfecting wipes. The cationic nature of quats results in a strong ionic interaction and adsorption onto wipes materials that have an anionic surface ...

  19. New insight into the nanostructure of ionic liquids: a small angle X-ray scattering (SAXS) study on liquid tri-alkyl-methyl-ammonium bis(trifluoromethanesulfonyl)amides and their mixtures.

    PubMed

    Pott, Tanja; Méléard, Philippe

    2009-07-14

    We report a small angle X-ray scattering study on the liquid phase of a series of room temperature ionic liquids and their binary mixtures. The ionic liquids studied belong to the tri-alkyl-methyl-ammonium family with bis(trifluoromethanesulfonyl)amide as the anion and were studied as a function of alkyl chain length. These ionic liquids were found to exhibit marked nanoscale ordering in their isotropic liquid state as judged from the small angle X-ray scattering. The observed structural ordering is of supramolecular order and depends strongly on the length of the cation hydrophobic side chain. Moreover, the data can be analyzed on the basis of a disordered smectic A phase, consisting of strongly interdigitated bilayers that sequester the ionic liquid into polar and hydrophobic regions. These findings were also found to be consistent with density data of these molten salts. Additionally, we demonstrate that this experimentally observed nanostructuring can further be fine-tuned using binary mixtures.

  20. The Soret absorption band of isolated chlorophyll a and b tagged with quaternary ammonium ions.

    PubMed

    Stockett, Mark H; Musbat, Lihi; Kjær, Christina; Houmøller, Jørgen; Toker, Yoni; Rubio, Angel; Milne, Bruce F; Brøndsted Nielsen, Steen

    2015-10-21

    We have performed gas-phase absorption spectroscopy in the Soret-band region of chlorophyll (Chl) a and b tagged by quaternary ammonium ions together with time-dependent density functional theory (TD-DFT) calculations. This band is the strongest in the visible region of metalloporphyrins and an important reporter on the microenvironment. The cationic charge tags were tetramethylammonium, tetrabutylammonium, and acetylcholine, and the dominant dissociation channel in all cases was breakage of the complex to give neutral Chl and the charge tag as determined by photoinduced dissociation mass spectroscopy. Two photons were required to induce fragmentation on the time scale of the experiment (microseconds). Action spectra were recorded where the yield of the tag as a function of excitation wavelength was sampled. These spectra are taken to represent the corresponding absorption spectra. In the case of Chl a we find that the tag hardly influences the band maximum which for all three tags is at 403 ± 5 nm. A smaller band with maximum at 365 ± 10 nm was also measured for all three complexes. The spectral quality is worse in the case of Chl b due to lower ion beam currents; however, there is clear evidence for the absorption being to the red of that of Chl a (most intense peak at 409 ± 5 nm) and also a more split band. Our results demonstrate that the change in the Soret-band spectrum when one peripheral substituent (CH3) is replaced by another (CHO) is an intrinsic effect. First principles TD-DFT calculations agree with our experiments, supporting the intrinsic nature of the difference between Chl a and b and also displaying minimal spectral changes when different charge tags are employed. The deviations between theory and experiment have allowed us to estimate that the Soret-band absorption maxima in vacuo for the neutral Chl a and Chl b should occur at 405 nm and 413 nm, respectively. Importantly, the Soret bands of the isolated species are significantly blueshifted

  1. Preparation of immunoglobulin Y from egg yolk using ammonium sulfate precipitation and ion exchange chromatography.

    PubMed

    Ko, K Y; Ahn, D U

    2007-02-01

    The objective of this study was to develop an economical, simple, and large-scale separation method for IgY from egg yolk. Egg yolk diluted with 9 volumes of cold water was centrifuged after adjusting the pH to 5.0. The supernatant was added with 0.01% charcoal or 0.01% carrageenan and centrifuged at 2,800 x g for 30 min. The supernatant was filtered through a Whatman no. 1 filter paper and then the filtrate was concentrated to 20% original volume using ultrafiltration. The concentrated solution was further purified using either cation exchange chromatography or ammonium sulfate precipitation. For the cation exchange chromatography method, the concentrated sample was loaded onto a column equilibrated with 20 mM citrate-phosphate buffer at pH 4.8 and eluted with 200 mM citrate-phosphate buffer at pH 6.4. For the ammonium sulfate precipitation method, the concentrated sample was twice precipitated with 40% ammonium sulfate solution at pH 9.0. The yield and purity of IgY were determined by ELISA and electrophoresis. The yield of IgY from the cation exchange chromatography method was 30 to 40%, whereas that of the ammonium sulfate precipitation was 70 to 80%. The purity of IgY from the ammonium sulfate method was higher than that of the cation exchange chromatography. The cation exchange chromatography could handle only a small amount of samples, whereas the ammonium sulfate precipitation could handle a large volume of samples. This suggests that ammonium sulfate precipitation was a more efficient and useful purification method than cation exchange chromatography for the large-scale preparation of IgY from egg yolk.

  2. DDQ-promoted dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones by a radical ion mechanism.

    PubMed

    Ding, Ye; Huang, Zhangjian; Yin, Jian; Lai, Yisheng; Zhang, Shibo; Zhang, Zhiguo; Fang, Lei; Peng, Sixun; Zhang, Yihua

    2011-09-07

    A novel and facile DDQ-mediated dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones is described. The formation of lactones proceeds by a radical ion mechanism, which has been established by DPPH˙-mediated chemical identification, ESR spectroscopy and an enol intermediate trapping.

  3. Atomic emission spectrometric determination of ephedrine, cinchonine, chlorpheniramine, atropine and diphenhydramine based on formation of ion associates with ammonium reineckate.

    PubMed

    Khalil, S

    1999-12-01

    Ion-associate complexes of ephedrine HCl (I), cinchonine HCl (II), chlorpheniramine maleate (III), atropine sulphate (IV) and diphenhydramine HCl (V) with ammonium reineckate were precipitated and their solubilities were studied as a function of pH, ionic strength and temperature. Saturated solutions of each ion-associate under the optimum precipitation conditions were prepared and the Cr ion content in the supernatant was determined. The solubility products were thus elucidated at different temperatures. A new accurate and precise method using direct current plasma-atomic emission spectrometry for the determination of the investigated drugs in pure solutions and in pharmaceutical preparations is described. The drugs can determined by the present method in the ranges 1.6-52,2.64-85.8,3.12-101.4,5.52-180.4 and 2.72-75.85 microg/ml solutions of I, II, III, IV and V, respectively.

  4. Gas chromatography with tandem differential mobility spectrometry of fatty acid alkyl esters and the selective detection of methyl linolenate in biodiesels by dual-stage ion filtering.

    PubMed

    Pasupuleti, D; Pierce, K; Eiceman, G A

    2015-11-20

    Alkyl esters of fatty acids (FAAEs) with carbon numbers from 8 to 20 formed protonated monomers and proton bound dimers through atmospheric pressure chemical ionization reactions and these gas ions were characterized for their field dependent mobility coefficients using differential mobility spectrometry (DMS). Separation of ion peaks with a vapor modifier was achieved for ions with masses of 317-1033 Da though the differences in these coefficients and the resolution of ion peaks decreased proportionally with increased ion mass. Differences in dispersion curves were sufficient to isolate ions from specific FAAEs in the effluent of a gas chromatograph by dual stage ion filtering using a tandem DMS detector. Methyl linolenate was isolated from nearby eluting methyl oleate, methyl stearate and methyl linoleate within analysis times of 10s without measureable complications from charge suppression in the ion source or leakage in filtering of ions with close proximity of dispersion behavior.

  5. Physicochemical characteristics and sorption capacities of heavy metal ions of activated carbons derived by activation with different alkyl phosphate triesters

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Liu, Hai; Yang, Shaokun; Zhang, Jian; Zhang, Chenglu; Wu, Haiming

    2014-10-01

    Five alkyl phosphate triesters (APTEs), including trimethyl phosphate (TMP), triethyl phosphate (TEP), triisopropyl phosphate (TPP), tributyl phosphate (TBP) and trioctyl phosphate (TOP), were used as activating agents for preparing activated carbons (AC-APTEs) with high surface acidity and metal ion sorption capacity. N2 adsorption/desorption isotherms, surface morphologies, elemental compositions, results of Boehm's titration and sorption capacities of heavy metal ions of the carbons were investigated. AC-APTEs contained much more acidic groups and exhibited much less surface area (<500 m2/g) in comparison with activated carbon (AC-PPA, 1145 m2/g) obtained from phosphoric acid activation. For the AC-APTEs, AC-TOP had the highest surface area (488 m2/g), AC-TMP showed the highest yield (41.1%), and AC-TBP possessed the highest acidic groups (2.695 mmol/g), oxygen content (47.0%) and metal ion sorption capacities (40.1 mg/g for Ni(II) and 53.5 mg/g for Cd(II)). For the carbons, AC-APTEs showed much larger Ni(II) and Cd(II) sorption capacities than AC-PPA, except AC-TPP. The differences of the carbons in the physicochemical and sorption properties suggested surface chemistry of the carbons was the main factor influencing their sorption capacities whereas the pore structure played a secondary role.

  6. Analysis of an explosion accident of nitrogen trichloride in a waste liquid containing ammonium ion and platinum black.

    PubMed

    Okada, Ken; Akiyoshi, Miyako; Ishizaki, Keiko; Sato, Hiroyasu; Matsunaga, Takehiro

    2014-08-15

    Five liters of sodium hypochlorite aqueous solution (12 mass%) was poured into 300 L of liquid waste containing ammonium ion of about 1.8 mol/L in a 500 L tank in a plant area; then, two minutes later the solution exploded with a flash on March 30th, 2005. The tank cover, the fluorescent lamp and the air duct were broken by the blast wave. Thus, we have conducted 40 runs of laboratory-scale explosion tests under various conditions (solution concentrations of (NH4)2SO4 and NaClO, temperatures, Pt catalysts, pH, etc.) to investigate the causes for such an explosion. When solutions of ammonium sulfate and sodium hypochlorite are mixed in the presence of platinum black, explosions result. This is ascribable to the formation of explosive nitrogen trichloride (NCl3). In the case where it is necessary to mix these 2 solutions (ammonium sulfate and sodium hypochlorite) in the presence of platinum black, the following conditions would reduce a probability of explosion; the initial concentration of NH4(+) should be less than 3 mol/L and the pH should be higher than 6. The hypochlorite solution (in 1/10 in volume) to be added at room temperature is recommended to be less than 0.6 mol/L.

  7. Spectroscopic study on interaction between three cationic surfactants with different alkyl chain lengths and DNA.

    PubMed

    Guo, Lili; Zhang, Zhaohong; Qiao, Heng; Liu, Miao; Shen, Manli; Yuan, Tianxin; Chen, Jing; Dionysiou, Dionysios D

    2015-01-01

    In this study, the interaction between cationic surfactants with different alkyl chain lengths, such as hexyltrimethyl ammonium bromide (HTAB), dodecyltrimethyl ammonium bromide (DTAB) and cetyltrimethyl ammonium bromide (CTAB), and DNA was investigated by UV-vis spectroscopy, fluorescence spectroscopy and viscosity techniques. The results showed that these three cationic surfactants with different hydrocarbon chain lengths could all interact with DNA. Their binding modes were estimated and their interaction strength was compared. In addition, the effects of the surfactant, NaCl and phosphate ion concentrations on the interaction were reviewed. It is wished that this work would provide some valuable references to investigate the influence of cationic surfactants with different alkyl chain lengths on DNA.

  8. First in-situ detection of the cometary ammonium ion NH_4+ (protonated ammonia NH3) in the coma of 67P/C-G near perihelion

    NASA Astrophysics Data System (ADS)

    Beth, A.; Altwegg, K.; Balsiger, H.; Berthelier, J.-J.; Calmonte, U.; Combi, M. R.; De Keyser, J.; Dhooghe, F.; Fiethe, B.; Fuselier, S. A.; Galand, M.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Hässig, M.; Héritier, K. L.; Kopp, E.; Le Roy, L.; Mandt, K. E.; Peroy, S.; Rubin, M.; Sémon, T.; Tzou, C.-Y.; Vigren, E.

    2017-01-01

    In this paper, we report the first in-situ detection of the ammonium ion NH_4+ at 67P/Churyumov-Gerasimenko (67P/C-G) in a cometary coma, using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) / Double Focusing Mass Spectrometer (DFMS). Unlike neutral and ion spectrometers onboard previous cometary missions, the ROSINA/DFMS spectrometer, when operated in ion mode, offers the capability to distinguish NH_4+ from H2O+ in a cometary coma. We present here the ion data analysis of mass-to-charge ratios 18 and 19 at high spectral resolution and compare the results with an ionospheric model to put the these results into context. The model confirms that the ammonium ion NH_4+ is one of the most abundant ion species, as predicted, in the coma near perihelion.

  9. Cesium removal from liquid acidic wastes with the primary focus on ammonium molybdophosphate as an ion exchanger: A literature review

    SciTech Connect

    Miller, C.J.

    1995-03-01

    Many articles have been written concerning the selective removal of cesium from both acidic and alkaline defense wastes. The majority of the work performed for cesium removal from defense wastes involves alkaline feed solutions. Several different techniques for cesium removal from acidic solutions have been evaluated such as precipitation, solvent extraction, and ion exchange. The purpose of this paper is to briefly review various techniques for cesium removal from acidic solutions. The main focus of the review will be on ion exchange techniques, particularly those involving ammonium molybdophosphate as the exchanger. The pertinent literature sources are condensed into a single document for quick reference. The information contained in this document was used as an aid in determining techniques to evaluate cesium removal from the acidic Idaho Chemical Processing Plant waste matrices. 47 refs., 2 tabs.

  10. [EFfect of quinazolone-alkyl-carboxylic acid derivatives on the transmembrane Ca2+ ion flux mediated by AMPA receptors].

    PubMed

    Szárics, Eva; LaszTóczi, Bálint; Nyikos, Lajos; Barabás, Péter; Kovács, Ilona; Skuban, Nina; Nagy, Péter I; Kökösi, József; Takácsné, Novák Krisztina; Kardos, Julianna

    2002-01-01

    The excitatory neurotransmitter, Glu, plays a crucial role in many sensory and motor functions as well as in brain development, learning and memory and it is also involved in the pathogenesis of a number of neurological disorders, including epilepsy, Alzheimer's and Parkinson's diseases. Therefore, the study of Glu receptors (GluRs) is of therapeutical importance. We showed here by fluorescence monitoring of transmembrane Ca2+ ion fluxes in response to (S)-alpha-amino-3-hidroxi-5-metil-4-izoxazol propionic acid ((S)-AMPA) on the time scale of 0.00004-10 s that Ca2+ ion influx proceeds through faster and slower desensitizing receptors. Pharmacological isolation of the slower and faster desensitizing AMPA receptor was possible by fluorescence monitoring of Ca2+ ion translocation in response to (S)-AMPA in the presence and absence of various 2-methyl-4-oxo-3H-quinazoline-3-alkyl-carboxilic acid derivatives (Qxs): the acetic acid Q1 inhibits the slower desensitizing receptor response specifically, while the acetyl-piperidine Q5 is a more potent inhibitor of the faster desensitizing receptor response. In addition, spontaneous interictal activity, as induced by high [K+] conditions in hippocampal slices, was reduced significantly by Q5, suggesting a possible anticonvulsant property of Q5. Substitutions of Qxs into the GluR2 S1S2 binding core were consistent with their effect by causing variable degree of S1S2 bridging interaction as one of the main determinants of AMPA receptor agonist activity. The exploitation of differences between similar receptors will be important in the development and use of drugs with high pharmacological specificity.

  11. Spontaneous intercalation of long-chain alkyl ammonium into edge-selectively oxidized graphite to efficiently produce high-quality graphene

    PubMed Central

    Wei, Liangming; Wu, Fei; Shi, Diwen; Hu, Changchen; Li, Xiaolin; Yuan, Weien; Wang, Jian; Zhao, Jiang; Geng, Huijuan; Wei, Hao; Wang, Ying; Hu, Nantao; Zhang, Yafei

    2013-01-01

    Mass production of high-quality graphene nanosheets (GNs) is essential for practical applications. We report that oxidation of graphite by low concentration KMnO4 at relatively high temperature (60°C) leads to edge-selectively oxidized graphite (EOG) which preserves the high crystalline graphitic structure on its basal planes while the edges are functionalized by oxygen-containing groups. Long-chain tetradecyl-ammonium salt (C14N+) could be spontaneously intercalated into EOG to form intercalated EOG-C14N+ compounds. Gentle and short-time sonication of EOG-C14N+ in toluene can full exfoliate EOG into edge-oxidized graphene nanosheets (EOGNs) with concentration of 0.67 mg/ml, monolayer population up to 90% and lateral size from 1 μm to >100 μm. The EOG and EOGN films show excellent electrical conductance, which is far superior to their graphene oxide (GO) counterparts. Our method provides an efficient way to produce high-quality GNs, and the resultant EOG also can be directly used for production of multifunctional materials and devices. PMID:24022463

  12. Sorption of doubly charged metal ions from ammonium fluoride solutions by KFP-23 cation-exchange resin

    SciTech Connect

    Ganyaev, V.P.; Pimneva, L.A.; Pakholkov, V.S.

    1982-10-20

    This report examines the results of a study of sorption of a number of doubly charged cations by the macroporous cation-exchange KFP-12 from 0.1 N MeF/sub 2/ solutions containing NH/sub 4/F in concentrations from 0 to 3.0 M. As the result of an investigation of the sorption, under dynamic conditions, of copper, zinc, cadmium, manganese, cobalt, and nickel ions from ammonium fluoride solutions by KFP-12 cation-exchange resin in the influence of the ionic form (H/sup +/ or NH/sub 4//sup +/) of the resin and of the NH/sub 4/F concentration on the degree of sorption and on the breakthrough capacity was established. The character of bonding and coordination of the sorbed cations with the ionic groups of the resin has been established. The possibilty of thorough purification of ammonium fluoride and (NH/sub 4/)/sub 2/BeF/sub 4/ solutions with the aid of KFP-12 resin in NH/sub 4//sup +/ form has been demonstrated. The purification co-efficients were calculated.

  13. Extraction of manganese by alkyl monocarboxylic acid in a mixed extractant from a leaching solution of spent lithium-ion battery ternary cathodic material

    NASA Astrophysics Data System (ADS)

    Joo, Sung-Ho; Shin, Dongju; Oh, ChangHyun; Wang, Jei-Pil; Shin, Shun Myung

    2016-02-01

    We investigate the separation of manganese by an antagonistic effect from a leaching solution of ternary cathodic material of spent lithium-ion batteries that contain 11,400 mg L-1 Co, 11,700 mg L-1 Mn, 12,200 mg L-1 Ni, and 5300 mg L-1 Li using a mixture of alkyl monocarboxylic acid and di-(2-ethylhexyl)phosphoric acid extractants. pH isotherm, distribution coefficient, separation factor, McCabe-Thiele diagram, selective scrubbing, and countercurrent extraction tests are carried out to prove an antagonistic effect and to recover manganese using alkyl monocarboxylic in the mixed extractant. Slope analysis is used to determine the extraction mechanism between a mixture of extractants and valuable metals. An increasing concentration of alkyl monocarboxylic acid in the mixture of extractants results in a decrease in distribution coefficient of cobalt and manganese, however, the separation factor value (β(Mn/Co)) increases at pH 4.5. This is caused by slope analysis where alkyl monocarboxylic acid disrupts the extraction mechanism between di-(2-ethylhexyl)phosphoric acid and cobalt. Finally, continuous countercurrent extraction in a mini-plant test demonstrate the feasibility of manganese recovery from cobalt, nickel, and lithium.

  14. Ion chromatography with the indirect ultraviolet detection of alkali metal ions and ammonium using imidazolium ionic liquid as ultraviolet absorption reagent and eluent.

    PubMed

    Liu, Yong-Qiang; Yu, Hong

    2016-08-01

    Indirect ultraviolet detection was conducted in ultraviolet-absorption-agent-added mobile phase to complete the detection of the absence of ultraviolet absorption functional group in analytes. Compared with precolumn derivatization or postcolumn derivatization, this method can be widely used, has the advantages of simple operation and good linear relationship. Chromatographic separation of Li(+) , Na(+) , K(+) , and NH4 (+) was performed on a carboxylic acid base cation exchange column using imidazolium ionic liquid/acid/organic solvent as the mobile phase, in which imidazolium ionic liquids acted as ultraviolet absorption reagent and eluting agent. The retention behaviors of four kinds of cations are discussed, and the mechanism of separation and detection are described. The main factors influencing the separation and detection were the background ultraviolet absorption reagent and the concentration of hydrogen ion in the ion chromatography-indirect ultraviolet detection. The successful separation and detection of Li(+) , Na(+) , K(+) , and NH4 (+) within 13 min was achieved using the selected chromatographic conditions, and the detection limits (S/N = 3) were 0.02, 0.11, 0.30, and 0.06 mg/L, respectively. A new separation and analysis method of alkali metal ions and ammonium by ion chromatography with indirect ultraviolet detection method was developed, and the application range of ionic liquid was expanded.

  15. Simulated Solvation of Organic Ions II: Study of Linear Alkylated Carboxylate Ions in Water Nanodrops and in Liquid Water. Propensity for Air/Water Interface and Convergence to Bulk Solvation Properties.

    PubMed

    Houriez, Céline; Meot-Ner Mautner, Michael; Masella, Michel

    2015-09-10

    We investigated the solvation of carboxylate ions from formate to hexanoate, in droplets of 50 to 1000 water molecules and neat water, by computations using standard molecular dynamics and sophisticated polarizable models. The carboxylate ions from methanoate to hexanoate show strong propensity for the air/water interface in small droplets. Only the ions larger than propanoate retain propensity for the interface in larger droplets, where their enthalpic stabilization by ion/water dispersion is reduced there by 3 kcal mol(-1) per CH2 group. This is compensated by entropy effects over +3.3 cal mol(-1) K(-1) per CH2 group. On the surface, the anionic headgroups are strongly oriented toward the aqueous core, while the hydrophobic alkyl chains are repelled into air and lose their structure-making effects. These results reproduce the structure-making effects of alkyl groups in solution, and suggest that the hydrocarbon chains of ionic headgroups and alkyl substituents solvate independently. Extrapolation to bulk solution using standard extrapolation schemes yields absolute carboxylate solvation energies. The results for formate and acetate yield a proton solvation enthalpy of about 270 kcal mol(-1), close to the experiment-based value. The largest carboxylate ions yield a value smaller by about 10 kcal mol(-1), which requires studies in much larger droplets.

  16. Nitrate and ammonium ions removal from groundwater by a hybrid system of zero-valent iron combined with adsorbents.

    PubMed

    Ji, Min-Kyu; Park, Won-Bae; Khan, Moonis Ali; Abou-Shanab, Reda A I; Kim, Yongje; Cho, Yunchul; Choi, Jaeyoung; Song, Hocheol; Jeon, Byong-Hun

    2012-04-01

    Nitrate (NO(3)(-)) is a commonly found contaminant in groundwater and surface water. It has created a major water quality problem worldwide. The laboratory batch experiments were conducted to investigate the feasibility of HCl-treated zero-valent iron (Fe(0)) combined with different adsorbents as hybrid systems for simultaneous removal of nitrate (NO(3)(-)) and ammonium (NH(4)(+)) ions from aqueous solution. The maximum NO(3)(-) removal in combined Fe(0)-granular activated carbon (GAC), Fe(0)-filtralite and Fe(0)-sepiolite systems was 86, 96 and 99%, respectively, at 45 °C for 24 h reaction time. The NO(3)(-) removal rate increased with the increase in initial NO(3)(-) concentration. The NO(3)(-) removal efficiency by hybrid systems was in the order of sepiolite > filtralite > GAC. The NH(4)(+) produced during the denitrification process by Fe(0) was successfully removed by the adsorbents, with the removal efficiency in the order of GAC > sepiolite > filtralite. Results of the present study suggest that the use of a hybrid system could be a promising technology for achieving simultaneous removal of NO(3)(-) and NH(4)(+) ions from aqueous solution.

  17. Synthesis and Characterization of Perfluoro Quaternary Ammonium Ion Exchange Membranes for Fuel Cell Applications

    DTIC Science & Technology

    2012-01-01

    TERMS Perfluoroinated polymer; anion exchange membrane; morphology; base stability Mellisa A. Vandiver, Soenke Seifert, Matthew W. Liberatore, Andrew...humidities. Better understanding of the role of water and polymer morphology on the ion conduction and stability of AEMs is necessary for practical AEM fuel...sufficient chemical and mechanical stability (5, 10) For these reasons PFSAs remain the benchmark comparison for all new PEMs and AEMs (1, 11). The

  18. Source apportionment of ammonium and nitrate ion using nitrogen stable isotope

    NASA Astrophysics Data System (ADS)

    Kawashima, H.

    2013-12-01

    Suspended particulate matter (SPM), defined to particle size as 100 % cut-off aerodynamic diameter at 10 μm, has adverse effects on human health. In these years, stable isotope ratio of small sample volume can be analyzed high precision by isotope ratio mass spectrometry coupling with elemental analyzer. Recently some fields are using stable isotope ratio. For environmental field, it is expected such as powerful tool for source identification and understanding mechanism. But the existed researches intended for stable nitrogen isotope (δ15N) of particulate matter have been limited. We try to analysis δ15N-ammonium (δ15N-NH4+) and nitrate (δ15N-NO3-) of SPM, to estimate source of NH4+ and NO3- of SPM. Average δ15N-NH4+ and δ15N-NO3- of SPM in Akita prefecture, Japan were 15.9 ‰ (1.3‰ to 38.5 ‰) and - 0.7 ‰ (-4.6 ‰ to 4.8 ‰), respectively. Although δ15N-NH4+ do not show seasonal trend, δ15N-NO3- increased in winter markedly and decreasing in summer. In generally, the dominant origin of NO3- of SPM is produced from NOx emitted by combustion of some fuel and NO by agriculture source. Heaton (1990) summarized that δ15N-NOx is very different by temperature of combustion. They insisted that δ15N-NOx values are between -13 ‰ to -2 ‰ over 2000 °C (e.g. vehicle engine) and 6 ‰ to 13 ‰ under 1300 °C (e.g. coal combustion). Therefore, the reason of the winter high trend in this study might be combustion process such as coal combustion source. Moreover, the baseline might be made by vehicle sources. In addition, the reason of decreasing in summer seemed to be affected very low δ15N-NO of fertilizer and urea indicated by Li and Wang (2008). Bacteria were activated in summer, and NO from fertilizer and urea was emitted. This summary seemed to be very reasonable.

  19. Sorption of uranium(VI) ions from hydrochloric acid and ammonium chloride solutions by anion exchangers

    SciTech Connect

    Pakholkov, V.S.; Denisova, L.A.; Rychkov, V.N.; Kurnosenko, N.A.

    1988-01-01

    The sorption of macroscopic quantities of uranium from solutions of UO/sub 2/Cl/sub 2/ containing HCl and NH/sub 4/Cl in concentrations from 0.0 to 6.0 M by the AV-17 x 8, AV-16G, EDE-10P, AN-31, AN-2F, AN22, and AN-251 anion exchangers has been investigated under static conditions. The sorption isotherms are described by an equation similar to Freundlich's equation: K/sub d/ = K tilde x C/sub eq/sup 1/z/ or log K/sub d/ = log K tilde + 1/z x log C/sub eq/. Equations describing the dependence of the sorbability (or K/sub d/) on the equilibrium concentration of uranium in the solution have been obtained with the aid of the least-squares method. Conclusions regarding the chemistry of the exchange of uranium ions on anion exchangers in chloride solutions have been drawn on the basis of the UV spectra of the original solutions and the IR spectra of the ion exchangers obtained in this work, as well as the established general laws governing sorption.

  20. Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride-Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes.

    PubMed

    Chun, Jinyoung; Jo, Changshin; Sahgong, Sunhye; Kim, Min Gyu; Lim, Eunho; Kim, Dong Hyeon; Hwang, Jongkook; Kang, Eunae; Ryu, Keun Ah; Jung, Yoon Seok; Kim, Youngsik; Lee, Jinwoo

    2016-12-28

    Metal fluorides (MFx) are one of the most attractive cathode candidates for Li ion batteries (LIBs) due to their high conversion potentials with large capacities. However, only a limited number of synthetic methods, generally involving highly toxic or inaccessible reagents, currently exist, which has made it difficult to produce well-designed nanostructures suitable for cathodes; consequently, harnessing their potential cathodic properties has been a challenge. Herein, we report a new bottom-up synthetic method utilizing ammonium fluoride (NH4F) for the preparation of anhydrous MFx (CuF2, FeF3, and CoF2)/mesoporous carbon (MSU-F-C) nanocomposites, whereby a series of metal precursor nanoparticles preconfined in mesoporous carbon were readily converted to anhydrous MFx through simple heat treatment with NH4F under solventless conditions. We demonstrate the versatility, lower toxicity, and efficiency of this synthetic method and, using XRD analysis, propose a mechanism for the reaction. All MFx/MSU-F-C prepared in this study exhibited superior electrochemical performances, through conversion reactions, as the cathode for LIBs. In particular, FeF3/MSU-F-C maintained a capacity of 650 mAh g(-1)FeF3 across 50 cycles, which is ∼90% of its initial capacity. We expect that this facile synthesis method will trigger further research into the development of various nanostructured MFx for use in energy storage and other applications.

  1. Creatinine and urea biosensors based on a novel ammonium ion-selective copper-polyaniline nano-composite.

    PubMed

    Zhybak, M; Beni, V; Vagin, M Y; Dempsey, E; Turner, A P F; Korpan, Y

    2016-03-15

    The use of a novel ammonium ion-specific copper-polyaniline nano-composite as transducer for hydrolase-based biosensors is proposed. In this work, a combination of creatinine deaminase and urease has been chosen as a model system to demonstrate the construction of urea and creatinine biosensors to illustrate the principle. Immobilisation of enzymes was shown to be a crucial step in the development of the biosensors; the use of glycerol and lactitol as stabilisers resulted in a significant improvement, especially in the case of the creatinine, of the operational stability of the biosensors (from few hours to at least 3 days). The developed biosensors exhibited high selectivity towards creatinine and urea. The sensitivity was found to be 85 ± 3.4 mAM(-1)cm(-2) for the creatinine biosensor and 112 ± 3.36 mAM(-1)cm(-2) for the urea biosensor, with apparent Michaelis-Menten constants (KM,app), obtained from the creatinine and urea calibration curves, of 0.163 mM for creatinine deaminase and 0.139 mM for urease, respectively. The biosensors responded linearly over the concentration range 1-125 µM, with a limit of detection of 0.5 µM and a response time of 15s. The performance of the biosensors in a real sample matrix, serum, was evaluated and a good correlation with standard spectrophotometric clinical laboratory techniques was found.

  2. Determination of ammonium ion by fluorometry or spectrophotometry after on-line derivatization with o-phthalaldehyde

    NASA Technical Reports Server (NTRS)

    Goyal, S. S.; Rains, D. W.; Huffaker, R. C.

    1988-01-01

    A fast, sensitive, simple, and highly reproducible method for routine assay of ammonium ion (NH4+) was developed by using HPLC equipment. The method is based on the reaction of NH4+ with o-phthalaldehyde (OPA) in the presence of 2-mercaptoethanol. After an on-line derivatization, the resulting NH4(+)-OPA product was quantified by using fluorometric or spectrophotometric detection. For fluorometric detection, the excitation and emission wavelengths were 410 and 470 nm, respectively. The spectrophotometric detection was made by measuring absorbance at 410 nm. Results on the effects of OPA-reagent composition and pH, reaction temperature, sample matrix, and linearity of the assay are presented. Even though it took about 2 min from the time of sample injection to the appearance of sample peak, sample injections could be overlapped at an interval of about 1 min. Thus, the actual time needed for analysis was about 1 min per assay. The method can be used in a fully automated mode by using an autosampler injector.

  3. A UHPLC method for the simultaneous analysis of biogenic amines, amino acids and ammonium ions in beer.

    PubMed

    Redruello, Begoña; Ladero, Victor; Del Rio, Beatriz; Fernández, María; Martin, M C; Alvarez, Miguel A

    2017-02-15

    This paper reports a novel UHPLC method for simultaneously quantifying nine biogenic amines, 21 amino acids, and ammonium ions, in beer. Precision values of standard curves slopes were lower than 3.4% and recovery was between 85% and 106%, indicating the absence of matrix effect. Linear calibration curves were obtained for analyte concentrations between two and four orders of magnitude (R(2)>0.996). Repeatability tests returned mean variations of 3.2% and 0.5% for beer and a standard solution, respectively. Sensitivity ranged between 0.03mg/L and 0.63mg/L for the biogenic amines, and 0.05mg/L and 5.19mg/L for other compounds. Original data on the habitual presence of ethanolamine in beers are presented. The method allows for more samples to be assayed per unit time, it uses less solvent than other techniques and therefore reduces costs and the associated waste. It could be a valuable tool for monitoring the safety and quality of beers.

  4. Hydrothermal synthesis and structural characterization of ammonium ion-templated lanthanide(III) carboxylate-phosphonates

    PubMed Central

    Ayi, Ayi A.; Kinnibrugh, Tiffany L.; Clearfield, Abraham

    2014-01-01

    Using N-(phosphonomethyl) iminodiacetic acid (H4PMIDA), as a complexing agent, two new complexes, (NH4)La(PMIDA)(H2O)•H2O, 1 and (NH4)Yb(PMIDA), 2 have been synthesized hydrothermally. In both compounds, the metal ions are trapped by a three five-membered chelate rings by the chelating PMIDA anions giving a tricapped trigonal prismatic LaO8N and monocapped trigonal prismatic YbO6N geometries for 1 and 2, respectively. The structure of 1 consists of La(PMIDA)(H2O) chelating units, linked together by the phosphonate oxygen atoms O1 and O3 to form a chain along the c-axis. The chains are then connected together by the bridging phosphonate oxygen O2 to form a 2D layered structure with alternating 4- and 8-membered apertures. The structure of 2 consists Yb(PMIDA) chelating units, which are connected by alternating bridging carboxylate and phosphonate groups along the [010] direction forming chains with a corrugated pattern. The third phosphonate oxygen bridges the chains together along the [001] direction to build the two-dimensional layer with 4- and 6-membered apertures in the bc-plane. Under excitation of 330 nm, compound 2 shows a broad emission band at λmax = 460 nm. This emission is essentially in the blue luminescent region, which corresponds to ligand centered fluorescence. PMID:25414845

  5. Surfactant composition containing alkylated biphenylyl phenyl ether sulfonates

    SciTech Connect

    Hinkamp, P. E.

    1984-09-04

    The title compounds are of the formula (R)Y, (((R)X,(M(+)(-)O35-)A-Phenyl)-), (((R)Z, (M (+)(-)O35-)C-Phenyl)-O-)Benzene R is an alkyl radical of at least 6 carbon atoms and each R can be the same or different; M(+) is hydrogen, alkali metal ion, alkaline earth metal ion or ammonium ion radical and each M(+) can be the same or different; a, b and c are individually integers of 0 or 1 with the proviso that the ..sigma..(a+b+c) is equal to 2 or 3; and x, y and z are individually integers of 0-2 with the proviso that ..sigma..(x+y+z)greater than or equal to1. These compounds demonstrate good tolerance to multivalent cations, such as the cations of calcium and magnesium, good resistance to hydrolysis and are useful surfactants in enhanced oil recovery processes.

  6. Charge properties and bacterial contact-killing of hyperbranched polyurea-polyethyleneimine coatings with various degrees of alkylation

    NASA Astrophysics Data System (ADS)

    Roest, Steven; van der Mei, Henny C.; Loontjens, Ton J. A.; Busscher, Henk J.

    2015-11-01

    Coatings of immobilized-quaternary-ammonium-ions (QUAT) uniquely kill adhering bacteria upon contact. QUAT-coatings require a minimal cationic-charge surface density for effective contact-killing of adhering bacteria of around 1014 cm-2. Quaternization of nitrogen is generally achieved through alkylation. Here, we investigate the contribution of additional alkylation with methyl-iodide to the cationic-charge density of hexyl-bromide alkylated, hyperbranched polyurea-polyethyleneimine coatings measuring charge density with fluorescein staining. X-ray-photoelectron-spectroscopy was used to determine the at.% alkylated-nitrogen. Also streaming potentials, water contact-angles and bacterial contact-killing were measured. Cationic-charge density increased with methyl-iodide alkylation times up to 18 h, accompanied by an increase in the at.% alkylated-nitrogen. Zeta-potentials became more negative upon alkylation as a result of shielding of cationiccharges by hydrophobic alkyl-chains. Contact-killing of Gram-positive Staphylococci only occurred when the cationic-charge density exceeded 1016 cm-2 and was carried by alkylated-nitrogen (electron-binding energy 401.3 eV). Gram-negative Escherichia coli was not killed upon contact with the coatings. There with this study reveals that cationic-charge density is neither appropriate nor sufficient to determine the ability of QUAT-coatings to kill adhering bacteria. Alternatively, the at.% of alkylated-nitrogen at 401.3 eV is proposed, as it reflects both cationic-charge and its carrier. The at.% N401.3 eV should be above 0.45 at.% for Gram-positive bacterial contact-killing.

  7. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments.

    PubMed

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4(+)) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4(+) onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20°C to 60°C in order to determine the transport parameters and transformation mechanism of NH4(+) in the studied matrix. The results showed that the adsorption process of NH4(+) onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4(+) onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014cm/h, only a little part of NH4(+) could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20°C to 60°C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  8. Ultra-deep blockade of Na+ channels by a quaternary ammonium ion: catalysis by a transition-intermediate state?

    PubMed Central

    Gingrich, K J; Beardsley, D; Yue, D T

    1993-01-01

    1. Individual Na+ channels from isolated guinea-pig ventricular heart cells were studied using the patch-clamp technique. To localize the selectivity region of the channels we investigated their blockade by a permanently charged quaternary ammonium ion (QX-314, 2-(triethylamino)-N-(2,6-dimethylphenyl)acetamide, 0-5 mM) that was applied to the cytoplasmic side of the channel. 2. Resolution of individual blocking events was enhanced by covalent removal of fast inactivation following brief internal exposure to the enzyme papain. The improved resolution reveals the existence of two distinct modalities of blockade: reduction of unitary current, and millisecond interruptions of current. 3. Both modes of internal block could be potentiated by lowering external Na+ concentration. This finding argues that the two corresponding sites of interaction are both located within the channel pore. 4. Analysis of the voltage dependence of block placed both binding sites deep within the pore, at 70% of the electric field from the cytoplasmic entrance. Combined with recent studies localizing block by external Cd2+, the present results argue that the selectivity region of Na+ channels is quite narrow (spanning about 10% of the electric field), and located near the external side of the channel. 5. The manner in which the two blocking processes interact, along with the physical proximity of their binding sites, leads us to propose that the block configuration responsible for the reduction in unitary current serves as a transition intermediate that catalyses formation of the discrete-block complex. PMID:8120809

  9. Quaternary Ammonium Salts Immobilized on Silica Gel: Exchange Properties and Application as Potentiometric Sensor for Perchlorate Ions.

    PubMed

    de Campos, Elvio A.; da Silva Alfaya, Antonio A.; Ferrari, Rosilene T.; Costa, Creusa Maieru M.

    2001-08-01

    Ammonium chlorides immobilized on silica gel, SA(+)/Cl(-) and SE(+)/Cl(-), were obtained from silica previously modified with 3-aminopropyltriethoxysilane and N-[3-(trimethoxysilyl)-propyl]ethylenediamine, respectively. Both materials showed potential use as an anion exchanger: they are thermically stable (up to 413 K), achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered. The exchange capacities observed for SA(+)/Cl(-) and SE(+)/Cl(-) are 0.70 and 1.19 mmol Cl(-) g(-1), respectively. Through the exchange isotherms and competitive Cl(-)-X(-) exchange (X(-)=F(-), Br(-), I(-), N(3)(-), NO(3)(-), SCN(-), ClO(4)(-)) it was observed that: (i) SE(+)/Cl(-) exchanges the counterion Cl(-) more easily than SA(+)/Cl(-); (ii) SA(+)/Cl(-) presents higher selectivity than SE(+)/Cl(-); and (iii) SA(+)/Cl(-) presents high affinity for ClO(4)(-). Because of these two latter properties presented by the SA(+)/Cl(-), the derivative SA(+)/ClO(4)(-) was used as a potentiometric sensor for this anion, prepared from the supported material on a mixture of graphite powder with epoxy resin. The electrode showed a nernstian behavior and a limit of response of 0.13 mmol L(-1). Potentiometric selectivity coefficients, K(pot)(A, B), were obtained for some interfering anions, and the following interference order was observed: F(-) > SCN(-) > NO(3)(-) > Br(-) > Cl(-) > CH(3)COO(-). The electrode showed fast and stable responses and was useful for approximately 200 measures. Copyright 2001 Academic Press.

  10. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments

    NASA Astrophysics Data System (ADS)

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4+) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4+ onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20 °C to 60 °C in order to determine the transport parameters and transformation mechanism of NH4+ in the studied matrix. The results showed that the adsorption process of NH4+ onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27 cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4+ onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014 cm/h, only a little part of NH4+ could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20 °C to 60 °C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  11. Analysis of Ammonium Nitrate/Urea Nitrate with Crown Ethers and Sugars as Modifiers by Electrospray Ionization-Mass Spectrometry and Ion Mobility Spectrometry.

    PubMed

    Tsai, Chia-Wei; Midey, Anthony; Wu, Ching; Yost, Richard A

    2016-10-04

    Ammonium nitrate (AN) and urea nitrate (UN) are commonly used materials in improvised explosive devices (IEDs). Detection by mass spectrometry (MS) and/or ion mobility spectrometry (IMS) is traditionally difficult. The major challenges of detecting these species arise from their ionic nature and their low mass (for MS detection) and size (for IMS detection). Although AN and UN both produce characteristic higher mass (and size) cluster ions when ionized by electrospray ionization (ESI), detection of AN/UN using cluster ions poses difficulty at trace levels because their formation is concentration-dependent. The addition of modifiers to the ESI process is demonstrated here to overcome some of these challenges for the detection of AN and UN using MS and/or IMS.

  12. In-situ leaching of south Texas uranium ores--part 2: Oxidative removal of adsorbed ammonium ions with sodium hypochlorite

    SciTech Connect

    Paul, J.M.; Fletcher, A.; Johnson, W.F.; Venuto, P.B.

    1983-04-01

    This paper reports a laboratory study of the oxidative destruction by sodium hypochlorite (NaOCl) of ammonium ions adsorbed on relatively reduced south Texas uranium ore. Included are an assessment of reaction stoichiometry, determination of some major reaction pathways and side reactions, and identification of several intermediates. Adsorbed ammonium ions were completely removed by 0.5% NaOCl, with the concentration of NH/sub 3/ in the effluent falling to a very low value after 10 to 15 PV NaOCl oxidant. A small fraction (5 to 10%) of NaOCl was utilized in reacting with NH/sub 3/. After the NH/sub 3/ was nearly depleted, mono-, di-, and trichloramines, the expected intermediates in NaOCl oxidation of NH/sub 3/, were observed. Chloramine decomposition studies showed that all three decomposed completely within 12 days. Since the ore was relatively highly reducing, the major part of the NaOCl was, not unexpectedly, consumed in side reactions. Substantial quantities of sulfate, reflecting oxidation of sulfide minerals such as pyrite, were formed, large amounts of uranium were leached out, and substantial amounts of calcium and magnesium ions were also produced during the presaturation with NH/sub 4/HCO/sub 3/ preceding the oxidation stage.

  13. Indirect atomic absorption spectrometric determination of pindolol, propranolol and levamisole hydrochlorides based on formation of ion-associates with ammonium reineckate and sodium cobaltinitrite.

    PubMed

    Khalil, S; Borham, N

    2000-03-01

    A new simple, accurate, precise and sensitive indirect method for the determination of pindolol HCl (1), propranolol HCl (2) and levamisole HCl (3) using atomic absorption spectrometry has been developed. The method is based on precipitation of the ion-associates formed from the reaction of (1), (2) or (3) with ammonium reineckate and/or sodium cobaltinitrite. The solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. Saturated solutions of each ion-associate were prepared under the optimum conditions and the metal ion content in the supernatant was determined. The method has been used for the determination of 1.14-17.07, 1.18-17.75 and 1.08-16.24 microg/ml of (1), (2) and (3), respectively, using ammonium reineckate, and 1.71-25.60, 1.77-26.62 and 1.62-24.36 microg/ml of (1), (2) and (3), respectively, using sodium cobaltinitrite. The method developed was applied for analysis of bulk drugs and some of their pharmaceutical preparations.

  14. In-situ leaching of south Texas uranium ores--part 2: oxidative removal of adsorbed ammonium ions with sodium hypochlorite

    SciTech Connect

    Paul, J.M.; Fletcher, A.; Johnson, W.F.; Venuto, P.B.

    1983-04-01

    This paper reports a laboratory study of the oxidative destruction by sodium hypochlorite (NaOCl) of ammonium ions adsorbed on relatively reduced south Texas uranium ore. Included are an assessment of reaction stoichiometry, determination of some major reaction pathways and side reactions, and identification of several intermediates. Adsorbed ammonium ions were completely removed by 0.5% NaOCl, with the concentration of NH/sub 3/ in the effluent falling to a very low value after 10 to 15 PV NaOCl oxidant. A small fraction (5 to 10%) of NaOCl was utilized in reacting with NH/sub 3/. After the NH/sub 3/ was nearly depleted, mono-, di-, and trichloramines, the expected intermediates in NaOCl oxidation of NH/sub 3/, were observed. Chloramine decomposition studies showed that all three decomposed completely within 12 days. Since the ore was relatively highly reducing, the major part of the NaOCl was, not unexpectedly, consumed in side reactions. Substantial quantities of sulfate, reflecting oxidation of sulfide minerals such as pyrite, were formed, large amounts of uranium were leached out, and substantial amounts of calcium and magnesium ions were also produced during the presaturation with NH/sub 4/HCO/sub 3/ preceding the oxidation stage.

  15. The ammonium ion in a silicate under compression: infrared spectroscopy and powder X-ray diffraction of NH4AlSi3O8—buddingtonite to 30 GPa

    NASA Astrophysics Data System (ADS)

    E. Vennari, Cara; O'Bannon, Earl F.; Williams, Quentin

    2017-02-01

    The behavior of the ammoniated feldspar buddingtonite, NH4AlSi3O8, has been studied using infrared (IR) spectroscopy up to 30 GPa and using synchrotron powder X-ray diffraction to 10 GPa at room temperature. We examine the bonding of the ammonium ion under pressure and in particular whether hydrogen bonding is enhanced by compaction, as well as probe how the ammonium ion affects the elasticity and behavior of the aluminosilicate framework at pressure. Powder diffraction data yield a bulk modulus of 49 GPa for a pressure derivative of 4, implying that the ammonium ion substitution may induce a modest softening of the feldspar lattice relative to the potassium ion. Under compression, the N-H vibrations are remarkably insensitive to pressure throughout the pressure range of these experiments. However, the vibrations of the aluminosilicate framework of buddingtonite undergo changes in their slope at 13 GPa, implying that a change in compressional mechanism occurs near this pressure, but the vibrational modes of the ammonium molecule show little response to this change. These results show that (1) there is little, if any, enhancement of hydrogen bonding between the ammonium ion and the oxygen ions of the silica and aluminum tetrahedral framework under pressure, as manifested by the slight (and mostly positive) shifts in the N-H stretching vibrations of the ammonium ion; (2) ordering of the ammonium ion is not observed under compression, as no changes in peak width or in the general appearance of the spectra are observed under compression; and (3) structural changes induced by pressure in the aluminosilicate framework do not produce significant changes in the bonding of the ammonium ion. Hence, it appears that the ammonium ion interacts minimally with its surrounding lattice, even at high pressures: Its behavior is compatible with it being, aside from Coulombic attraction to the oxygen-dominated matrix, a largely non-interactive guest molecule within the silicate

  16. Friedel-Crafts Alkylation of Arenes Catalyzed by Ion-Exchange Resin Nanoparticles: An Expedient Synthesis of Triarylmethanes.

    PubMed

    Reddy, B V Subba; Venkateswarlu, A; Sridevi, B; Aldeyab, Salem S; Vinu, Ajayan

    2015-09-01

    Friedel-Crafts alkylation of electron-rich arenes with aldehydes has been achieved in the presence of an active and selective Amberlyst-15 catalyst at the reaction temperature of 60 degrees C in solvent-free conditions. The catalyst exhibits a very high activity and offers the corresponding triarylmethanes in excellent yields with a high selectivity. The use of highly reactive and selective Amberlyist-15 makes this procedure simple, convenient, cost-effective, practical and environmentally friendly. This method provides an easy access to triarylmethanes in a single step using a readily available acidic ionic resin, which is a stable and easy to separate from the reaction mixture by a simple filtration technique.

  17. Main-chain supramolecular polymers based on orthogonal benzo-21-crown-7/secondary ammonium salt and terpyridine/metal ion recognition motifs.

    PubMed

    Tian, Yu-Kui; Wang, Feng

    2014-02-01

    Orthogonal self-assembly of multiple components represents an efficient strategy to afford hierarchical and multifunctional assemblies. Here, we demonstrate the orthogonal recognition behaviors between benzo-21-crown-7/secondary ammonium salt and terpyridine/metal ions (Fe(2+) or Zn(2+) ) recognition motifs. Main-chain supramolecular polymers are subsequently achieved via "one-pot" mixing of the three monomers together (heteroditopic monomer 1, homoditopic secondary ammonium salt monomer 2, and Fe(BF4 )2 •6H2 O or Zn(OTf)2 ), which are confirmed by (1) H NMR, UV-Vis, DOSY, and viscosity measurements. Moreover, different metal ions (Fe(2+) or Zn(2+) ) exert considerable effects on the size of the resulting supramolecular polymers. Integration of two different types of non-covalent interactions renders dynamic and responsive properties for the resulting supramolecular polymers, as triggered by a variety of external stimuli such as temperature, potassium cation, as well as stronger chelating ligands. Therefore, the current work is a prerequisite for the future application of such orthogonal assemblies as intelligent supramolecular materials.

  18. Automated, colorimetric methods for determination of nitrate plus nitrite, nitrite, ammonium and orthophosphate ions in natural water samples

    USGS Publications Warehouse

    Antweiler, Ronald C.; Patton, Charles J.; Taylor, Howard E.

    1996-01-01

    The apparatus and methods used for the automatic, colorimetric determinations of dissolved nutrients (nitrate plus nitrite, nitrite, ammonium and orthophosphate) in natural waters are described. These techniques allow for the determination of nitrate plus nitrite for the concentration range 0.02 to 8 mg/L (milligrams per liter) as N (nitrogen); for nitrite, the range is 0.002 to 1.0 mg/L as N; for ammonium, the range is 0.006 to 2.0 mg/L as N; and for orthophosphate, the range is 0.002 to 1.0 mg/L as P (phosphorus). Data are presented that demonstrate the accuracy, precision and quality control of the methods.

  19. Calcium- and ammonium ion-modification of zeolite amendments affects the metal-uptake of Hieracium piloselloides in a dose-dependent way.

    PubMed

    Peter, Anca; Mihaly-Cozmuta, Leonard; Mihaly-Cozmuta, Anca; Nicula, Camelia; Indrea, Emil; Tutu, Hlanganani

    2012-10-26

    The role of natural zeolite and of two types of modified zeolite (with ammonium and with calcium ions) in reducing the accumulation of ions of heavy metals in roots and leaves of Hieracium piloselloides grown on tailing ponds was investigated. The variation of the content of zeolite (5% w/w and 10% w/w) is another parameter that significantly and positively affects the accumulation of the metal ions in Hieracium piloselloides. The results showed that zeolite used as an amendment in the soil in tailing ponds significantly reduces the accumulation of heavy metal ions in Hieracium piloselloides. The highest concentrations of heavy metals were accumulated in plants grown on soil without zeolite, being followed by the plants grown on the substrate with natural zeolite. Moreover, the translocation factors of heavy metal ions uptake in roots and leaves grown on substrates with modified zeolites are lower than those calculated for the organs grown on the substrate amended with natural zeolite. This behaviour has demonstrated the positive effect of those changes of zeolite amendments in the potential phytoremediation practice.

  20. TREATMENT OF AMMONIUM NITRATE SOLUTIONS

    DOEpatents

    Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

    1958-06-10

    The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

  1. Preparation of porous yttrium oxide microparticles by gelation of ammonium alginate in aqueous solution containing yttrium ions.

    PubMed

    Kawashita, Masakazu; Matsui, Naoko; Li, Zhixia; Miyazaki, Toshiki

    2010-06-01

    Porous Y2O3 microparticles 500 microm in size were obtained, when 1 wt%-ammonium alginate aqueous solution was dropped into 0.5 M-YCl3 aqueous solution by a Pasteur pipette and the resultant gel microparticles were heat-treated at 1100 degrees C. Small pores less than 1 microm were formed in the microparticles by the heat treatment. The bulk density of the heat-treated microparticle was as low as 0.66 g cm(-3). The chemical durability of the heat-treated microparticles in simulated body fluid at pH = 6 and 7 was high enough for clinical application of in situ radiotherapy. Although the size of the microparticles should be decreased to around 25 microm using atomizing device such as spray gun for clinical application, we found that the porous Y2O3 microparticles with high chemical durability and low density can be obtained by utilizing gelation of ammonium alginate in YCl3 aqueous solution in this study.

  2. Reactions and Thermochemistry of Alkyl Ions, Cn H2n+1 + (n=1-8), in the Gas Phase

    DTIC Science & Technology

    2007-11-02

    Calcote and Gill48 have recently completed a comp eats and entropies of ionic specie r reliable predictive models for rehensive compilation of the...pp 1755. (3) Calcote, H. F.; Gill, R . J. Comparison of the Ionic Mechanism of Soot Formation with a Free Radical Mechanism; Bockhorn, H., Ed...A. Gas Phase Ion-Molecule Reaction Rate Constants Through 1986; Maruzen Company, Ltd.: Tokyo, 1987. (7) Arnold, S. T.; Viggiano, A. A.; Morris, R . A

  3. Ammonium methacrylate

    Integrated Risk Information System (IRIS)

    Ammonium methacrylate ; CASRN 16325 - 47 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  4. Ammonium sulfamate

    Integrated Risk Information System (IRIS)

    Ammonium sulfamate ; CASRN 7773 - 06 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  5. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  6. Stabilization of different conformers of bis(trifluoromethanesulfonyl)imide anion in ammonium-based ionic liquids at low temperatures.

    PubMed

    Vitucci, F M; Trequattrini, F; Palumbo, O; Brubach, J-B; Roy, P; Navarra, M A; Panero, S; Paolone, A

    2014-09-25

    The infrared absorption spectra of two ionic liquids with bis(trifluoromethanesulfonyl)imide (TFSI) as an anion and ammonium with different alkyl chains as cations are reported as a function of temperature. Using the comparison with ab initio calculations of the infrared-active intramolecular vibrations, the experimental lines were ascribed to the various ions composing the ionic liquids. In the liquid state of the samples, both conformers of the TFSI ion are present. In the solid state, however, the two conformers survive in N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI), while only cis-TFSI is retained in N-trimethyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide (TMHA-TFSI). We suggest that the longer alkyl chains of the former compound stabilize the less stable conformer of TFSI by means of stronger interactions between anions and cations.

  7. Closed-state inactivation involving an internal gate in Kv4.1 channels modulates pore blockade by intracellular quaternary ammonium ions.

    PubMed

    Fineberg, Jeffrey D; Szanto, Tibor G; Panyi, Gyorgy; Covarrubias, Manuel

    2016-08-09

    Voltage-gated K(+) (Kv) channel activation depends on interactions between voltage sensors and an intracellular activation gate that controls access to a central pore cavity. Here, we hypothesize that this gate is additionally responsible for closed-state inactivation (CSI) in Kv4.x channels. These Kv channels undergo CSI by a mechanism that is still poorly understood. To test the hypothesis, we deduced the state of the Kv4.1 channel intracellular gate by exploiting the trap-door paradigm of pore blockade by internally applied quaternary ammonium (QA) ions exhibiting slow blocking kinetics and high-affinity for a blocking site. We found that inactivation gating seemingly traps benzyl-tributylammonium (bTBuA) when it enters the central pore cavity in the open state. However, bTBuA fails to block inactivated Kv4.1 channels, suggesting gated access involving an internal gate. In contrast, bTBuA blockade of a Shaker Kv channel that undergoes open-state P/C-type inactivation exhibits fast onset and recovery inconsistent with bTBuA trapping. Furthermore, the inactivated Shaker Kv channel is readily blocked by bTBuA. We conclude that Kv4.1 closed-state inactivation modulates pore blockade by QA ions in a manner that depends on the state of the internal activation gate.

  8. Closed-state inactivation involving an internal gate in Kv4.1 channels modulates pore blockade by intracellular quaternary ammonium ions

    PubMed Central

    Fineberg, Jeffrey D.; Szanto, Tibor G.; Panyi, Gyorgy; Covarrubias, Manuel

    2016-01-01

    Voltage-gated K+ (Kv) channel activation depends on interactions between voltage sensors and an intracellular activation gate that controls access to a central pore cavity. Here, we hypothesize that this gate is additionally responsible for closed-state inactivation (CSI) in Kv4.x channels. These Kv channels undergo CSI by a mechanism that is still poorly understood. To test the hypothesis, we deduced the state of the Kv4.1 channel intracellular gate by exploiting the trap-door paradigm of pore blockade by internally applied quaternary ammonium (QA) ions exhibiting slow blocking kinetics and high-affinity for a blocking site. We found that inactivation gating seemingly traps benzyl-tributylammonium (bTBuA) when it enters the central pore cavity in the open state. However, bTBuA fails to block inactivated Kv4.1 channels, suggesting gated access involving an internal gate. In contrast, bTBuA blockade of a Shaker Kv channel that undergoes open-state P/C-type inactivation exhibits fast onset and recovery inconsistent with bTBuA trapping. Furthermore, the inactivated Shaker Kv channel is readily blocked by bTBuA. We conclude that Kv4.1 closed-state inactivation modulates pore blockade by QA ions in a manner that depends on the state of the internal activation gate. PMID:27502553

  9. Ion distribution in quaternary-ammonium-functionalized aromatic polymers: effects on the ionic clustering and conductivity of anion-exchange membranes.

    PubMed

    Weiber, E Annika; Jannasch, Patric

    2014-09-01

    A series of copoly(arylene ether sulfone)s that have precisely two, three, or four quaternary ammonium (QA) groups clustered directly on single phenylene rings along the backbone are studied as anion-exchange membranes. The copolymers are synthesized by condensation polymerizations that involve either di-, tri-, or tetramethylhydroquinone followed by virtually complete benzylic bromination using N-bromosuccinimide and quaternization with trimethylamine. This synthetic strategy allows excellent control and systematic variation of the local density and distribution of QA groups along the backbone. Small-angle X-ray scattering of these copolymers shows extensive ionic clustering, promoted by an increasing density of QA on the single phenylene rings. At an ion-exchange capacity (IEC) of 2.1 meq g(-1), the water uptake decreases with the increasing local density of QA groups. Moreover, at moderate IECs at 20 °C, the Br(-) conductivity of the densely functionalized copolymers is higher than a corresponding randomly functionalized polymer, despite the significantly higher water uptake of the latter. Thus, the location of multiple cations on single aromatic rings in the polymers facilitates the formation of a distinct percolating hydrophilic phase domain with a high ionic concentration to promote efficient anion transport, despite probable limitations by reduced ion dissociation. These findings imply a viable strategy to improve the performance of alkaline membrane fuel cells.

  10. The multimerization state of retroviral RNA is modulated by ammonium ions and affects HIV-1 full-length cDNA synthesis in vitro.

    PubMed Central

    Weiss, S; Häusl, G; Famulok, M; König, B

    1993-01-01

    Genomic human immunodeficiency virus type 1 (HIV-1) RNA fragments containing the dimer linkage structure (DLS) can be dimerized and multimerized in the presence of NH4+ and in the absence of any other cation and any viral or cellular protein. This effect strongly supports the notion that dimerization and multimerization of genomic RNA occurs via purine-quartet formation in quadruple helical RNA structures. The efficiency of RNA dimerization and multimerization in the presence of ammonium ions is about 400 fold increased as compared to alkali metal ions such as potassium. Dimerized retroviral RNA representing a pseudodiploid genome could account for genetic recombination within the virion and during reverse transcription. Application of a novel South-Northern-Blotting procedure with biotinylated RNA and digoxigenin-labelled cDNA in vitro reveals that efficient human- and bovine tRNA(Lys3) primed full-length cDNA-synthesis only takes place with a predominantly monomerized RNA template. Dimerization and multimerization of the RNA significantly reduces full-length cDNA-synthesis. This suggests that monomerization of the dimerized RNA, effected by deionization in vitro, is essential for efficient retroviral reverse transcription in vivo. Images PMID:8177734

  11. Novel binary deep eutectic electrolytes for rechargeable Li-ion batteries based on mixtures of alkyl sulfonamides and lithium perfluoroalkylsulfonimide salts

    NASA Astrophysics Data System (ADS)

    Geiculescu, O. E.; DesMarteau, D. D.; Creager, S. E.; Haik, O.; Hirshberg, D.; Shilina, Y.; Zinigrad, E.; Levi, M. D.; Aurbach, D.; Halalay, I. C.

    2016-03-01

    Ionic liquids (IL's) were proposed for use in Li-ion batteries (LIBs), in order to mitigate some of the well-known drawbacks of LiPF6/mixed organic carbonates solutions. However, their large cations seriously decrease lithium transference numbers and block lithium insertion sites at electrode-electrolyte interfaces, leading to poor LIB rate performance. Deep eutectic electrolytes (DEEs) (which share some of the advantages of ILs but possess only one cation, Li+), were then proposed, in order to overcome the difficulties associated with ILs. We report herein on the preparation, thermal properties (melting, crystallization, and glass transition temperatures), transport properties (specific conductivity and viscosity) and thermal stability of binary DEEs based on mixtures of lithium bis(trifluoromethane)sulfonimide or lithium bis(fluoro)sulfonimide salts with an alkyl sulfonamide solvent. Promise for LIB applications is demonstrated by chronoamperometry on Al current collectors, and cycling behavior of negative and positive electrodes. Residual current densities of 12 and 45 nA cm-2 were observed at 5 V vs. Li/Li+ on aluminum, 1.5 and 16 nA cm-2 at 4.5 V vs. Li/Li+, respectively for LiFSI and LiTFSI based DEEs. Capacities of 220, 130, and 175 mAh· g-1 were observed at low (C/13 or C/10) rates, respectively for petroleum coke, LiMn1/3Ni1/3Co1/3O2 (a.k.a. NMC 111) and LiAl0.05Co0.15Ni0.8O2 (a.k.a. NCA).

  12. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    NASA Astrophysics Data System (ADS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-02-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  13. Heterogeneous photocatalytic reduction of Cr(VI) in UV-irradiated titania suspensions: Effect of protons, ammonium ions, and other interfacial aspects

    SciTech Connect

    Chenthamarakshan, C.R.; Rajeshwar, K.; Wolfrum, E.J.

    2000-03-21

    Heterogeneous photocatalytic reactions in UV-irradiated TiO{sub 2} suspensions are comprised of two conjugate reaction pathways involving the photogenerated electrons and holes, respectively. The role of the hole reaction pathway in the dynamics of the photocatalytic reduction of Cr(VI) is a major focus of this study. It is shown that proton supply plays a crucial role in this reduction reaction. Thus, the Cr(VI) photoreduction kinetics switch from first order to zero order as the proton concentration is systematically increased in the aqueous suspensions. Ammonium ions are also shown to exert a dramatic accelerating influence on Cr(VI) reduction in media of initial pH6. This new observation is rationalized by considering that these species act as hole scavengers. The consequent improvement in quantum yield combines with the facile proton generation upon NH{sub 4}{sup +} photooxidation, to result in the observed rate enhancement. Other interfacial aspects (i.e. adsorption) are also discussed.

  14. Influence of pH and diluent on the ion-pair solvent extraction of aromatic carboxylic acids using quaternary ammonium salts

    SciTech Connect

    Kawamura, K.; Takahashi, K.; Okuwaki, A.

    2006-07-01

    The influence of pH and diluent on the ion-pair solvent extraction of benzene polycarboxylic acids have been investigated for the separation of the coal oxidation products, which are formed by the treatment with alkaline solutions at high temperatures. Although the extent of the solvent extraction of benzoic acid (1BE) with a quaternary ammonium reagent (tri-n-octylmethylammonium chloride) into chloroform and benzene did not change at a very acidic and alkaline solutions, those of 1,2-benzenedicarboxylic acid (12BE) and trimellitic acid (124BE) somewhat decreased at very low pH and very high pH. The magnitudes of the equilibrium constants (K{sub ex}) of 1BE using a different diluent decreased in the order benzene {gt} carbontetrachloride {gt} 1,2-dichloroethane {gt} cyclohexane {gt} hexane {gt} chloroform {gt} 1-octanol and those of 12BE decreased in the order benzene {gt} cyclohexane {gt} carbontetrachloride {gt} hexane {gt} 1,2-dichloroethane {gt} chloroform. The inspection of the correlation between the values of K{sub ex} and several parameters of the diluent implies that the magnitude of K{sub ex} can be described by using the dielectric constant and the solubility parameter of diluent.

  15. The mechanism of ion exchange and adsorption coexist on medium-low concentration ammonium-nitrogen removal by ion-exchange resin.

    PubMed

    Yunnen, Chen; Xiaoyan, Luo; Changshi, Xiong; Liming, Liang

    2015-01-01

    In this study, the removal of medium-low concentration ammonium-nitrogen ([Formula: see text]) from waters and wastewaters on D113 resin was investigated with respect to pH, initial [Formula: see text] concentration, temperature and contact time. The equilibrium of [Formula: see text] on D113 resin reached in 20-30 min. The process of [Formula: see text] removal by D113 resin fitted Langmuir isotherm well. The pseudo second-order kinetic and intra-particle diffusion models were used to investigate the kinetic data of [Formula: see text] on D113 resin. The desorption solution can be returned to production after pretreatment. The mechanism of removal of [Formula: see text] by D113 resin was coexistence of adsorption and cation exchange. When the dosage of D113 resin was 5 g L(-1), pH 6, contact 30 min at room temperature, initial [Formula: see text] concentration being 116 mg L(-1) in rare earth metallurgical wastewater was reduced to 13 mg L(-1) after adsorption treatment.

  16. Atmospheric pressure chemical ionization of explosives induced by soft X-radiation in ion mobility spectrometry: mass spectrometric investigation of the ionization reactions of drift gasses, dopants and alkyl nitrates.

    PubMed

    Riebe, Daniel; Erler, Alexander; Ritschel, Thomas; Beitz, Toralf; Löhmannsröben, Hans-Gerd; Beil, Andreas; Blaschke, Michael; Ludwig, Thomas

    2016-08-01

    A promising replacement for the radioactive sources commonly encountered in ion mobility spectrometers is a miniaturized, energy-efficient photoionization source that produce the reactant ions via soft X-radiation (2.8 keV). In order to successfully apply the photoionization source, it is imperative to know the spectrum of reactant ions and the subsequent ionization reactions leading to the detection of analytes. To that end, an ionization chamber based on the photoionization source that reproduces the ionization processes in the ion mobility spectrometer and facilitates efficient transfer of the product ions into a mass spectrometer was developed. Photoionization of pure gasses and gas mixtures containing air, N2 , CO2 and N2 O and the dopant CH2 Cl2 is discussed. The main product ions of photoionization are identified and compared with the spectrum of reactant ions formed by radioactive and corona discharge sources on the basis of literature data. The results suggest that photoionization by soft X-radiation in the negative mode is more selective than the other sources. In air, adduct ions of O2(-) with H2 O and CO2 were exclusively detected. Traces of CO2 impact the formation of adduct ions of O2(-) and Cl(-) (upon addition of dopant) and are capable of suppressing them almost completely at high CO2 concentrations. Additionally, the ionization products of four alkyl nitrates (ethylene glycol dinitrate, nitroglycerin, erythritol tetranitrate and pentaerythritol tetranitrate) formed by atmospheric pressure chemical ionization induced by X-ray photoionization in different gasses (air, N2 and N2 O) and dopants (CH2 Cl2 , C2 H5 Br and CH3 I) are investigated. The experimental studies are complemented by density functional theory calculations of the most important adduct ions of the alkyl nitrates (M) used for their spectrometric identification. In addition to the adduct ions [M + NO3 ](-) and [M + Cl](-) , adduct ions such as [M + N2 O2 ](-) , [M

  17. Utilization of steel-making slag for the uptake of ammonium and phosphate ions from aqueous solution.

    PubMed

    Jha, Vinay Kumar; Kameshima, Yoshikazu; Nakajima, Akira; Okada, Kiyoshi

    2008-08-15

    Steel-making slag, a waste by-product of the Steel Industry, constitutes a major disposal problem. In the present study, excellent adsorbent materials for reducing eutrophication in wastewaters have been prepared from this slag. Heated samples of acid-treated slag and mixtures of slag with kaolinite and Al(OH)(3) were examined to determine their uptake capacities for NH(4)(+) and PO(4)(3-) from aqueous solutions. In general, the equilibrium pH of the solution increased in comparison to initial pH with the uptake of target ions, the sample activated slag-Al(OH)(3) showing the smallest change. The highest PO(4)(3-) uptake capacity was obtained with the slag-Al(OH)(3) mixture heated at 900 degrees C whereas the highest uptake of NH(4)(+) was found in the slag-Al(OH)(3) mixture heated at 800 degrees C. The uptake rates for PO(4)(3-) and NH(4)(+) by the slag-Al(OH)(3) mixture heated at 900 degrees C were 2.91 and 0.65 micro mol/(g min), respectively. It was shown that heating slag composites prior to incorporation into wastewater treatment filters resulted in an increased degree of NH(4)(+) and PO(4)(3-) uptake.

  18. Investigations on the metabolism of alkyl polyglucosides and their determination in waste water by means of liquid chromatography-electrospray mass spectrometry.

    PubMed

    Eichhorn, P; Knepper, T P

    1999-08-27

    Alkyl polyglucosides (APGs) were analyzed by reversed-phase liquid chromatography coupled to mass spectrometry with electrospray ionization. Analytes were separated according to the chain length of the alkyl homologues, whereas the separation of isomeric forms of the glucose moiety was achieved partially. Depending on the structure of the glucose ring the alkyl monoglucosides show a distinct affinity in terms of the formation of sodium and ammonium adduct ions. Metabolism of isomer pure alkyl monoglucosides was studied on a testfilter device to gather information about the degradation behavior and to obtain eventually poorly degradable metabolites. In spite of unsuccessful detection of any metabolites such as "polyglucoside alcanoic acids", a degradation pathway was proposed including the cleavage of the glucosidic bond as initial step. In addition, a method for the determination of APGs in municipal waste water effluent was developed using solid-phase extraction on reversed-phase material. Recovery rates were in the range of 66 to 98% for three spiked alkyl monoglucosides and a quantitation limit of 0.2 microg l(-1) was achieved.

  19. Dielectric relaxations in partly deuterated ammonium dichromate

    NASA Astrophysics Data System (ADS)

    Gilchrist, John le G.

    1987-12-01

    Two dielectric relaxations in partly deuterated ammonium dichromate are attributed to reorientations of mixed-isotope ammonium ions. Loss peaks were observed between 20 and 40 K and obey the Arrhenius law with activation energy 1.5 kcal/mol for the stronger relaxation. The dipole moment is of the order of 0.015 D.

  20. Analysis of nine food additives in red wine by ion-suppression reversed-phase high-performance liquid chromatography using trifluoroacetic acid and ammonium acetate as ion-suppressors.

    PubMed

    Zhao, Yong-Gang; Chen, Xiao-Hong; Yao, Shan-Shan; Pan, Sheng-Dong; Li, Xiao-Ping; Jin, Mi-Cong

    2012-01-01

    A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous determination of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in red wine. The effects of ion-suppressors, i.e., trifluoroacetic acid (TFA) and ammonium acetate (AmAc) on retention behavior of nine food additives in RP-HPLC separation were discussed in detail. The relationships between retention factors of solutes and volume percent of ion-suppressors in the mobile-phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, respectively. The results showed that the ion suppressors had not only an ion suppression effect, but also an organic modification effect on the acidic analytes. The baseline separation of nine food additives was completed by a gradient elution with acetonitrile-TFA(0.01%, v/v)-AmAc(2.5 mmol L(-1)) aqueous solution as the mobile phase. The recoveries were between 80.2 - 99.5% for all analytes with RSDs in the range of 1.5 - 8.9%. The linearities were in the range of 0.2 - 100.0 mg L(-1) with determination coefficients (r(2)) higher than 0.9991 for all analytes. The limits of quantification (LOQs) were between 0.53 - 0.99 mg L(-1). The applicability of the proposed method to detect and quantify food additives has been demonstrated in the analysis of 30 real samples.

  1. Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands

    DOEpatents

    Maya, L.

    1981-11-05

    A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.

  2. Probing Molecular Interactions between Ammonium-Based Ionic Liquids and N,N-Dimethylacetamide: A Combined FTIR, DLS, and DFT Study.

    PubMed

    Kumar, Pannuru Kiran; Rani, Anjeeta; Olasunkanmi, Lukman O; Bahadur, Indra; Venkatesu, Pannuru; Ebenso, Eno E

    2016-12-15

    The present study investigates the effects of the alkyl chain length of the cationic head-group of some ammonium-based ionic liquids (ILs) (having the same anion) on the interaction between the ILs and N,N-dimethylacetamide (DMA). The molecular interactions between the studied ILs, tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), and their binary mixtures with DMA were studied using the Fourier transform infrared spectroscopy (FTIR) technique, dynamic light scattering (DLS) experiments, and quantum chemical calculations. It was observed from both experimental FTIR analysis and theoretical studies that the strength of intermolecular interactions, such as hydrogen bonding, ion-ion interactions, and induced dipole interactions, between the ILs and DMA depends on the alkyl chain length of the IL cation head-group. The interaction of DMA with IL is energetically favorable and occurs via direct interactions between the IL anion and the carbonyl oxygen of DMA. The results further revealed that the shorter the alkyl chain length of the cationic head-group of the ILs, the stronger the interaction with the DMA molecule, such that the strength of interactions between the ILs and DMA follows the order TEAH > TPAH > TBAH. This trend can be attributed to the increased self-organized aggregation with increasing alkyl chain length of the IL cation.

  3. Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?

    PubMed

    Inan, H; Beler Baykal, B

    2005-01-01

    Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented.

  4. DNA-directed alkylating ligands as potential antitumor agents: sequence specificity of alkylation by intercalating aniline mustards.

    PubMed

    Prakash, A S; Denny, W A; Gourdie, T A; Valu, K K; Woodgate, P D; Wakelin, L P

    1990-10-23

    The sequence preferences for alkylation of a series of novel parasubstituted aniline mustards linked to the DNA-intercalating chromophore 9-aminoacridine by an alkyl chain of variable length were studied by using procedures analogous to Maxam-Gilbert reactions. The compounds alkylate DNA at both guanine and adenine sites. For mustards linked to the acridine by a short alkyl chain through a para O- or S-link group, 5'-GT sequences are the most preferred sites at which N7-guanine alkylation occurs. For analogues with longer chain lengths, the preference of 5'-GT sequences diminishes in favor of N7-adenine alkylation at the complementary 5'-AC sequence. Magnesium ions are shown to selectively inhibit alkylation at the N7 of adenine (in the major groove) by these compounds but not the alkylation at the N3 of adenine (in the minor groove) by the antitumor antibiotic CC-1065. Effects of chromophore variation were also studied by using aniline mustards linked to quinazoline and sterically hindered tert-butyl-9-aminoacridine chromophores. The results demonstrate that in this series of DNA-directed mustards the noncovalent interactions of the carrier chromophores with DNA significantly modify the sequence selectivity of alkylation by the mustard. Relationships between the DNA alkylation patterns of these compounds and their biological activities are discussed.

  5. Insensitive Ammonium Nitrate.

    DTIC Science & Technology

    is reduced by replacing the ammonium nitrate with a solid solution of potassium nitrate in form III ammonium nitrate wherein the potassium nitrate...constitutes from more than zero to less than 50 weight percent of the solid solution . (Author)

  6. Crystal structure of the heptamolybdate(VI) (paramolybdate) ion, [Mo7O24]6-, in the ammonium and potassium tetrahydrate salts

    USGS Publications Warehouse

    Evans, H.T.; Gatehouse, B.M.; Leverett, P.

    1975-01-01

    The crystal structures of the isomorphous salts MI6 [Mo7O24],4H2O (M = NH4 or K) have been refined by three-dimensional X-ray diffraction methods. Unit cell dimensions of these monoclinic compounds, space group P21/C with Z = 4, are, ammonium salt: a = 8.3934 ?? 0.0008, b = 36.1703 ?? 0.0045, c = 10.4715 ?? 0.0011 A??, ?? = 115.958?? ?? 0.008??; and potassium salt: a = 8.15 ?? 0.02, b = 35.68 ?? 0.1, c = 10.30 ?? 0.02 A??, ?? = 115.2?? ?? 02??. By use of multiple Weissenberg patterns, 8197 intensity data (Mo-K?? radiation) for the ammonium compound and 2178 (Cu-K?? radiation) for the potassium compound were estimated visually and used to test and refine Lindqvist's proposed structure in the space group P21/c. Lindqvist's structure was confirmed and the full matrix least-squares isotropic refinement led to R 0.076 (ammonium) 0.120 (potassium), with direct unambiguous location of the cations and water molecules in the potassium compound.

  7. Synthesis Of Alkyl Hydroperoxides Via Alkylation Of gem-Dihydroperoxides

    PubMed Central

    Kyasa, ShivaKumar; Puffer, Benjamin W.

    2013-01-01

    Two-fold alkylation of 1,1-dihydroperoxides, followed by hydrolysis of the resulting bisperoxyacetals, provides a convenient method for synthesis of primary and secondary alkyl hydroperoxides. PMID:23469994

  8. Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

    PubMed

    Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers.

  9. Electrospray Ionization Tandem Mass Spectrometry of Ammonium Cationized Polyethers

    NASA Astrophysics Data System (ADS)

    Nasioudis, Andreas; Heeren, Ron M. A.; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F.

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers.

  10. Formation of carboxylic acids from alcohols and olefins in zeolite H-ZSM-5 under mild conditions via trapping of alkyl carbenium ions with carbon monoxide: An in situ {sup 13}C solid state NMR study

    SciTech Connect

    Stepanov, A.G.; Luzgin, M.V.; Romannikov, V.N.; Sidelnikov, V.N.; Zamaraev K.I.

    1996-12-01

    Using in situ {sup 13}C solid state MAS NMR (for some reagents in combination with ex situ GC-MS), it is shown that butyl alcohols and olefins (ethene, isobutene, octene-1) undergo carbonylation to form carboxylic acids (the Koch reaction) with high conversion on zeolite H-ZSM-5 at 296-373 K. The reactions proceed without application of pressurized conditions, just upon coadsorption of CO and alcohols or CO, H{sub 2}O, and olefins on zeolite. The observed Koch reaction under mild conditions provides strong evidence for the formation of alkyl carbenium ions from alcohols and olefins on the zeolites as crucial reaction intermediates. Of the family of carbenium ions, CO reacts selectively with tertiary cations to produce tertiary carboxylic acids, unless the carbonylated molecule is too large for more bulky tertiary moieties to be accommodated and carbonylated in the narrow pores of H-ZSM05. Thus, t-BuOH, i-BuOH, and isobutene produce trimethylacetic acid with high selectivity and conversion, while ethene transforms selectively into 2-methyl-2-ethyl butyric acid. Reaction of octene-1 molecules with CO and H{sub 2}O results in acids of the C{sub 8}H{sub 17}COOH and C{sub 16}H{sub 33}COOH families with predominantly linear hydrocarbon chains. The data obtained may open up new possibilities in using solid acids in organic synthesis as carbonylation catalysts under mild conditions i.e., low temperature and normal atmospheric pressure. 55 refs., 8 figs.

  11. Alkali-metal ion coordination in uranyl(VI) poly-peroxo complexes in solution, inorganic analogues to crown-ethers. Part 2. Complex formation in the tetramethyl ammonium-, Li(+)-, Na(+)- and K(+)-uranyl(VI)-peroxide-carbonate systems.

    PubMed

    Zanonato, Pier Luigi; Szabó, Zoltán; Vallet, Valerie; Di Bernardo, Plinio; Grenthe, Ingmar

    2015-10-07

    The constitution and equilibrium constants of ternary uranyl(vi) peroxide carbonate complexes [(UO2)p(O2)q(CO3)r](2(p-q-r)) have been determined at 0 °C in 0.50 M MNO3, M = Li, K, and TMA (tetramethyl ammonium), ionic media using potentiometric and spectrophotometric data; (17)O NMR data were used to determine the number of complexes present. The formation of cyclic oligomers, "[(UO2)(O2)(CO3)]n", n = 4, 5, 6, with different stoichiometries depending on the ionic medium used, suggests that Li(+), Na(+), K(+) and TMA ions act as templates for the formation of uranyl peroxide rings where the uranyl-units are linked by μ-η(2)-η(2) bridged peroxide-ions. The templating effect is due to the coordination of the M(+)-ions to the uranyl oxygen atoms, where the coordination of Li(+) results in the formation of Li[(UO2)(O2)(CO3)]4(7-), Na(+) and K(+) in the formation of Na/K[(UO2)(O2)(CO3)]5(9-) complexes, while the large tetramethyl ammonium ion promotes the formation of two oligomers, TMA[(UO2)(O2)(CO3)]5(9-) and TMA[(UO2)(O2)(CO3)]6(11-). The NMR spectra demonstrate that the coordination of Na(+) in the five- and six-membered oligomers is significantly stronger than that of TMA(+); these observations suggest that the templating effect is similar to the one observed in the synthesis of crown-ethers. The NMR experiments also demonstrate that the exchange between TMA[(UO2)(O2)(CO3)]5(9-) and TMA[(UO2)(O2)(CO3)]6(11-) is slow on the (17)O chemical shift time-scale, while the exchange between TMA[(UO2)(O2)(CO3)]6(11-) and Na[(UO2)(O2)(CO3)]6(11-) is fast. There was no indication of the presence of large clusters of the type identified by Burns and Nyman (M. Nyman and P. C. Burns, Chem. Soc. Rev., 2012, 41, 7314-7367) and possible reasons for this and the implications for the synthesis of large clusters are briefly discussed.

  12. Antibacterial Activity of Alanine-Derived Gemini Quaternary Ammonium Compounds.

    PubMed

    Piecuch, Agata; Obłąk, Ewa; Guz-Regner, Katarzyna

    The antibacterial activity of alanine-derived gemini quaternary ammonium salts (chlorides and bromides) with various spacer and alkyl chain lengths was investigated. The studied compounds exhibited a strong bactericidal effect, especially bromides with 10 and 12 carbon alkyl chains and 3 carbon spacer groups (TMPAL-10 Br and TMPAL-12 Br), with a short contact time. Both salts dislodged biofilms of Pseudomonas aeruginosa and Staphylococcus epidermidis, and were lethal to adherent cells of S. epidermidis. Bromide with 2 carbon spacer groups and 12 carbon alkyl chains (TMEAL-12 Br) effectively reduced microbial adhesion by coating polystyrene and silicone surfaces. The results obtained suggest that, after further studies, gemini QAS might be considered as antimicrobial agents in medicine or industry.

  13. Structural study of ammonium metatungstate

    SciTech Connect

    Christian, Joel B. Whittingham, M. Stanley

    2008-08-15

    Several techniques have been used to study the structure of the Keggin-type polyoxometalate salt ammonium metatungstate (AMT)-(NH{sub 4}){sub 6}[H{sub 2}W{sub 12}O{sub 40}]*nH{sub 2}O, a potential fuel cell catalyst. The dehydrated salt is comprised of a mixture of crystallites of different unit cells in a centered eutactic cubic configuration, with an average unit cell of a{approx_equal}12.295. Varied orientations of the Keggin ions in the cubic arrangement create the differences, and orientational variation within each unit cell size represents an energy well. Progressive hydration of each crystallite leads to expansion of the lattice, with the degree of expansion depending on the locations of the water added in relation to the Keggin ion, which is influenced by cation location and hydrogen bonding. The structural hypothesis is supported by electron diffraction of single and multicrystal samples, by powder density measurements, X-ray powder diffraction studies, synchrotron powder X-ray diffraction, and a priori structural modeling studies. Based on the structure, projected active site densities are compared with nanostructured platinum catalysts for fuel cell application. - Graphical abstract: The structure of ammonium metatungstate powders are highly dependent on hydration and POM molecule rotation, with cation and hydrogen bonding forces directing a mixture of structures that have been studied with bulk and single-crystal methods. The illustration shows Monte Carlo simulated anion structural disorder for the fully dehydrated form of the title compound.

  14. Identification of alkylated phosphates by gas chromatography-mass spectrometric investigations with different ionization principles of a thermally aged commercial lithium ion battery electrolyte.

    PubMed

    Weber, Waldemar; Kraft, Vadim; Grützke, Martin; Wagner, Ralf; Winter, Martin; Nowak, Sascha

    2015-05-15

    The thermal aging process of a commercial LiPF6 based lithium ion battery electrolyte has been investigated in view of the formation of volatile phosphorus-containing degradation products. Aging products were analyzed by GC-MS. Structure determination of the products was performed by support of chemical ionization MS in positive and negative modes. A fraction of the discovered compounds belongs to the group of fluorophosphates (phosphorofluoridates) which are in suspect of potential toxicity. This is well known for relative derivatives, e.g. diisopropyl fluorophosphate. Another fraction of the identified compounds belongs to the group of trialkyl phosphates. These compounds may provide a positive impact on the thermal and electrochemical performance of Li-based batteries as repeatedly described in the literature.

  15. Enrichment of perfluorinated alkyl substances on polyethersulfone using 1-methylpyperidine as ion-pair reagent for the clean-up of carrot and amended soil extracts.

    PubMed

    Bizkarguenaga, Ekhiñe; Zabaleta, Itsaso; Iparraguirre, Arantza; Aguirre, Josu; Fernández, Luis Ángel; Berger, Urs; Prieto, Ailette; Zuloaga, Olatz

    2015-10-01

    The development of a simple, cheap and environment friendly analytical method for the simultaneous determination of different perfluoroalkyl substances (PFASs) including seven perfluoroalkyl carboxylic acids, three perfluoroalkane sulfonic acids and perfluorooctanesulfonamide in carrot and amended soil was carried out in the present work. The method was based on focused ultrasound solid-liquid extraction followed by extract clean-up through enrichment of the target compounds on a polymeric material using an ion-pair reagent and detection by liquid chromatography-tandem mass spectrometry. The following variables affecting the clean-up step were evaluated: the nature of the polymeric material (polyethersulfone, PES, versus silicone rod), the amount of the polymeric material (from 1 to 9 mg), the ion-pair reagent (1-methylpyperidine, 1-MP, versus tetrabutylammonium salts), the concentration of the ion-pair reagent (from 5 to 50 mM) and the extraction time (from 15 min to 24 h). Optimum clean-up conditions were obtained using preconcentration on 9 mg of PES polymeric material combined with 5 mM 1-MP as ion-pair reagent for 3h. The method was validated in terms of apparent recoveries in the range of 77-140% and 95-137% at the low concentration (50 ng g(-1)) and in the range of 70-136% and 79-132% at the high concentration (290 ng g(-1)) for amended soil and carrot, respectively, after correction with the corresponding labeled standards. Precision, as relative standard deviation, was within 2-23%, while method detection limits were 0.31-2.85 ng g(-1) for amended soil and 0.11-1.83 ng g(-1) for carrot. In the absence of a certified reference material for the target analytes in the matrices studied, inter-method comparison was carried out and the same samples were processed using two independent clean-up procedures, the one developed in the present work and a classical based on solid-phase extraction. Statistically comparable results were obtained according to the one

  16. Mild ammonium stress increases chlorophyll content in Arabidopsis thaliana.

    PubMed

    Sanchez-Zabala, Joseba; González-Murua, Carmen; Marino, Daniel

    2015-01-01

    Nitrate (NO3(-)) and ammonium (NH4(+)) are the main forms of nitrogen available in the soil for plants. Excessive NH4(+) accumulation in tissues is toxic for plants and exclusive NH4(+)-based nutrition enhances this effect. Ammonium toxicity syndrome commonly includes growth impairment, ion imbalance and chlorosis among others. In this work, we observed high intraspecific variability in chlorophyll content in 47 Arabidopsis thaliana natural accessions grown under 1 mM NH4(+) or 1 mM NO3(-) as N-source. Interestingly, chlorophyll content increased in every accession upon ammonium nutrition. Moreover, this increase was independent of ammonium tolerance capacity. Thus, chlorosis seems to be an exclusive effect of severe ammonium toxicity while mild ammonium stress induces chlorophyll accumulation.

  17. One-pot reductive mono-N-alkylation of aniline and nitroarene derivatives using aldehydes.

    PubMed

    Byun, Eunyoung; Hong, Bomi; De Castro, Kathlia A; Lim, Minkyung; Rhee, Hakjune

    2007-12-07

    One-pot reductive mono-N-alkylation of aniline and nitroarene derivatives using various aldehydes by Pd/C catalyst in aqueous 2-propanol solvent with ammonium formate as in situ hydrogen donor is illustrated. The reaction proceeded smoothly and selectively with excellent yield at room temperature. Our protocol presents a facile, economical, and environmentally benign alternative for reductive amination.

  18. Ammonium nitrate explosive systems

    DOEpatents

    Stinecipher, Mary M.; Coburn, Michael D.

    1981-01-01

    Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

  19. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  20. Ammonium sorption from aqueous solutions by the natural zeolite Transcarpathian clinoptilolite studied under dynamic conditions.

    PubMed

    Sprynskyy, Myroslav; Lebedynets, Mariya; Terzyk, Artur P; Kowalczyk, Piotr; Namieśnik, Jacek; Buszewski, Bogusław

    2005-04-15

    The scope of this study is ammonium-ion uptake from synthetic aqueous solutions onto raw and pretreated forms of the natural zeolite Transcarpathian clinoptilolite under dynamic conditions. Hydrogen ions displaced exchangeable cations on the clinoptilolite in distilled water (sodium ions) and hydrochloric acid (sodium, potassium, and calcium ions) and destroyed the zeolite framework structure in the last case. Ammonium uptake onto the zeolite occurs by exchange with Na(+), Ca(2+), and K(+) ions. Although Na(+) ions were observed to be more easily exchanged for both hydrogen and ammonium ions, the role of Ca(2+) ions increased with zeolite saturation by NH(+)(4) ions. The maximum sorption capacity of the clinoptilolite toward NH(+)(4) ions, estimated under dynamic conditions, is significantly higher than that measured under static conditions; proximity of the values of a distribution coefficient and a retardation factor for different conditions (215-265 dm(3)/kg and 979-1107, respectively) allows us to use these parameters to model ammonium uptake onto the clinoptilolite. Slowing down or interruption in filtration resulted in the improvement of ammonium sorption properties of the zeolite. The ammonium removal improves with use of the finer fractions of the clinoptilolite up to 0.35 mm. A recycling study results confirmed the importance of external diffusion for ammonium sorption by the clinoptilolite. Preliminary treatment of the sorbent confirmed the predominant importance of the ion-exchange mechanism. The advantage of prior NaCl treatment of the clinoptilolite in improvement of ammonium removal over the other techniques was shown.

  1. Exposure to common quaternary ammonium disinfectants decreases fertility in mice

    PubMed Central

    Melin, Vanessa E.; Potineni, Haritha; Hunt, Patricia; Griswold, Jodi; Siems, Bill; Werre, Stephen R.; Hrubec, Terry C.

    2014-01-01

    Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated. Decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing both alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). QACs were detected in caging material over a period of several months following cessation of disinfectant use. Breeding pairs exposed for six months to a QAC disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter and fewer pregnancies. Significant morbidity in near term dams was also observed. In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice. This study illustrates the importance of assessing mixture toxicity of commonly used products whose components have only been evaluated individually. PMID:25483128

  2. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  3. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  4. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  5. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  6. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  7. Determining time-weighted average concentrations of nitrate and ammonium in freshwaters using DGT with ion exchange membrane-based binding layers.

    PubMed

    Huang, Jianyin; Bennett, William W; Welsh, David T; Teasdale, Peter R

    2016-12-08

    Commercially-available AMI-7001 anion exchange and CMI-7000 cation exchange membranes were utilised as binding layers for DGT measurements of NO3-N and NH4-N in freshwaters. These ion exchange membranes are easier to prepare and handle than DGT binding layers consisting of hydrogels cast with ion exchange resins. The membranes showed good uptake and elution efficiencies for both NO3-N and NH4-N. The membrane-based DGTs are suitable for pH 3.5-8.5 and ionic strength ranges (0.0001-0.014 and 0.0003-0.012 mol L(-1) as NaCl for the AMI-7001 and CMI-7000 membrane, respectively) typical of most natural freshwaters. The binding membranes had high intrinsic binding capacities for NO3-N and NH4-N of 911 ± 88 μg and 3512 ± 51 μg, respectively. Interferences from the major competing ions for membrane-based DGTs are similar to DGTs employing resin-based binding layers but with slightly different selectivity. This different selectivity means that the two DGT types can be used in different types of freshwaters. The laboratory and field experiments demonstrated that AMI-DGT and CMI-DGT can be an alternative to A520E-DGT and PrCH-DGT for measuring NO3-N and NH4-N, respectively, as (i) membrane-based DGT have a consistent composition, (ii) avoid the use of toxic chemicals, (iii) provided highly representative results (CDGT : CSOLN between 0.81 and 1.3), and (iv) agreed with resin-based DGTs to within 85-120%.

  8. Antifungal activity of gemini quaternary ammonium salts.

    PubMed

    Obłąk, Ewa; Piecuch, Agata; Krasowska, Anna; Luczyński, Jacek

    2013-12-14

    A series of gemini quaternary ammonium chlorides and bromides with various alkyl chain and spacer lengths was synthesized. The most active compounds against fungi were chlorides with 10 carbon atoms within the hydrophobic chain. Among these compounds were few with no hemolytic activity at minimal inhibitory concentrations. None of the tested compounds were cytotoxic and mutagenic. Cationic gemini surfactants poorly reduced the adhesion of microorganisms to the polystyrene plate, but inhibited the filamentation of Candida albicans. One of the tested compounds eradicated C. albicans and Rodotorula mucilaginosa biofilm, what could be important in overcoming catheter-associated infections. It was also shown that gemini surfactants enhanced the sensitivity of C. albicans to azoles and polyenes, thus they might be potentially used in combined therapy against fungi.

  9. Alkyl and Aromatic Amines as Digestive Ripening/Size Focusing Agents for Gold Nanoparticles

    PubMed Central

    Sun, Yijun; Jose, Deepa; Sorensen, Christopher; Klabunde, Kenneth J.

    2013-01-01

    Both long chain alkyl thiols and alkyl amines behave as size focusing agents for gold nanoparticles, a process that is under thermodynamic control. However, amines do not oxidize surface gold atoms while thiols do oxidize surface gold to gold(I) with evolution of hydrogen gas. Therefore, alkyl amines participate in digestive ripening by a different mechanism. The efficiency of alkyl amines for this process is described and compared, and ultimate gold particle size differences are discussed. Reported herein is a detailed investigation of alkyl chain lengths for alkyl amines, aromatic amines (aniline), and unusually reactive amines (2-phenylethyl amine). Also, two methods of preparation of the crude gold nanoparticles were employed: gold ion reduction/inverse micelle vs. metal vaporization (Solvated Metal Atom Dispersion—SMAD).

  10. Polyimides with pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1982-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  11. Effects of the spaces available for cations in strongly acidic cation-exchange resins on the exchange equilibria by quaternary ammonium ions and on the hydration states of metal ions.

    PubMed

    Watanabe, Yuuya; Ohnaka, Kenji; Fujita, Saki; Kishi, Midori; Yuchi, Akio

    2011-10-01

    The spaces (voids) available for cations in the five exchange resins with varying exchange capacities and cross-linking degrees were estimated, on the basis of the additivity of molar volumes of the constituents. Tetraalkylammonium ions (NR(4)(+); R: Me, Et, Pr) may completely exchange potassium ion on the resin having a larger void radius. In contrast, the ratio of saturated adsorption capacity to exchange capacity of the resin having a smaller void radius decreased with an increase in size of NR(4)(+) ions, due to the interionic contacts. Alkali metal ions could be exchanged quantitatively. While the hydration numbers of K(+), Rb(+), and Cs(+) were independent of the void radius, those of Li(+) and Na(+), especially Na(+), decreased with a decrease in void radius. Interionic contacts between the hydrated ions enhance the dehydration. Multivalent metal ions have the hydration numbers, comparable to or rather greater than those in water. A greater void volume available due to exchange stoichiometry released the interionic contacts and occasionally promoted the involvement of water molecules other than directly bound molecules. The close proximity between ions in the conventional ion-exchange resins having higher exchange capacities may induce varying interactions.

  12. Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

    PubMed

    Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

    2010-05-01

    Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

  13. 70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM NITRATE IN STORAGE. APRIL 18, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  14. Glufosinate-ammonium

    Integrated Risk Information System (IRIS)

    Glufosinate - ammonium ; CASRN 77182 - 82 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  15. Acute ammonium dichromate poisoning.

    PubMed

    Meert, K L; Ellis, J; Aronow, R; Perrin, E

    1994-10-01

    We report the ingestion of ammonium dichromate by a child that resulted in multiple-organ-system failure and death. Exchange transfusion and hemodialysis were ineffective in removing significant amounts of chromium or causing sustained clinical improvement. We suggest that immediate, large doses of the reducing agent ascorbic acid would allow effective reduction of hexavalent chromium with less cellular toxicity.

  16. Physicochemical and tribophysical properties of trioctylalkylammonium bis(salicylato)borate (N888n-BScB) ionic liquids: effect of alkyl chain length.

    PubMed

    Gusain, Rashi; Bakshi, Paramjeet S; Panda, Somenath; Sharma, Om P; Gardas, Ramesh; Khatri, Om P

    2017-03-01

    The alkyl chain length of trioctylalkylammonium bis(salicylato)borates (N888n-BScB; n = 6, 8, 10 and 12) was varied to prepare a series of room-temperature ionic liquids, and then their viscosity and rheological properties were investigated. Besides the omnipresent Coulombic interactions, other interactive forces such as van der Waals interactions, hydrogen bonding, inductive forces, dipole-dipole interactions, etc., collectively determine the physicochemical properties of N888n-BScB ionic liquids. The van der Waals interactions and structural geometry of the ammonium cation (N888n) primarily organized the packing orientation of N888n-BScB ionic liquids and controlled their viscosity and rheological properties as a function of the alkyl chain length. The symmetric cation (N8888) increased the viscosity owing to closer packing driven by van der Waals interactions. The N888n-BScB ionic liquids exhibited non-Newtonian shear thinning behaviour. Furthermore, the decrease in viscosity at higher shear rates indicated that interactive forces in the N888n-BScB ionic liquids were disrupted. These ionic liquids, as lubricants, exhibited significantly lower friction (40-50%) and wear (45-69%) in comparison to PEG 300 synthetic lubricating oil. The degrees of reduction in friction and wear were largely influenced by the chain length of the alkyl group. The N888n-BScB ionic liquids with longer alkyl chains were strongly adsorbed on sliding surfaces and provided better lubrication properties than those with shorter alkyl chains. As a result, the coefficients of friction and wear were decreased by increasing the chain length in N888n-BScB ionic liquids. The tribologically induced adsorption of the BScB anion on metal surfaces, electrostatic interactions between ions, the compact and rigid structure of the BScB anion and van der Waals interactions provided by longer alkyl chains in the N888n cation collectively formed a tribochemical thin film of low shear strength, which resulted

  17. Enantioselective Alkylation of Amino Acid Derivatives Promoted by Cyclic Peptoids under Phase-Transfer Conditions.

    PubMed

    Schettini, Rosaria; De Riccardis, Francesco; Della Sala, Giorgio; Izzo, Irene

    2016-03-18

    The effects of substituents and cavity size on catalytic efficiency of proline-rich cyclopeptoids under phase-transfer conditions were studied. High affinity constants (Ka) for the sodium and potassium cations, comparable to those reported for crown ethers, were observed for an alternated N-benzylglycine/L-proline hexameric cyclopeptoid. This compound was found to catalyze the alkylation of N-(diphenylmethylene)glycine cumyl ester in values of enantioselectivities comparable with those reported for the Cinchona alkaloid ammonium salts derivatives (83-96% ee), and with lower catalyst loading (1-2.5% mol), in the presence of a broad range of benzyl, allyl and alkyl halides.

  18. Quaternary ammonium poly(diethylaminoethyl methacrylate) possessing antimicrobial activity.

    PubMed

    Farah, Shady; Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Beyth, Nurit; Domb, Abraham J

    2015-04-01

    Quaternary ammonium (QA) methacrylate monomers and polymers were synthesized from a N-alkylation of N,N-diethylaminoethyl methacrylate (DEAEM) monomer. Linear copolymers, and for the first time reported crosslinked nanoparticles (NPs), based QA-PDEAEM were prepared by radical polymerization of the quaternized QA-DEAEM monomers with either methyl methacrylate (MMA) or a divinyl monomer. QA-PDEAEM NPs of 50-70 nm were embedded in polyethylene vinyl acetate coating. QA-polymers with N-C8 and N-C18 alkyl chains and copolymers with methyl methacrylate were prepared at different molar ratios and examined for their antimicrobial effectiveness. These coatings exhibited strong antibacterial activity against four representative Gram-positive and Gram-negative bacteria.

  19. Validation of a Rapid and Sensitive UPLC–MS-MS Method Coupled with Protein Precipitation for the Simultaneous Determination of Seven Pyrethroids in 100 µL of Rat Plasma by Using Ammonium Adduct as Precursor Ion

    PubMed Central

    Singh, Sheelendra Pratap; Dwivedi, Nistha; Raju, Kanumuri Siva Rama; Taneja, Isha; Wahajuddin, Mohammad

    2016-01-01

    United States Environmental Protection Agency has recommended estimating pyrethroids’ risk using cumulative exposure. For cumulative risk assessment, it would be useful to have a bioanalytical method for quantification of one or several pyrethroids simultaneously in a small sample volume to support toxicokinetic studies. Therefore, in the present study, a simple, sensitive and high-throughput ultraperformance liquid chromatography–tandem mass spectrometry method was developed and validated for simultaneous analysis of seven pyrethroids (fenvalerate, fenpropathrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, cypermethrin and deltamethrin) in 100 µL of rat plasma. A simple single-step protein precipitation method was used for the extraction of target compounds. The total chromatographic run time of the method was 5 min. The chromatographic system used a Supelco C18 column and isocratic elution with a mobile phase consisting of methanol and 5 mM ammonium formate in the ratio of 90 : 10 (v/v). Mass spectrometer (API 4000) was operated in multiple reaction monitoring positive-ion mode using the electrospray ionization technique. The calibration curves were linear in the range of 7.8–2,000 ng/mL with correlation coefficients of ≥0.99. All validation parameters such as precision, accuracy, recovery, matrix effect and stability met the acceptance criteria according to the regulatory guidelines. The method was successfully applied to the toxicokinetic study of cypermethrin in rats. To the best of our knowledge, this is the first LC–MS-MS method for the simultaneous analysis of pyrethroids in rat plasma. This validated method with minimal modification can also be utilized for forensic and clinical toxicological applications due to its simplicity, sensitivity and rapidity. PMID:26801239

  20. Validation of a Rapid and Sensitive UPLC-MS-MS Method Coupled with Protein Precipitation for the Simultaneous Determination of Seven Pyrethroids in 100 µL of Rat Plasma by Using Ammonium Adduct as Precursor Ion.

    PubMed

    Singh, Sheelendra Pratap; Dwivedi, Nistha; Raju, Kanumuri Siva Rama; Taneja, Isha; Wahajuddin, Mohammad

    2016-04-01

    United States Environmental Protection Agency has recommended estimating pyrethroids' risk using cumulative exposure. For cumulative risk assessment, it would be useful to have a bioanalytical method for quantification of one or several pyrethroids simultaneously in a small sample volume to support toxicokinetic studies. Therefore, in the present study, a simple, sensitive and high-throughput ultraperformance liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous analysis of seven pyrethroids (fenvalerate, fenpropathrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, cypermethrin and deltamethrin) in 100 µL of rat plasma. A simple single-step protein precipitation method was used for the extraction of target compounds. The total chromatographic run time of the method was 5 min. The chromatographic system used a Supelco C18 column and isocratic elution with a mobile phase consisting of methanol and 5 mM ammonium formate in the ratio of 90 : 10 (v/v). Mass spectrometer (API 4000) was operated in multiple reaction monitoring positive-ion mode using the electrospray ionization technique. The calibration curves were linear in the range of 7.8-2,000 ng/mL with correlation coefficients of ≥ 0.99. All validation parameters such as precision, accuracy, recovery, matrix effect and stability met the acceptance criteria according to the regulatory guidelines. The method was successfully applied to the toxicokinetic study of cypermethrin in rats. To the best of our knowledge, this is the first LC-MS-MS method for the simultaneous analysis of pyrethroids in rat plasma. This validated method with minimal modification can also be utilized for forensic and clinical toxicological applications due to its simplicity, sensitivity and rapidity.

  1. Modeling dry and wet deposition of sulfate, nitrate, and ammonium ions in Jiuzhaigou National Nature Reserve, China using a source-oriented CMAQ model: Part II. Emission sector and source region contributions.

    PubMed

    Qiao, Xue; Tang, Ya; Kota, Sri Harsha; Li, Jingyi; Wu, Li; Hu, Jianlin; Zhang, Hongliang; Ying, Qi

    2015-11-01

    A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fields generated by the Weather Research and Forecasting (WRF) model was used to study the dry and wet deposition of nitrate (NO3(-)), sulfate (SO4(2-)), and ammonium (NH4(+)) ions in the Jiuzhaigou National Nature Reserve (JNNR), China from June to August 2010 and to identify the contributions of different emission sectors and source regions that were responsible for the deposition fluxes. Contributions from power plants, industry, transportation, domestic, biogenic, windblown dust, open burning, fertilizer, and manure management sources to deposition fluxes in JNNR watershed and four EANET sites are determined. In JNNR, 96%, 82%, and 87% of the SO4(2-), NO3(-) and NH4(+) deposition fluxes are in the form of wet deposition of the corresponding aerosol species. Industry and power plants are the two major sources of SO4(2-) deposition flux, accounting for 86% of the total wet deposition of SO4(2-), and industry has a higher contribution (56%) than that of power plants (30%). Power plants and industry are also the top sources that are responsible for NO3(-) wet deposition, and contributions from power plants (30%) are generally higher than those from industries (21%). The major sources of NH4(+) wet deposition flux in JNNR are fertilizer (48%) and manure management (39%). Source-region apportionment confirms that SO2 and NOx emissions from local and two nearest counties do not have a significant impact on predicted wet deposition fluxes in JNNR, with contributions less than 10%. While local NH3 emissions account for a higher fraction of the NH4(+) deposition, approximately 70% of NH4(+) wet deposition in JNNR originated from other source regions. This study demonstrates that S and N deposition in JNNR is mostly from long-range transport rather than from local emissions, and to protect JNNR, regional emission reduction controls are needed.

  2. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride

  3. Effects of Ammonium and Non-Ammonium Salt Additions on Methane Oxidation by Methylosinus trichosporium OB3b and Maine Forest Soils.

    PubMed

    King, G M; Schnell, S

    1998-01-01

    Additions of ammonium and non-ammonium salts inhibit atmospheric methane consumption by soil at salt concentrations that do not significantly affect the soil water potential. The response of soils to non-ammonium salts has previously raised questions about the mechanism of ammonium inhibition. Results presented here show that inhibition of methane consumption by non-ammonium salts can be explained in part by ion-exchange reactions: cations desorb ammonium, with the level of desorption varying as a function of both the cation and anion added; differential desorption results in differential inhibition levels. Differences in the extent of inhibition among ammonium salts can also be explained in part by the effects of anions on ammonium exchange. In contrast, only minimal effects of cations and anions are observed in liquid cultures of Methylosinus trichosporium OB3b. The comparable level of inhibition by equinormal concentrations of NH(4)Cl and (NH(4))(2)SO(4) and the insensitivity of salt inhibition to increasing methane concentrations (from 10 to 100 ppm) are of particular interest, since both of these patterns are in contrast to results for soils. The greater inhibition of methane consumption for NH(4)Cl than (NH(4))(2)SO(4) in soils can be attributed to increased ammonium adsorption by sulfate; increasing inhibition by non-ammonium salts with increasing methane concentrations can be attributed to desorbed ammonium and a physiological mechanism proposed previously for pure cultures.

  4. Effects of Ammonium and Non-Ammonium Salt Additions on Methane Oxidation by Methylosinus trichosporium OB3b and Maine Forest Soils†

    PubMed Central

    King, G. M.; Schnell, S.

    1998-01-01

    Additions of ammonium and non-ammonium salts inhibit atmospheric methane consumption by soil at salt concentrations that do not significantly affect the soil water potential. The response of soils to non-ammonium salts has previously raised questions about the mechanism of ammonium inhibition. Results presented here show that inhibition of methane consumption by non-ammonium salts can be explained in part by ion-exchange reactions: cations desorb ammonium, with the level of desorption varying as a function of both the cation and anion added; differential desorption results in differential inhibition levels. Differences in the extent of inhibition among ammonium salts can also be explained in part by the effects of anions on ammonium exchange. In contrast, only minimal effects of cations and anions are observed in liquid cultures of Methylosinus trichosporium OB3b. The comparable level of inhibition by equinormal concentrations of NH4Cl and (NH4)2SO4 and the insensitivity of salt inhibition to increasing methane concentrations (from 10 to 100 ppm) are of particular interest, since both of these patterns are in contrast to results for soils. The greater inhibition of methane consumption for NH4Cl than (NH4)2SO4 in soils can be attributed to increased ammonium adsorption by sulfate; increasing inhibition by non-ammonium salts with increasing methane concentrations can be attributed to desorbed ammonium and a physiological mechanism proposed previously for pure cultures. PMID:16349485

  5. Decomposition of free chlorine with tertiary ammonium.

    PubMed

    Katano, Hajime; Uematsu, Kohei; Tatsumi, Hirosuke; Tsukatani, Toshihide

    2010-01-01

    The reaction of free chlorine with tertiary ammonium or amine compounds in aqueous solution was studied by the amperometry at a rotating Pt-disk electrode. The amperometric method can be applied to follow the concentration of free chlorine (c(Cl)) even in the presence of chloramine species. By addition of mono- and dibutylammonium to the solution containing free chlorine, the step-like decrease in c(Cl) was observed, indicating the rapid formation of the stable chloramine species. By addition of tributylammonium, the c(Cl) was decreased exponentially to nearly zero even if the free chlorine was present initially in excess. The c(Cl)-t curves can be explained by tributylammonium-species-catalyzed decomposition of free chlorine to chloride ion. The catalytic decomposition was observed also with the tertiary-ammonium-based anion-exchange resins. Furthermore, the anion-exchange resins exhibited the decomposition of not only free chlorine but also chloramines in water.

  6. Ammonium chloride poisoning in chronic renal disease

    PubMed Central

    Levene, Donald L.; Knight, Allan

    1974-01-01

    A 58-year-old woman with a long history of renal stone disease and urinary tract infection presented to the emergency room with exhaustion and air hunger. Laboratory data confirmed profound metabolic acidosis. Unduly large quantities of bicarbonate and potassium were required for correction of the deficits. She had been taking 6 g daily of ammonium chloride as a urine-acidifying agent for a period of six months in addition to agents directed against urinary tract infection. The combination of impaired renal function and effective hydrogen ion loading resulted in profound systemic acidosis. The metabolic derangements associated with the administration of ammonium chloride and its use as a therapeutic agent are discussed. PMID:4850503

  7. Regio- and stereoselective 1,2-dihydropyridine alkylation/addition sequence for the synthesis of piperidines with quaternary centers.

    PubMed

    Duttwyler, Simon; Chen, Shuming; Lu, Colin; Mercado, Brandon Q; Bergman, Robert G; Ellman, Jonathan A

    2014-04-07

    The first example of C alkylation of 1,2-dihydropyridines with alkyl triflates and Michael acceptors was developed to introduce quaternary carbon centers with high regio- and diastereoselectivity. Hydride or carbon nucleophile addition to the resultant iminium ion also proceeded with high diastereoselectivity. Carbon nucleophile addition results in an unprecedented level of substitution to provide piperidine rings with adjacent tetrasubstituted carbon atoms.

  8. Ammonium imidazolium dichromate.

    PubMed

    Zhu, Run-Qiang

    2012-04-01

    In the crystal structure of the title compound, (C(3)H(5)N(2))(NH(4))[Cr(2)O(7)], the anions and cations are linked through N-H⋯O hydrogen bonds, resulting in a three-dimensional structure which contains three kinds of layers parallel to (001). One layer contains imidazole cations, the other two layers the ammonium cations and dichromate anions. The dichromate anion has an eclipsed conformation with a dihedral angle of 14.65 (18)° between the mean planes of the O-P-O-P-O backbone.

  9. Hydrothermal synthesis of ammonium illite

    USGS Publications Warehouse

    Sucha, V.; Elsass, F.; Eberl, D.D.; Kuchta, L'.; Madejova, J.; Gates, W.P.; Komadel, P.

    1998-01-01

    Synthetic gel and glass of illitic composition, natural kaolinite, and mixed-layer illite-smectite were used as starting materials for hydrothermal synthesis of ammonium illite. Ammonium illite was prepared from synthetic gel by hydrothermal treatment at 300??C. The onset of crystallization began within 3 h, and well-crystallized ammonium illite appeared at 24 h. Increasing reaction time (up to four weeks) led to many illite layers per crystal. In the presence of equivalent proportions of potassium and ammonium, the gel was transformed to illite with equimolar contents of K and NH4. In contrast, synthesis using glass under the same conditions resulted in a mixture of mixed-layer ammonium illite-smectite with large expandability and discrete illite. Hydrothermal treatments of the fine fractions of natural kaolinite and illite-smectite produced ammonium illite from kaolinite but the illite-smectite remained unchanged.

  10. Removal of ammonium from municipal landfill leachate using natural zeolites.

    PubMed

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-01-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles.

  11. Effective ammonium removal by anaerobic oxidation in microbial fuel cells.

    PubMed

    Jadhav, Dipak A; Ghangrekar, Makarand M

    2015-01-01

    Dual-chamber microbial fuel cells (MFCs), made of clayware cylinder, were operated at different chemical oxygen demands: ammonium-nitrogen (COD:NH4+) ratio (1:1, 10:1 and 5:1) under batch mode for simultaneous removal of ammonia and organic matter from wastewater. Ammonium-N removal efficiencies of 63-32.66% were obtained for COD:NH4+ ratio of 1:10, respectively. Average COD removal efficiencies demonstrated by these MFCs were about 88%; indicating effective use of MFCs for treatment of wastewater containing organic matter and high ammonia concentration. MFCs operated with COD:NH4+ ratio of 10:1 produced highest volumetric power density of 752.88 mW/m3. The ammonium-N removal slightly increased when microbes were exposed to only ammonium as a source of electron when organic source was not supplemented. When this MFC was operated with imposed potential on cathode and without aeration in the cathode chamber, oxidation of ammonium ions at a faster rate confirmed anaerobic oxidation. During the non-turnover condition of cyclic voltammetry, MFC operated with COD:NH4+ ratio of 10:1 gave higher oxidative and reductive currents than MFC operated with COD:NH4+ ratio of 1:1 due to higher redox species. Successful application of such an anammox process for ammonium oxidation in MFCs will be useful for treatment of wastewater containing higher ammonium concentration and harvesting energy in the form of electricity.

  12. Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. Part VI: FT-IR spectra of isomorphously isolated species. NH4+ ions isolated in MKPO 4·6H 2O (M = Mg; Ni) and PO43- ions isolated in MgNH 4AsO 4·6H 2O

    NASA Astrophysics Data System (ADS)

    Cahil, A.; Šoptrajanov, B.; Najdoski, M.; Lutz, H. D.; Engelen, B.; Stefov, V.

    2008-03-01

    Examination of mixed crystals, especially those with isomorphously isolated ions, has proved very useful in spectra-structure correlation studies. Room (RT) and low temperature (LNT) FT-IR spectra of ammonium doped in MgKPO 4·6H 2O and NiKPO 4·6H 2O and phosphate doped in MgNH 4AsO 4·6H 2O in different degrees were recorded. All three compounds are isostructural with struvite, MgNH 4PO 4·6H 2O, space group Pmn2 1, forming substitutional mixed crystals with Cs symmetry of the anions. Analysis of the region of ν 4(NH 4), ν 3(PO 4) and ν 4(PO 4) modes of LNT FT-IR difference spectra of analogues with a small content of NH4+ and PO43- revealed the expected decrease of Td symmetry of free NH4+ and PO43- ions to Cs site symmetry. Due to the Cs site symmetry of the anions, the degeneration of the ν 4(NH 4), ν 3PO 4) and ν 4PO 4) modes is raised and, hence, three components are observed in the difference FT-IR spectra. This conclusion can not be derived only from studies of no-doped polycrystalline samples of struvite type compounds.

  13. 40 CFR 721.6540 - Acrylamide, polymers with tetraalkyl ammonium salt and polyalkyl, aminoalkyl meth-a-cryl-a-mide...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylamide, polymers with tetraalkyl... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6540 Acrylamide, polymers... as acrylamide, polymers with tetraalkyl ammonium salt and poly-al-kyl, amino alkyl...

  14. 40 CFR 721.6540 - Acrylamide, polymers with tetraalkyl ammonium salt and polyalkyl, aminoalkyl meth-a-cryl-a-mide...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acrylamide, polymers with tetraalkyl... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6540 Acrylamide, polymers... as acrylamide, polymers with tetraalkyl ammonium salt and poly-al-kyl, amino alkyl...

  15. 40 CFR 721.6540 - Acrylamide, polymers with tetraalkyl ammonium salt and polyalkyl, aminoalkyl meth-a-cryl-a-mide...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acrylamide, polymers with tetraalkyl... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6540 Acrylamide, polymers... as acrylamide, polymers with tetraalkyl ammonium salt and poly-al-kyl, amino alkyl...

  16. 40 CFR 721.6540 - Acrylamide, polymers with tetraalkyl ammonium salt and polyalkyl, aminoalkyl meth-a-cryl-a-mide...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylamide, polymers with tetraalkyl... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6540 Acrylamide, polymers... as acrylamide, polymers with tetraalkyl ammonium salt and poly-al-kyl, amino alkyl...

  17. 40 CFR 721.6540 - Acrylamide, polymers with tetraalkyl ammonium salt and polyalkyl, aminoalkyl meth-a-cryl-a-mide...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylamide, polymers with tetraalkyl... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6540 Acrylamide, polymers... as acrylamide, polymers with tetraalkyl ammonium salt and poly-al-kyl, amino alkyl...

  18. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium from a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant to and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate, nonsaturated in uranium. The uranium is stripped from, the organic extractant into the stripping solution, and the resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  19. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium for a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate or hydroxide thereby stripping uranium from the organic extractant into the stripping solution. The resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  20. Modeling dry and wet deposition of sulfate, nitrate, and ammonium ions in Jiuzhaigou National Nature Reserve, China using a source-oriented CMAQ model: Part I. Base case model results.

    PubMed

    Qiao, Xue; Tang, Ya; Hu, Jianlin; Zhang, Shuai; Li, Jingyi; Kota, Sri Harsha; Wu, Li; Gao, Huilin; Zhang, Hongliang; Ying, Qi

    2015-11-01

    A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fields generated by the Weather Research and Forecasting (WRF) model was used to study the dry and wet deposition of nitrate (NO3(-)), sulfate (SO4(2-)), and ammonium (NH4(+)) ions in the Jiuzhaigou National Nature Reserve (JNNR), China from June to August 2010 and to identify the contributions of different emission sectors and source regions that were responsible for the deposition fluxes. The model performance is evaluated in this paper and the source contribution analyses are presented in a companion paper. The results show that WRF is capable of reproducing the observed precipitation rates with a Mean Normalized Gross Error (MNGE) of 8.1%. Predicted wet deposition fluxes of SO4(2-) and NO3(-) at the Long Lake (LL) site (3100 m a.s.l.) during the three-month episode are 2.75 and 0.34 kg S(N) ha(-1), which agree well with the observed wet deposition fluxes of 2.42 and 0.39 kg S(N) ha(-1), respectively. Temporal variations in the weekly deposition fluxes at LL are also well predicted. Wet deposition flux of NH4(+) at LL is over-predicted by approximately a factor of 3 (1.60 kg N ha(-1)vs. 0.56 kg N ha(-1)), likely due to missing alkaline earth cations such as Ca(2+) in the current CMAQ simulations. Predicted wet deposition fluxes are also in general agreement with observations at four Acid Deposition Monitoring Network in East Asia (EANET) sites in western China. Predicted dry deposition fluxes of SO4(2-) (including gas deposition of SO2) and NO3(-) (including gas deposition of HNO3) are 0.12 and 0.12 kg S(N) h a(-1) at LL and 0.07 and 0.08 kg S(N) ha(-1) at Jiuzhaigou Bureau (JB) in JNNR, respectively, which are much lower than the corresponding wet deposition fluxes. Dry deposition flux of NH4(+) (including gas deposition of NH3) is 0.21 kg N ha(-1) at LL, and is also much lower than the predicted wet deposition flux. For both dry and wet deposition fluxes, predictions

  1. Outlook for the U. S. alkylation industry

    SciTech Connect

    Felten, J.R.; Bradshaw, T.; McCarthy, K. )

    1994-01-01

    Alkylation has long been recognized in the refining industry as one of the best options to convert refinery olefins into valuable, clean, high octane blending components. In fact, refinery alkylation is a preferred source of blending stocks for reformulated gasoline. However, the hydrofluoric acid (HF) alkylation process and, to a lesser extent, the sulfuric acid (SA) process have come under increasing pressure in the US due to safety and environmental concerns. This paper examines the current outlook for the US alkylation industry including: key trends and driving forces in the industry, the impact of environmental issues on both HF and SA alkylation, US alkylation supply/demand forecast including the outlook for oxygenates, how US refines will respond to the increased demand and restricted supply for alkylates, and the outlook for new solid acid alkylation (SAC) technology.

  2. Total synthesis of alkyl citrate natural products.

    PubMed

    Rizzacasa, Mark A; Sturgess, Dayna

    2014-03-07

    This review highlights the synthesis of members of the alkyl citrate family of natural products. The focus is on the stereoselective construction of the alkyl citrate moiety common to these compounds.

  3. Chichibabin-type direct alkylation of pyridyl alcohols with alkyl lithium reagents.

    PubMed

    Jeffrey, Jenna L; Sarpong, Richmond

    2012-11-02

    Direct C(6) alkylation of pyridyl alcohols can be achieved following an initial deprotonation of the hydroxy group. This transformation, which is believed to occur by a Chichibabin-type alkylation, avoids lateral deprotonation prior to pyridine ring alkylation and gives increased regioselectivity for C(6) over C(4) alkylation.

  4. Refiners discuss HF alkylation process and issues

    SciTech Connect

    Not Available

    1992-04-06

    Safety and oxygenate operations made HF alkylation a hot topic of discussion at the most recent National Petroleum Refiners Association annual question and answer session on refining and petrochemical technology. This paper provides answers to a variety of questions regarding the mechanical, process, and safety aspects of the HF alkylation process. Among the issues discussed were mitigation techniques, removal of oxygenates from alkylation unit feed, and amylene alkylation.

  5. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  6. Toxicity evaluation of selected ammonium-based ionic liquid forms with MCPP and dicamba moieties on Pseudomonas putida.

    PubMed

    Piotrowska, Aleksandra; Syguda, Anna; Wyrwas, Bogdan; Chrzanowski, Łukasz; Heipieper, Hermann J

    2017-01-01

    Combination of the hydrophilic herbicidal anion with hydrophobic, antimicrobial ammonium cation allows to obtain compounds in ionic liquid form with better properties then conventional herbicides. Both cation and anion can be modified by selection of herbicide and the length of alkyl chains in cation structure. However the knowledge of their potential toxic effects are still limited. Furthermore, the relation between hydrophobicity associated with the length of alkyl chains and toxicity for ionic liquids has not been thoroughly studied. Therefore we investigated toxic effects of herbicidal ionic liquid forms on growth inhibition, given as EC50, of the common soil bacterium Pseudomonas putida. We thereby concentrated on quaternary ammonium salts. Analyzed compounds were composed of dicamba or MCPP moieties and cation with various alkyl chain lengths (n = 6,8,10) We compared them with commercial herbicides, and ammonium-based ionic liquids with neutral anion (Br(-)). In addition, cis-trans isomerisation of unsaturated membrane fatty acids in Pseudomonas putida was applied as the proxy for toxicity and membrane activity. We showed that toxicity increased with the length of alkyl chains. However, this correlation is only valid for six and eight carbon atom in alkyl chains, where for n = 10 the EC50 values rise by one order of magnitude. In our studies, the herbicidal ionic liquids [C10,C10,C1,C1N][MCPP] and [C10,C10,C1,C1N][dicamba] showed the lowest toxicity among analyzed quaternary ammonium salts and comparable toxicity with corresponding herbicides. No clear increase in toxicity could be followed by changing the anion moieties for ammonium-based ionic liquid forms.

  7. Substrate specificity of Rhbg: ammonium and methyl ammonium transport

    PubMed Central

    Abdulnour-Nakhoul, Solange M.; Boulpaep, Emile L.; Rabon, Edd; Schmidt, Eric; Hamm, L. Lee

    2010-01-01

    Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pHi) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pHi consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pHi. MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pHi increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pHi in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg. PMID:20592240

  8. Substrate specificity of Rhbg: ammonium and methyl ammonium transport.

    PubMed

    Nakhoul, Nazih L; Abdulnour-Nakhoul, Solange M; Boulpaep, Emile L; Rabon, Edd; Schmidt, Eric; Hamm, L Lee

    2010-09-01

    Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pH(i)) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pH(i) consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pH(i). MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pH(i) increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pH(i) in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg.

  9. The ground water ammonium sorption onto Croatian and Serbian clinoptilolite.

    PubMed

    Siljeg, Mario; Foglar, Lucija; Kukucka, Miroslav

    2010-06-15

    The removal of ammonium from the Valpovo region ground water (VGW) with the use of natural clinoptilolite samples from the Donje Jesenje deposit (Croatia) and the Zlatokop deposit in Vranjska Banja (Serbia) was studied. The natural Serbian (SZ) and Croatian zeolites (CZ) were transformed to the Na-form (Na-CZ and Na-SZ) in order to increase the exchange capacity of zeolite. The CZ and SZ theoretic ammonium sorption capacities were 24.24 mg NH(4)(+)/g CZ and 32.55 mg NH(4)(+)/g SZ, respectively. The application of natural and Na-form of clinoptilolite for efficient removal of ammonium ions from VGW was further investigated. For that purpose, the four "filter guard" vessels filled with zeolite samples were set in parallel in the ground water purification pilot plant. The complete ammonium removal, with the use of SZ and Na-SZ was achieved during 20 h. After having observed saturation of clinoptilolite, the samples were regenerated with the use of 2 mol/L NaCl, and reused for determination of ammonium sorption efficiency. The regenerated samples showed to be still very efficient for NH(4)(+) removal and, in addition, the SZ was shown as superior for ammonium removal in comparison to the CZ.

  10. Biocidal quaternary ammonium resin

    NASA Technical Reports Server (NTRS)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  11. Simultaneous removal of ammonium and suspended solids in multipurpose filters.

    PubMed

    Alkas, Deniz; Baykal, Bilsen Beler; Kinaci, Cumali

    2012-06-01

    A multipurpose filter in which sand and clinoptilolite are used together as filter material is suggested for the simultaneous removal of suspended solids and ammonium in one single unit. The capacity of the clinoptilolite used was determined as 10.4 mg/g for 20 mg/l initial ammonium concentration. In addition, a packed column ion exchanger with clinoptilolite and a classical sand filter were also investigated for comparison. Ammonium and suspended solids removal rates were observed and compared for all columns. The results of the column analysis have revealed that the ammonium removal rate, which was only 20% in the sand column, was increased to 100% by replacing 50% of the sand with clinoptilolite; similarly, the suspended solids removal, which was only 17% in the clinoptilolite column, was increased to 75% by replacing 50% of the clinoptilolite with sand. As such, when ion exchange and filtration processes were carried out in a multipurpose column, high removals for both parameters could be obtained simultaneously. Multipurpose columns could be an alternative both for the upgrading of existing treatment plants or for new plants for simultaneous removal of ammonium and suspended solids, giving considerable savings in terms of land requirements.

  12. Toxicokinetics of ammonium perfluorohexanoate.

    PubMed

    Iwai, Hiroyuki

    2011-10-01

    Excretion patterns and rates of ammonium perfluorohexanoate (APFHx) after administration of a single and multiple (14 days) oral dose(s) at 50 mg/kg to male and female mice and rats were examined. The test substance was [(14)C]-labeled APFHx. After a single oral administration, total excretion was rapid, with mean recoveries of over 90% of the dose at 24 hours after administration, irrespective of gender or species. The major route of elimination was via the urine (means of percentage recovery between 73.0 and 90.2% of the dose), followed by the feces (means of percentage recovery between 7.0 and 15.5% of the dose). Elimination via expired air was negligible. For the multiple dose tests, multiple (13 daily doses) oral administration of APFHx was followed by a single oral administration of [(14)C]-APFHx. Excretion was rapid, with mean recoveries of over 90% of the administered dose (mean values >95% of the ultimately recovered material) at 24 hours after dosing, irrespective of gender or species. The major route of elimination was via the urine (means of percentage recovery between 77.8 and 83.4% of the dose), followed by the feces (means of percentage recovery between 9.6 and 12.9% of the dose).

  13. SYNTHESIS AND INVESTIGATION OF HIGH-MOLECULAR-WEIGHT TERTIARY AMINES AND QUATERNARY AMMONIUM COMPOUNDS FROM COPOLYMERS OF 2-METHYL-5-VINYL-PYRIDINE AND VARIOUS CROSS-LINKING AGENTS

    DTIC Science & Technology

    AMIDES, *COPOLYMERIZATION, *ION EXCHANGE RESINS, *PYRIDINES, ACRYLIC RESINS, ALKYL RADICALS, BENZENE, CHEMICAL PROPERTIES, CHEMICAL REACTIONS ...ETHYLENES, GLYCOLS, METHYL RADICALS, PHYSICAL PROPERTIES, POLYMERIZATION, POLYMERS, SYNTHESIS, VINYL RADICALS.

  14. Determination of anionic surfactants during wastewater recycling process by ion pair chromatography with suppressed conductivity detection

    NASA Technical Reports Server (NTRS)

    Levine, L. H.; Judkins, J. E.; Garland, J. L.; Sager, J. C. (Principal Investigator)

    2000-01-01

    A direct approach utilizing ion pairing reversed-phase chromatography coupled with suppressed conductivity detection was developed to monitor biodegradation of anionic surfactants during wastewater recycling through hydroponic plant growth systems and fixed-film bioreactors. Samples of hydroponic nutrient solution and bioreactor effluent with high concentrations (up to 120 mS electrical conductance) of inorganic ions can be analyzed without pretreatment or interference. The presence of non-ionic surfactants did not significantly affect the analysis. Dynamic linear ranges for tested surfactants [Igepon TC-42, ammonium lauryl sulfate, sodium laureth sulfate and sodium alkyl (C10-C16) ether sulfate] were 2 to approximately 500, 1 to approximately 500, 2.5 to approximately 550 and 3.0 to approximately 630 microg/ml, respectively.

  15. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  16. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOEpatents

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  17. Iron-Catalyzed Decarboxylative Alkyl Etherification of Vinylarenes with Aliphatic Acids as the Alkyl Source.

    PubMed

    Jian, Wujun; Ge, Liang; Jiao, Yihang; Qian, Bo; Bao, Hongli

    2017-03-20

    Because of the lack of effective alkylating reagents, alkyl etherification of olefins with general alkyl groups has not been previously reported. In this work, a variety of alkyl diacyl peroxides and peresters generated from aliphatic acids have been found to enable the first iron-catalyzed alkyl etherification of olefins with general alkyl groups. Primary, secondary and tertiary aliphatic acids are suitable for this reaction, delivering products with yields up to 97 %. Primary and secondary alcohols react well, affording products in up to 91 % yield.

  18. Ammonium and potassium removal for anaerobically digested wastewater using natural clinoptilolite followed by membrane pretreatment.

    PubMed

    Guo, Xuejun; Zeng, Le Larry; Li, Xiaomei; Park, Hung-Suck

    2008-02-28

    On the basis of the wastewater characteristic of anaerobically digested wastewater, this work studied the individual and simultaneous adsorption of ammonium and potassium ions by the natural clinoptilolite. Langmuir, Freundlich, Langmuir-Freundlich, and Toth model were employed to fit the experimental isotherm data and the fitting performances of different models were compared. Both the individual and simultaneous adsorption kinetics of ammonium and potassium were studied at various pHs and temperatures. The individual adsorption of ammonium was very fast and potassium uptake was even faster than that of ammonium. The adsorption approached equilibrium within 1h in most cases. Five models, including pseudo-first-order, pseudo-second-order, Vermeulen's model, squared driving force model and Elovich equation were used to fit the individual and simultaneous adsorption kinetics of ammonium and potassium. The validities of the fittings for the ammonium and potassium adsorption kinetics were also evaluated.

  19. A case of fatal intoxication with ammonium sulfate and a toxicological study using rabbits.

    PubMed

    Sato, A; Gonmori, K; Yoshioka, N

    1999-04-26

    Agricultural fertilizers such as ammonium sulfate are widely used in house gardens as well as in agriculture, but few case reports or toxicological studies of ingested fertilizers have been reported. This paper investigates a fatal case of ammonium sulfate poisoning and demonstrates its clinical and biochemical findings in rabbits. An 85-year-old woman was found dead lying on the ground outside her house in the middle of March, but the autopsy could not determine the cause of her death. Examination at the police laboratory of the solution in the beer can found next to her showed that it was very likely ammonium sulfate. Our measurement showed a significant increase of ammonium and sulfate ions in serum and gastric contents. The cause of her death was determined as poisoning by ammonium sulfate. The total dose of 1500 mg/kg of ammonium sulfate was administered to three rabbits, all of which showed similar symptoms such as mydriasis, irregular respiratory rhythms, local and general convulsions, until they fell into respiratory failure with cardiac arrest. EEG showed slow, suppressive waves and high-amplitude slowing wave pattern, which is generally observed clinically in hyperammonemia in man and animal. There was a remarkable increase in the concentration of ammonium ion and inorganic sulfate ion in serum, and blood gas analysis showed severe metabolic acidosis. These results, mainly findings by EEG, have shown that a rapid increase in ammonium ions in blood can cause damaging the central nervous system without microscopic change. When the cause of death can not be determined, measurement of ammonium ion, inorganic ion and electrolytes in blood as well as in stomach contents at forensic autopsy is necessary.

  20. High performance ammonium nitrate propellant

    NASA Technical Reports Server (NTRS)

    Anderson, F. A. (Inventor)

    1979-01-01

    A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

  1. X-Ray absorption spectroscopy investigation of 1-alkyl-3-methylimidazolium bromide salts

    SciTech Connect

    D'Angelo, Paola; Zitolo, Andrea; Migliorati, Valentina; Bodo, Enrico; Caminiti, Ruggero; Aquilanti, Giuliana; Hazemann, Jean Louis; Testemale, Denis; Mancini, Giordano

    2011-08-21

    X-ray absorption spectroscopy (XAS) has been used to unveil the bromide ion local coordination structure in 1-alkyl-3-methylimidazolium bromide [C{sub n}mim]Br ionic liquids (ILs) with different alkyl chains. The XAS spectrum of 1-ethyl-3-methylimidazolium bromide has been found to be different from those of the other members of the series, from the butyl to the decyl derivatives, that have all identical XAS spectra. This result indicates that starting from 1-buthyl-3-methylimidazolium bromide the local molecular arrangement around the bromide anion is the same independently from the length of the alkyl chain, and that the imidazolium head groups in the liquid ILs with long alkyl chains assume locally the same orientation as in the [C{sub 4}mim]Br crystal. With this study we show that the XAS technique is an effective direct tool for unveiling the local structural arrangements around selected atoms in ILs.

  2. Nearest neighbor affects G:C to A:T transitions induced by alkylating agents

    SciTech Connect

    Glickman, B.W.; Horsfall, M.J.; Gordon, A.J.E.; Burns, P.A.

    1987-12-01

    The influence of local DNA sequence on the distribution of G:C to A:T transitions induced in the lacI gene of E. coli by a series of alkylating agents has been analyzed. In the case of nitrosoguanidine, two nitrosoureas and a nitrosamine, a strong preference for mutation at sites proceeded 5' by a purine base was noted. This preferences was observed with both methyl and ethyl donors where the predicted common ultimate alkylating species in the alkyl diazonium ion. In contrast, this preferences was not seen following treatment with ethylmethanesulfonate. The observed preference for 5'PuG-3' site over 5'-PyG-3' sites corresponds well with alterations observed in the Ha-ras oncogene recovered after treatment with NMU. This indicates that the mutations recovered in the oncogenes are likely the direct consequence of the alkylation treatment and that the local sequence effects seen in E. coli also appear to occur in mammalian cells.

  3. Extrapolating Single Organic Ion Solvation Thermochemistry from Simulated Water Nanodroplets.

    PubMed

    Coles, Jonathan P; Houriez, Céline; Meot-Ner Mautner, Michael; Masella, Michel

    2016-09-08

    We compute the ion/water interaction energies of methylated ammonium cations and alkylated carboxylate anions solvated in large nanodroplets of 10 000 water molecules using 10 ns molecular dynamics simulations and an all-atom polarizable force-field approach. Together with our earlier results concerning the solvation of these organic ions in nanodroplets whose molecular sizes range from 50 to 1000, these new data allow us to discuss the reliability of extrapolating absolute single-ion bulk solvation energies from small ion/water droplets using common power-law functions of cluster size. We show that reliable estimates of these energies can be extrapolated from a small data set comprising the results of three droplets whose sizes are between 100 and 1000 using a basic power-law function of droplet size. This agrees with an earlier conclusion drawn from a model built within the mean spherical framework and paves the road toward a theoretical protocol to systematically compute the solvation energies of complex organic ions.

  4. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  5. Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions.

    PubMed

    Breitenfeld, Jan; Ruiz, Jesus; Wodrich, Matthew D; Hu, Xile

    2013-08-14

    Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the oxidative addition of alkyl halide. The catalysis is second-order in Grignard reagent, first-order in catalyst, and zero-order in alkyl halide. A transient species, [(N2N)Ni-alkyl(2)](alkyl(2)-MgCl), is identified as the key intermediate responsible for the activation of alkyl halide, the formation of which is the turnover-determining step of the catalysis.

  6. Reactions of Tributylstannyl Anioniods with Alkyl Bromides.

    DTIC Science & Technology

    1981-09-28

    g (12 mmol) of cesium tert-butoxide was added to the reaction vessel before the addition of n-butyllithium. Alkylation of Tributylstannyl Anionoids...Dry reaction vessels were purged with argon. The desired alkyl halide (1.0 mmol unless noted) and any desired additive were added to the reaction ...OFFICE OF NAVAL RESEARCH Contract N00014-79-C-0584 Task No. NR 053-714 TECHNICAL REPORT No. 2 Reactions of Tributylstannyl Anionoids with Alkyl

  7. Hygroscopic and phase transition properties of alkyl aminium sulfates at low relative humidities.

    PubMed

    Chu, Yangxi; Sauerwein, Meike; Chan, Chak K

    2015-08-14

    Alkyl aminium sulfates (AASs) can affect the physicochemical properties of atmospheric aerosols such as hygroscopicity. Previous laboratory experiments have shown that the water content in AAS bulk solutions is higher than in aqueous ammonium sulfate solution in the range of 60-95% relative humidity (RH). Furthermore, amine was found to evaporate from the solution during the preparation of AASs from the parent amine and sulfuric acid solutions. Here we report the hygroscopicities of deposited particles of four AASs at different aminium-to-sulfate molar ratios (A/Ss) in the range of <3-90% RH using air-flow cells coupled with in situ micro-Raman spectroscopy. Normalized integrated areas of O-H stretching peaks in the Raman spectra were converted to water-to-solute molar ratios (WSRs) at various RH values. Evaporation of amine was also observed in most cases and the exact A/Ss of sample particles or solutions were determined by ion chromatography. Mono-methylaminium sulfate (MMAS) and mono-ethylaminium sulfate (MEAS) particles were stable at A/S = 2.0, but di-methylaminium sulfate (DMAS) and tri-methylaminium sulfate (TMAS) suffered from DMA and TMA evaporation and eventually equilibrated to the A/S of 1.5 and 1.0, respectively. At these stable compositions MMAS and MEAS exhibited phase transitions in the super-saturation region, while DMAS and TMAS showed a continuous and reversible water uptake. Besides, an approach to estimate the hygroscopicities of DMAS and TMAS particles at an initial A/S larger than that of the stable compositions was presented. In the range of 60-95% RH, the WSRs of all the studied AAS particles were consistent with a previous study based on experimental values and the extended Zdanovskii-Stokes-Robinson equation. In general, all the studied AASs were more hygroscopic than their corresponding ammonium counterparts within the studied RH range and evaporation of amine needs to be corrected in studying unstable AAS particles.

  8. Alkaline phosphatase revisited: hydrolysis of alkyl phosphates.

    PubMed

    O'Brien, Patrick J; Herschlag, Daniel

    2002-03-05

    Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion catalyst with two divalent zinc ions bound approximately 4 A apart in the active site. Studies spanning half a century have elucidated many structural and mechanistic features of this enzyme, rendering it an attractive model for investigating the potent catalytic power of bimetallic centers. Unfortunately, fundamental mechanistic features have been obscured by limitations with the standard assays. These assays generate concentrations of inorganic phosphate (P(i)) in excess of its inhibition constant (K(i) approximately 1 muM). This tight binding by P(i) has affected the majority of published kinetic constants. Furthermore, binding limits k(cat)/K(m) for reaction of p-nitrophenyl phosphate, the most commonly employed substrate. We describe a sensitive (32)P-based assay for hydrolysis of alkyl phosphates that avoids the complication of product inhibition. We have revisited basic mechanistic features of AP with these alkyl phosphate substrates. The results suggest that the chemical step for phosphorylation of the enzyme limits k(cat)/K(m). The pH-rate profile and additional results suggest that the serine nucleophile is active in its anionic form and has a pK(a) of < or = 5.5 in the free enzyme. An inactivating pK(a) of 8.0 is observed for binding of both substrates and inhibitors, and we suggest that this corresponds to ionization of a zinc-coordinated water molecule. Counter to previous suggestions, inorganic phosphate dianion appears to bind to the highly charged AP active site at least as strongly as the trianion. The dependence of k(cat)/K(m) on the pK(a) of the leaving group follows a Brønsted correlation with a slope of beta(lg) = -0.85 +/- 0.1, differing substantially from the previously reported value of -0.2 obtained from data with a less sensitive assay. This steep leaving group dependence is consistent with a largely dissociative transition state for AP-catalyzed hydrolysis of

  9. Ammonium as a sustainable proton shuttle in bioelectrochemical systems.

    PubMed

    Cord-Ruwisch, Ralf; Law, Yingyu; Cheng, Ka Yu

    2011-10-01

    This work examines a pH control method using ammonium (NH(4)(+)) as a sustainable proton shuttle in a CEM-equipped BES. Current generation was sustained by adding NH(3) or ammonium hydroxide (NH(4)OH) to the anolyte, controlling its pH at 7. Ammonium ion migration maintained the catholyte pH at approximately 9.25. Such NH(4)(+)/NH(3) migration accounted for 90±10% of the ionic flux in the BES. Reintroducing the volatilized NH(3) from the cathode into the anolyte maintained a suitable anolyte pH for sustained microbial-driven current generation. Hence, NH(4)(+)/NH(3) acted as a proton shuttle that is not consumed in the process.

  10. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  11. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  12. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  13. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  14. Structures of KcsA in Complex with Symmetrical Quaternary Ammonium Compounds Reveal a Hydrophobic Binding Site

    PubMed Central

    2015-01-01

    Potassium channels allow for the passive movement of potassium ions across the cell membrane and are instrumental in controlling the membrane potential in all cell types. Quaternary ammonium (QA) compounds block potassium channels and have long been used to study the functional and structural properties of these channels. Here we describe the interaction between three symmetrical hydrophobic QAs and the prokaryotic potassium channel KcsA. The structures demonstrate the presence of a hydrophobic pocket between the inner helices of KcsA and provide insight into the binding site and blocking mechanism of hydrophobic QAs. The structures also reveal a structurally hidden pathway between the central cavity and the outside membrane environment reminiscent of the lateral fenestration observed in sodium channels that can be accessed through small conformational changes in the pore wall. We propose that the hydrophobic binding pocket stabilizes the alkyl chains of long-chain QA molecules and may play a key role in hydrophobic drug binding in general. PMID:25093676

  15. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  16. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  17. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  18. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  19. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  20. A maritime pine antimicrobial peptide involved in ammonium nutrition.

    PubMed

    Canales, Javier; Avila, Concepción; Cánovas, Francisco M

    2011-09-01

    A large family of small cysteine-rich antimicrobial peptides (AMPs) is involved in the innate defence of plants against pathogens. Recently, it has been shown that AMPs may also play important roles in plant growth and development. In previous work, we have identified a gene of the AMP β-barrelin family that was differentially regulated in the roots of maritime pine (Pinus pinaster Ait.) in response to changes in ammonium nutrition. Here, we present the molecular characterization of two AMP genes, PpAMP1 and PpAMP2, showing different molecular structure and physicochemical properties. PpAMP1 and PpAMP2 displayed different expression patterns in maritime pine seedlings and adult trees. Furthermore, our expression analyses indicate that PpAMP1 is the major form of AMP in the tree, and its relative abundance is regulated by ammonium availability. In contrast, PpAMP2 is expressed at much lower levels and it is not regulated by ammonium. To gain new insights into the function of PpAMP1, we over-expressed the recombinant protein in Escherichia coli and demonstrated that PpAMP1 strongly inhibited yeast growth, indicating that it exhibits antimicrobial activity. We have also found that PpAMP1 alters ammonium uptake, suggesting that it is involved in the regulation of ammonium ion flux into pine roots.

  1. Analysis of energetic materials by ion chromatography

    SciTech Connect

    Hershey, M.K.

    1985-01-01

    Ion chromatography is a rapid, sensitive, and selective method for ion analysis in a variety of matrices. Ion chromatography was used to determine levels on chloride and chlorate in potassium perchlorate. Comparisons were made with the specific ion electrons method presently being used for these analyses. Also to be discussed are ion chromatographic methods for determining ammonium in boron potassium nitrate, and chloride and ammonium in CP.

  2. Opposite counter-ion effects on condensed bundles of highly charged supramolecular nanotubes in water.

    PubMed

    Wei, Shenghui; Chen, Mingming; Wei, Chengsha; Huang, Ningdong; Li, Liangbin

    2016-07-20

    Although ion specificity in aqueous solutions is well known, its manifestation in unconventional strong electrostatic interactions remains implicit. Herein, the ionic effects in dense packing of highly charged polyelectrolytes are investigated in supramolecular nanotube prototypes. Distinctive behaviors of the orthorhombic arrays composed of supramolecular nanotubes in various aqueous solutions were observed by Small Angle X-ray Scattering (SAXS), depending on the counter-ions' size and affiliation to the surface -COO(-) groups. Bigger tetra-alkyl ammonium (TAA(+)) cations weakly bonding to -COO(-) will compress the orthorhombic arrays, while expansion is induced by smaller alkaline metal (M(+)) ions with strong affiliation to -COO(-). Careful analysis of the changes in the SAXS peaks with different counter/co-ion combinations indicates dissimilar mechanisms underlying the two explicit types of ionic effects. The pH measurements are in line with the ion specificity by SAXS and reveal the strong electrostatic character of the system. It is proposed that the small distances between the charged surfaces, in addition to the selective adsorption of counter-ions by the surface charge, bring out the observed distinctive ionic effects. Our results manifest the diverse mechanisms and critical roles of counter-ion effects in strong electrostatic interactions.

  3. Selective Alkylation of C-Rich Bulge Motifs in Nucleic Acids by Quinone Methide Derivatives.

    PubMed

    Lönnberg, Tuomas; Hutchinson, Mark; Rokita, Steven

    2015-09-07

    A quinone methide precursor featuring a bis-cyclen anchoring moiety has been synthesized and its capacity to alkylate oligonucleotide targets quantified in the presence and absence of divalent metal ions (Zn(2+) , Ni(2+) and Cd(2+) ). The oligonucleotides were designed for testing the sequence and secondary structure specificity of the reaction. Gel electrophoretic analysis revealed predominant alkylation of C-rich bulges, regardless of the presence of divalent metal ions or even the bis-cyclen anchor. This C-selectivity appears to be an intrinsic property of the quinone methide electrophile as reflected by its reaction with an equimolar mixture of the 2'-deoxynucleosides. Only dA-N1 and dC-N3 alkylation products were detected initially and only the dC adduct persisted for detection under conditions of the gel electrophoretic analysis.

  4. Distinct Signaling Pathways and Transcriptome Response Signatures Differentiate Ammonium- and Nitrate-supplied Plants

    PubMed Central

    Patterson, Kurt; Cakmak, Turgay; Cooper, Andrew; Lager, Ida; Rasmusson, Allan G.; Escobar, Matthew A.

    2010-01-01

    Nitrogen is the only macronutrient that is commonly available to plants in both oxidized and reduced forms, mainly nitrate and ammonium. The physiological and molecular effects of nitrate supply have been well studied, but comparatively little is known about ammonium nutrition and its differential effects on cell function and gene expression. We have used a physiologically realistic hydroponic growth system to compare the transcriptomes and redox status of the roots of ammonium- and nitrate-supplied Arabidopsis thaliana plants. While ~60% of nitrogen-regulated genes displayed common responses to both ammonium and nitrate, significant “nitrate-specific” and “ammonium-specific” gene sets were identified. Pathways involved in cytokinin response and reductant generation/distribution were specifically altered by nitrate, while a complex biotic stress response and changes in nodulin gene expression were characteristic of ammonium-supplied plants. Nitrate supply was associated with a rapid decrease in H2O2 production, potentially due to an increased export of reductant from the mitochondrial matrix. The underlying basis of the nitrate- and ammonium-specific patterns of gene expression appears to be different signals elaborated from each nitrogen source, including alterations in extracellular pH that are associated with ammonium uptake, downstream metabolites in the ammonium assimilation pathway, and the presence or absence of the nitrate ion. PMID:20444219

  5. S-alkylation of soft scorpionates.

    PubMed

    Rajasekharan-Nair, Rajeev; Moore, Dean; Chalmers, Kirsten; Wallace, Dawn; Diamond, Louise M; Darby, Lisa; Armstrong, David R; Reglinski, John; Spicer, Mark D

    2013-02-11

    The alkylation reactions of soft scorpionates are reported. The hydrotris(S-alkyl-methimazolyl)borate dications (alkyl = methyl, allyl, benzyl), which were prepared by the reaction of Tm(Me) anion and primary alkyl halides, have been isolated and structurally characterised. The reaction is, however, not universally successful. DFT analysis of these alkylation reactions (C=S versus B-H alkylation) indicates that the observed outcome is driven by kinetic factors. Extending the study to incorporate alternative imine thiones (mercaptobenzothiazole, bz; thiazoline, tz) led to the structural characterisation of di[aquo-μ-aquohydrotris(mercaptobenzothiazolyl)boratosodium], which contains sodium atoms in the κ(3)-S,S,S coordination mode. Alkylation of Na[Tbz] and Na[tzTtz] leads to decomposition resulting in the formation of the simple S-alkylated heterocycles. The analysis of the species involved in these reactions shows an inherent weakness in the B-N bond in soft scorpionates, which has implications for their use in more advanced chemistry.

  6. Occupational asthma due to alkyl cyanoacrylate

    SciTech Connect

    Nakazawa, T. )

    1990-08-01

    A case of bronchial asthma induced by occupational exposure to alkyl cyanoacrylate, an adhesive, occurred in an assembly operation. Provocative exposure testing induced immediate and delayed asthmatic responses. Alkyl cyanoacrylate seemed to act as an allergen or as an irritant, resulting in the development of asthma.

  7. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    PubMed

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry).

  8. Elevated ammonium levels: differential acute effects on three glutamate transporter isoforms.

    PubMed

    Søgaard, Rikke; Novak, Ivana; MacAulay, Nanna

    2012-03-15

    Increased ammonium (NH(4)(+)/NH(3)) in the brain is a significant factor in the pathophysiology of hepatic encephalopathy, which involves altered glutamatergic neurotransmission. In glial cell cultures and brain slices, glutamate uptake either decreases or increases following acute ammonium exposure but the factors responsible for the opposing effects are unknown. Excitatory amino acid transporter isoforms EAAT1, EAAT2, and EAAT3 were expressed in Xenopus oocytes to study effects of ammonium exposure on their individual function. Ammonium increased EAAT1- and EAAT3-mediated [(3)H]glutamate uptake and glutamate transport currents but had no effect on EAAT2. The maximal EAAT3-mediated glutamate transport current was increased but the apparent affinities for glutamate and Na(+) were unaltered. Ammonium did not affect EAAT3-mediated transient currents, indicating that EAAT3 surface expression was not enhanced. The ammonium-induced stimulation of EAAT3 increased with increasing extracellular pH, suggesting that the gaseous form NH(3) mediates the effect. An ammonium-induced intracellular alkalinization was excluded as the cause of the enhanced EAAT3 activity because 1) ammonium acidified the oocyte cytoplasm, 2) intracellular pH buffering with MOPS did not reduce the stimulation, and 3) ammonium enhanced pH-independent cysteine transport. Our data suggest that the ammonium-elicited uptake stimulation is not caused by intracellular alkalinization or changes in the concentrations of cotransported ions but may be due to a direct effect on EAAT1/EAAT3. We predict that EAAT isoform-specific effects of ammonium combined with cell-specific differences in EAAT isoform expression may explain the conflicting reports on ammonium-induced changes in glial glutamate uptake.

  9. Production of poly(alkyl cyanoacrylate)nanoparticles as a coating material that changes wetting property

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alkyl cyanoacrylates have long been used for the synthesis of colloidal nanoparticles. In the involved polymerization reaction, OH- ions derived from dissociation of water have been used as an initiator. In the current research, functional groups on the surface of proteins were utilized as an initia...

  10. DETERMINATION OF ALKYLATED & SULFONATED DIPHENYL OXIDE SULFACTANT BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    EPA Science Inventory

    Methods for the determination of the anionic surfactant Dowfax 8390 are described. Dowfax is a complex mixture of various alkylated and sulfonated diphenyl oxides. The primary component of Dowfax is monoalkylated disulfonated diphenyl oxide (MADS). This work uses ion pairing chro...

  11. Alkyl substituent effects on gas-phase acidities - The influence of hybridization.

    NASA Technical Reports Server (NTRS)

    Brauman, J. I.; Blair, L. K.

    1971-01-01

    Exploration of the effect on acidity of alkyl groups bonded to trigonal and digonal carbon. Some results on the relative acidities of toluene and p-xylene, and acetylene and substitute acetylenes, as determined by ion cyclotron resonance (icr) spectroscopy, are described. Some limitations of the CNDO/2 calculation method are discussed.

  12. Transformation of ammonium dicyanamide into dicyandiamide in the solid.

    PubMed

    Jürgens, Barbara; Höppe, Henning A; Irran, Elisabeth; Schnick, Wolfgang

    2002-09-23

    Ammonium dicyanamide NH(4)[N(CN)(2)] was synthesized through aqueous ion exchange. The crystal structure was investigated by single-crystal X-ray diffraction (P2(1)/c, a = 378.67(6) pm, b = 1240.9(3) pm, c = 911.84(14) pm, beta = 91.488(18) degrees, Z = 4). It derives from the CsCl structure type. Medium strong hydrogen bonds between NH(4)(+) and [N(CN)(2)](-) ions are indicative of the observed formation of dicyandiamide H(4)C(2)N(4) during heating. According to DSC and temperature-dependent X-ray powder diffractometry, this isomerization is exothermic and occurs between 102 and 106 degrees C in the solid. The reaction represents the isolobal analogue to the classical synthesis of urea by heating NH(4)OCN. While other alkali and alkaline earth dicyanamides undergo trimerization or polymerization of their anions during heating, ammonium dicyanamide thus shows a different reactivity.

  13. [Antimicrobial action of ammonium salts of fused heterocycles containing ortho-nitrogen].

    PubMed

    Stankeviciene, Laimute; Grigonis, Aidas; Matusevicius, Algimantas; Janusiene, Laima; Stankevicius, Antanas

    2003-01-01

    By alkylation of hexamethylenetetramine with halogenated derivatives of ketones, ethers, esters or amides of acids, alkyl- and aralkyl halides the corresponding N-monoalkylated compounds of hexamethylenetetramine were obtained. The quaternization of pyridine nitrogen in 5,6-benzoquinoline, 8-hydroxyquinoline, quinoline, 1,10-phenanthroline molecules with alkyl- or aralkylhalides was carried out. The susceptibility of Gram-positive (Streptococcus agalactiae and Staphylococcus aureus) and Gram-negative (E. coli, Salmonella cholerae suis, Salmonella enteridis Gartneri) microorganisms to synthesized quaternary ammonium salts by disc difussion method has been detected. The bacteriostatic action of 0.5-1% solutions of all compounds was assessed in comparison with benzalkonium chloride. It was shown, that the most effectiveness against all strains is possessed by quaternary hexamethylenetetramine ammonium salts, and especially salts, containing 1-propynyl- or hydroxycarbamoylmethyl radicals. The action of these two compounds against Salmonella and Streptococcus was stronger than the action of benzalkonium chloride. Susceptibility of Pseudomonas aeruginosa to these compounds were detected. It was shown, that 1% solutions of chlorides of N-(1-propynyl) hexamethylenetetramonium and N-(hydroxycarbamoylmethyl) hexamethylenetetrammonium demonstrate the same bacteriostatic action against P. aeruginosa as well as benzalkonium chloride.

  14. Benzylic Ammonium Ylide Mediated Epoxidations

    PubMed Central

    Roiser, Lukas; Robiette, Raphaël; Waser, Mario

    2016-01-01

    A high yielding synthesis of stilbene oxides using ammonium ylides has been developed. It turned out that the amine leaving group plays a crucial role as trimethylamine gives higher yields than DABCO or quinuclidine. The amine group also influences the diastereoselectivity, and detailed DFT calculations to understand the key parameters of these reactions have been carried out. PMID:27766017

  15. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  16. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  17. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  18. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  19. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  20. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  1. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  2. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  3. Soft antimicrobial agents: synthesis and activity of labile environmentally friendly long chain quaternary ammonium compounds.

    PubMed

    Thorsteinsson, Thorsteinn; Másson, Már; Kristinsson, Karl G; Hjálmarsdóttir, Martha A; Hilmarsson, Hilmar; Loftsson, Thorsteinn

    2003-09-11

    A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 microg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of <10 microg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 degrees C.

  4. 75 FR 40729 - Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... contact surfaces when applied/used in public eating places, dairy processing equipment, and/ or food... be potentially affected by this action if you are dairy cattle milk producer, food manufacturer, or beverage manufacturer. Potentially affected entities may include, but are not limited to: Dairy cattle...

  5. Induction of contact drematitis in guinea pigs by quaternary ammonium compounds: the mechanisms of antigen formation

    SciTech Connect

    Schallreuter, K.R.; Schulz, K.H.; Wood, J.M.

    1986-12-01

    Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane lipids in forming immunogenic complexes. This surface complexation phenomenon was confirmed by using a spin-labeled quaternary ammonium salt which competed for binding sites to the surface of epidermal cells in vivo. Electron spin resonance was used to demonstrate that stable ion-pairs are formed between binding sites and the two allergenic preservatives. Furthermore, information was obtained on the kinetics of immunogenic complex formation as well as on the position and orientation of the quaternary ammonium ion at the cell surface.

  6. 21 CFR 582.7133 - Ammonium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium alginate. 582.7133 Section 582.7133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ammonium alginate. (a) Product. Ammonium alginate. (b) Conditions of use. This substance is...

  7. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  8. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  9. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  10. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  11. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  12. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  13. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  14. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  15. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  16. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg. No. 7783-20-2)...

  17. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  18. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  19. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  20. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  1. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  2. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  3. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138...

  4. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  5. 76 FR 70366 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... SECURITY Office of the Secretary 6 CFR Part 31 RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY... ``Ammonium Nitrate Security Program,'' which was published in the Federal Register on August 3, 2011. The... 62311). Under the proposed Ammonium Nitrate Security Program, the DHS will regulate the sale...

  6. 76 FR 62311 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ...; ] DEPARTMENT OF HOMELAND SECURITY Office of the Secretary 6 CFR Part 31 RIN 1601-AA52 Ammonium Nitrate Security...), entitled ``Ammonium Nitrate Security Program,'' which was published in the Federal Register on August 3... of ammonium nitrate pursuant to section 563 of the Fiscal Year 2008 Department of Homeland...

  7. 76 FR 11273 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... COMMISSION Ammonium Nitrate From Russia AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the suspended investigation on ammonium nitrate from Russia... investigation on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of...

  8. 76 FR 47238 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... COMMISSION Ammonium Nitrate From Russia Determination On the basis of the record \\1\\ developed in the subject... order on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of material... Commission are contained in USITC Publication 4249 (August 2011), entitled Ammonium Nitrate from...

  9. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... residues of maduramicin ammonium in chickens as follows: (a) A tolerance for maduramicin ammonium (marker residue) in chickens is 0.38 parts per million in fat (target tissue). A tolerance refers to the... animals. (b) The safe concentrations for total maduramicin ammonium residues in uncooked edible...

  10. Regioselectivity of Birch reductive alkylation of biaryls.

    PubMed

    Lebeuf, Raphaël; Robert, Frédéric; Landais, Yannick

    2005-10-13

    [reaction: see text] The regioselectivity of the Birch reductive alkylation of polysubstituted biaryls has been investigated. Results indicate that regioselectivity is affected by the electronic nature of substituents on both aromatic rings. The electron-rich 3,5-dimethoxyphenyl moiety is selectively reduced and then alkylated, while phenols and aniline are not dearomatized under these conditions. Biaryls possessing a phenol moiety are alkylated on the second ring, providing that the acidic proton has been removed prior to the Li/NH3 reduction.

  11. Computational investigation of the hydration of alkyl diammonium cations in water clusters

    NASA Astrophysics Data System (ADS)

    Jahangiri, Soran; Legris-Falardeau, Valéry; Peslherbe, Gilles H.

    2015-02-01

    The hydration behavior of α,ω-alkyl diammonium cations of varying alkyl chain length in water clusters has been investigated with molecular dynamics simulations. The OPLS force field was validated against high-level quantum-chemistry results and experimental data and subsequently used to describe the interatomic interactions in the simulations. The results were further validated with simulations performed with approximate density-functional theory (DFTB3). Surface solvation structures are found to be the most stable, accompanied by considerable ion conformational changes, especially in the case of longer dications. This work demonstrates that, depending on their structure, doubly charged cations may have a high affinity towards aqueous interfaces.

  12. Removal of mercury (II), elemental mercury and arsenic from simulated flue gas by ammonium sulphide.

    PubMed

    Ning, Ping; Guo, Xiaolong; Wang, Xueqian; Wang, Ping; Ma, Yixing; Lan, Yi

    2015-01-01

    A tubular resistance furnace was used as a reactor to simulate mercury and arsenic in smelter flue gases by heating mercury and arsenic compounds. The flue gas containing Hg(2+), Hg(0) and As was treated with ammonium sulphide. The experiment was conducted to investigate the effects of varying the concentration of ammonium sulphide, the pH value of ammonium sulphide, the temperature of ammonium sulphide, the presence of SO2 and the presence of sulphite ion on removal efficiency. The prepared adsorption products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The results showed that the optimal concentration of ammonium sulphide was 0.8 mol/L. The optimal pH value of ammonium sulphide was 10, and the optimal temperature of ammonium sulphide was 20°C.Under the optimum conditions, the removal efficiency of Hg(2+), Hg(0) and As could reach 99%, 88.8%, 98%, respectively. In addition, SO2 and sulphite ion could reduce the removal efficiency of mercury and arsenic from simulated flue gas.

  13. Assessment of the potential for ammonium nitrate formation and reaction in Tank 241-SY-101

    SciTech Connect

    Pederson, L.R.; Bryan, S.A.

    1994-08-01

    Two principal scenarios by which ammonium nitrate may be formed were considered: (a) precipitation of ammonium nitrate in the waste, and (b) ammonium nitrate formation via the gas phase reaction of ammonia and nitrogen dioxide. The first of these can be dismissed because ammonium ions, which are necessary for ammonium nitrate precipitation, can exist only in negligibly small concentrations in strongly alkaline solutions. Gas phase reactions between ammonia, nitrogen dioxide, and water vapor in the gas phase represent the most likely means by which ammonium nitrate aerosols could be formed in Tank 241-SY-101. Predicted ammonium nitrate formation rates are largely controlled by the concentration of nitrogen dioxide. This gas has not been detected among those gases vented from the wastes using Fourier Transform Infrared Spectrometry (FTIR) or mass spectrometry. While detection limits for nitrogen dioxide have not been established experimentally, the maximum concentration of nitrogen dioxide in the gas phase in Tank 241-SY-101 was estimated at 0.1 ppm based on calculations using the HITRAN data base and on FTIR spectra of gases vented from the wastes. At 50 C and with 100 ppm ammonia also present, less than one gram of ammonium nitrate per year is estimated to be formed in the tank. To date, ammonium nitrate has not been detected on HEPA filters in the ventilation system, so any quantity that has been formed in the tank must be quite small, in good agreement with rate calculations. The potential for runaway exothermic reactions involving ammonium nitrate in Tank 241-SY-101 is minimal. Dilution by non-reacting waste components, particularly water, would prevent hazardous exothermic reactions from occurring within the waste slurry, even if ammonium nitrate were present. 41 refs.

  14. Quantitative remote sensing of ammonium minerals, Cedar Mountains, Esmeralda County, Nevada

    NASA Technical Reports Server (NTRS)

    Baugh, William M.; Kruse, Fred A.

    1995-01-01

    Mineral-bound ammonium (NH4+) was discovered by the U.S. Geological Survey in the southern Cedar Mountains of Esmeralda County, Nevada in 1989. At 10 km in length, this site is 100 times larger than any previously known occurrence in volcanic rocks. The ammonium occurs in two hydrothermally altered, crystal-rich rhyolitic tuff units of Oligocene age, and is both structurally and stratigraphically controlled. This research uses Advanced Visible/Infrared Imaging Spectrometer (AVIRIS) data to quantitatively map the mineral-bound ammonium (buddingtonite) concentration in the altered volcanic rocks. Naturally occurring mineral-bound ammonium is fairly rare; however, it has been found to occur in gold-bearing hydrothermal deposits. Because of this association, it is thought that ammonium may be a useful too in exploration for gold and other metal deposits. Mineral-bound ammonium is produced when an ammonium ion (NH4+) replaces the alkali cation site (usually K+) in the crystal structure of silicate minerals such as feldspars, micas and clays. Buddingtonite is an ammonium feldspar. The ammonium originates in buried organic plant matter and is transported to the host rock by hydrothermal fluids. Ammonium alteration does not produce visible changes in the rock, and it is barely detectable with standard x-ray diffraction methods. It is clearly identified, however, by absorption features in short wave-infrared (SWIR) wavelengths (2.0 - 2.5 micrometers). The ammonium absorption features are believed to be caused by N-H vibrational modes and are analogous to hydroxyl (O-H) vibrational modes, only shifted slightly in wavelength. Buddingtonite absorption features in the near- and SWIR lie at 1.56, 2.02 and 2.12 micrometers. The feature at 2.12 micrometer is the strongest of the three and is the only one used in this study. The southern Cedar Mountains are sparsely vegetated and are an ideal site for a remote sensing study.

  15. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  16. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  17. Ruthenium-catalyzed meta/ortho-selective C-H alkylation of azoarenes using alkyl bromides.

    PubMed

    Li, Gang; Ma, Xingxing; Jia, Chunqi; Han, Qingqing; Wang, Ya; Wang, Junjie; Yu, Liuyang; Yang, Suling

    2017-01-19

    meta/ortho-Selective CAr-H (di)alkylation reactions of azoarenes have been achieved via [Ru(p-cymene)Cl2]2 catalyzed ortho-metalation using various types of alkyl bromides. Particularly, dual meta-alkylation of azoarene and reduction offer an attractive strategy for the synthesis of meta-alkylanilines, which are difficult to access via traditional aniline functionalization methods.

  18. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  19. N-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed.

  20. Base-Free Photoredox/Nickel Dual-Catalytic Cross-Coupling of Ammonium Alkylsilicates

    PubMed Central

    2015-01-01

    Single-electron transmetalation is recognized as an enabling technology for the mild transfer of alkyl groups to transition metal catalysts in cross-coupling reactions. Hypercoordinate silicates represent a new and improved class of radical precursors because of their low oxidation potentials and the innocuous byproducts generated upon oxidation. Herein, we report the cross-coupling of secondary and primary ammonium alkylsilicates with (hetero)aryl bromides in good to excellent yields. The base-free conditions have exceptional protic group tolerance on both partners, permitting the cross-coupling of unprotected primary and secondary amines. PMID:26704168

  1. Pseudo-hydroxide extraction in the separation of sodium hydroxide from aqueous solutions using alkyl phenols

    SciTech Connect

    Kang, Hyun Ah; Moyer, Bruce A

    2006-01-01

    Pseudo-hydroxide extraction of sodium hydroxide from aqueous solution using four alkyl phenols of nearly identical molecular weight in 1-octanol at 25 degrees C was examined to understand the effect of alkyl substituents. The order of extraction strength among the four alkyl phenols tested was 4-tert-octylphenol. 3,5-di-tertbutylphenol. 2,4-di-tert-butylphenol. 2,6-di-tert-butyl-4-methylphenol. A good correlation with phenol pK(a) was observed, indicating that extraction strength is determined by phenol acidity, as modified by steric effects in proximity to the phenol - OH group. The effective partition ratios (P-eff) of two phenols from 1 M NaOH solution were determined, showing that the phenols remain predominantly in the 1-octanol phase even when converted to their sodium salts. However, the hydrophobicity of the tested phenols may not be sufficient for process purposes. The equilibrium constants for the governing extraction equilibria were determined by modeling the data using the program SXLSQI, supporting the cation-exchange extraction mechanism. The proposed mechanism consists of two simple sets of equilibria for a. Ion-pair extraction to give Na+OH- ion pairs and corresponding free ions in 1-octanol the phase and b. Cation exchange by monomeric phenol molecules (HAs) to form monomeric organic-phase Na(+)A(-) ion pairs and corresponding free organic-phase ions.

  2. Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives

    DOE PAGES

    Barnhill, William C.; Luo, Huimin; Meyer, III, Harry M; ...

    2016-06-23

    In this work we investigated the feasibility of five quaternary (aprotic) and four tertiary (protic) ammonium ionic liquids (ILs) with an identical organophosphate anion as lubricant antiwear additives. Viscosity, oil solubility, thermal stability, and corrosivity of the candidate ILs were characterized and correlated to the molecular structure. The protic group exhibits higher oil solubility than the aprotic group, and longer alkyl chains seem to provide better oil solubility and higher thermal stability. Selected ILs were applied as oil additives in steel-cast iron tribological tests and demonstrated promising anti-scuffing and anti-wear functionality. The thickness, nanostructure, coverage and composition of the tribofilmmore » formed by the besting performing IL were revealed by surface characterization for mechanistic understanding of the tribochemical interactions between the IL and metal surface. Results provide fundamental insights of the correlations among the molecular structure, physiochemical properties and lubricating performance for ammonium-phosphate ILs.« less

  3. Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives

    SciTech Connect

    Barnhill, William C.; Luo, Huimin; Meyer, III, Harry M; Ma, Cheng; Chi, Miaofang; Papke, Brian L.; Qu, Jun

    2016-06-23

    In this work we investigated the feasibility of five quaternary (aprotic) and four tertiary (protic) ammonium ionic liquids (ILs) with an identical organophosphate anion as lubricant antiwear additives. Viscosity, oil solubility, thermal stability, and corrosivity of the candidate ILs were characterized and correlated to the molecular structure. The protic group exhibits higher oil solubility than the aprotic group, and longer alkyl chains seem to provide better oil solubility and higher thermal stability. Selected ILs were applied as oil additives in steel-cast iron tribological tests and demonstrated promising anti-scuffing and anti-wear functionality. The thickness, nanostructure, coverage and composition of the tribofilm formed by the besting performing IL were revealed by surface characterization for mechanistic understanding of the tribochemical interactions between the IL and metal surface. Results provide fundamental insights of the correlations among the molecular structure, physiochemical properties and lubricating performance for ammonium-phosphate ILs.

  4. Role of tetraalkyl(benzyl)ammonium alkoxides in the catalysis of the alkaline dehydrochlorination reaction

    SciTech Connect

    Shavanov, S.S.; Tolstikov, G.A.; Shutenkova, T.V.; Viktorov, G.A.

    1988-01-10

    The reaction was conducted by the action of aqueous NaOH taken as a 50% solution at a molar ratio to dichloroethane of 2:1 at 50-55 C in the 1% of catalyst on the dichloroethane. The results of the experiments indicated the rising activity of the tetra-alkyl(benzyl) ammonium alkoxides as the lipophilicity of the anion increased, which proceeds in the organic phase. Reaction was effected through a complex formed by the association of quaternary ammonium salts with a hydroxyl-containing compound, the solvation of the associated species with the organochlorine substrate, and coordination with NaOH. The reaction goes in the organic phase and on the interphase surface.

  5. Ligand-Accelerated ortho-C–H Alkylation of Arylcarboxylic Acids Using Alkyl Boron Reagents

    PubMed Central

    Thuy-Boun, Peter S.; Villa, Giorgio; Dang, Devin; Richardson, Paul; Su, Shun; Yu, Jin-Quan

    2013-01-01

    A protocol for the Pd(II)-catalyzed ortho-C–H alkylation of phenylacetic and benzoic acids using alkylboron reagents is disclosed. Mono-protected amino acid ligands (MPAA) were found to significantly promote reactivity. Both potassium alkyltrifluoroborates and alkylboronic acids were compatible coupling partners. The possibility of a radical alkyl transfer to Pd(II) was also investigated. PMID:24124892

  6. Alkylation of isobutane with light olefins: Yields of alkylates for different olefins

    SciTech Connect

    Albright, L.F.; Kranz, K.E.; Masters, K.R.

    1993-12-01

    For alkylation of isobutane with C{sub 3}-C{sub 5} olefins using sulfuric acid as the catalyst, the yields of alkylates with different olefins are compared as the operating conditions are changed. The results of recent pilot plant experiments with propylene, C{sub 4} olefins, and C{sub 5} olefins permit such comparisons. The yields expressed as weight of alkylate produced per 100 wt of olefin consumed varied from about 201:100 to 220:100. Weight ratios of the isobutane consumed per olefin consumed vary from about 101:100 to 120:100. differences of yield values are explained by the changes in the overall chemistry. The procedure employed to calculate yields with good accuracy is based on the analysis of the alkylate and the amount of conjunct polymers produced. Based on literature data, yields are also reported for alkylations using HF as the catalyst.

  7. Palladium-Catalyzed Arylation of Alkyl Sulfenate Anions.

    PubMed

    Jia, Tiezheng; Zhang, Mengnan; Jiang, Hui; Wang, Carol Y; Walsh, Patrick J

    2015-11-04

    A unique palladium-catalyzed arylation of alkyl sulfenate anions is introduced that affords aryl alkyl sulfoxides in high yields. Due to the base sensitivity of the starting sulfoxides, sulfenate anion intermediates, and alkyl aryl sulfoxide products, the use of a mild method to generate alkyl sulfenate anions was crucial to the success of this process. Thus, a fluoride triggered elimination strategy was employed with alkyl 2-(trimethylsilyl)ethyl sulfoxides to liberate the requisite alkyl sulfenate anion intermediates. In the presence of palladium catalysts with bulky monodentate phosphines (SPhos and Cy-CarPhos) and aryl bromides or chlorides, alkyl sulfenate anions were readily arylated. Moreover, the thermal fragmentation and the base promoted elimination of alkyl sulfoxides was overridden. The alkyl sulfenate anion arylation exhibited excellent chemoselectivity in the presence of functional groups, such as anilines and phenols, which are also known to undergo palladium catalyzed arylation reactions.

  8. Effects of alkyl polyglycoside (APG) on composting of agricultural wastes

    SciTech Connect

    Zhang Fabao; Gu Wenjie; Xu Peizhi; Tang Shuanhu; Xie Kaizhi; Huang Xu; Huang Qiaoyi

    2011-06-15

    Composting is the biological degradation and transformation of organic materials under controlled conditions to promote aerobic decomposition. To find effective ways to accelerate composting and improve compost quality, numerous methods including additive addition, inoculation of microorganisms, and the use of biosurfactants have been explored. Studies have shown that biosurfactant addition provides more favorable conditions for microorganism growth, thereby accelerating the composting process. However, biosurfactants have limited applications because they are expensive and their use in composting and microbial fertilizers is prohibited. Meanwhile, alkyl polyglycoside (APG) is considered a 'green' surfactant. This study aims to determine whether APG addition into a compost reaction vessel during 28-day composting can enhance the organic matter degradation and composting process of dairy manure. Samples were periodically taken from different reactor depths at 0, 3, 5, 7, 14, 21, and 28 days. pH levels, electrical conductivity (EC), ammonium and nitrate nitrogen, seed germination indices, and microbial population were determined. Organic matter and total nitrogen were also measured. Compared with the untreated control, the sample with APG exhibited slightly increased microbial populations, such as bacteria, fungi, and actinomycetes. APG addition increased temperatures without substantially affecting compost pH and EC throughout the process. After 28 days, APG addition increased nitrate nitrogen concentrations, promoted matter degradation, and increased seed germination indices. The results of this study suggest that the addition of APG provides more favorable conditions for microorganism growth, slightly enhancing organic matter decomposition and accelerating the composting process, improving the compost quality to a certain extent.

  9. Ammonium removal from aqueous solutions by using natural Chinese (Chende) zeolite as adsorbent.

    PubMed

    Huang, Haiming; Xiao, Xianming; Yan, Bo; Yang, Liping

    2010-03-15

    This paper presents a study of the removal of ammonium ion from aqueous solutions using natural Chinese (Chende) zeolite. A series of experiments was conducted to examine the effects of solution pH, particle size, contact time, adsorbent dosage, and the presence of other cation- and anion species on ammonium removal. The findings indicated that these parameters named had a significant effect on the removal of ammonium by the zeolite. The effect of other cations on the removal of ammonium followed the order of preference Na(+)>K(+)>Ca(2+)>Mg(2+) at identical mass concentrations, and the effect of the presence of individual anions followed the order of preference carbonate>chloride>sulfate>phosphate at identical mass concentrations of ammonium ions. Kinetic analysis showed that the adsorption of ammonium on zeolite at different ranges of particle size well followed the pseudo-second-order model and followed the intra-particle diffusion model only during the initial 60 min of the adsorption process. Equilibrium isotherm data was fitted to the linear Langmuir- and Freundlich models with the latter model providing the better description of the process (R(2)=0.991-0.997) compared to the former (R(2)=0.902-0.989).

  10. Characterization of ammonium retention processes onto cactus leaves fibers using FTIR, EDX and SEM analysis.

    PubMed

    Wahab, Mohamed Ali; Boubakri, Hatem; Jellali, Salah; Jedidi, Naceur

    2012-11-30

    In order to reduce the impact of nitrogen pollution and to increase the agronomic value of plant wastes to be reused as organic fertilizer, we have investigated the removal of ammonium from aqueous solutions onto cactus leave fibers (CLF), and the mechanisms involved in the retention of ammonium at CLF surface. The results showed that ammonium retention onto these fibers occurred for a wide pH (6-10) and temperature ranges (20-60°C) and the biosorption potential of CLF increased with temperature from 1.4 to 2.3 mg g(-1) for initial concentration of 50 mg L(-1). The modeling studies showed that the ammonium biosorption was well described by the pseudo-second-order model, predicting therefore, chemisorption interactions-type at earlier stages and by intraparticle diffusion at later stages. Biosorption is governed by film diffusion process at higher concentrations and by particle diffusion process at higher temperatures. The surface of CLF determined by SEM revealed the presence of cracks and cavities which may allow the intraparticle diffusion and the ion exchange processes. Moreover, FTIR and EDX analysis before and after ammonium retention showed that the main mechanisms involved in the removal of ammonium were the ionic exchange by calcium ions as well as H(+) and the complexation with carboxylic, alcoholic and phenolic groups.

  11. Microbial nitrate-dependent cyclohexane degradation coupled with anaerobic ammonium oxidation.

    PubMed

    Musat, Florin; Wilkes, Heinz; Behrends, Astrid; Woebken, Dagmar; Widdel, Friedrich

    2010-10-01

    An anaerobic nitrate-reducing enrichment culture was established with a cyclic saturated petroleum hydrocarbon, cyclohexane, the fate of which in anoxic environments has been scarcely investigated. GC-MS showed cyclohexylsuccinate as a metabolite, in accordance with an anaerobic enzymatic activation of cyclohexane by carbon-carbon addition to fumarate. Furthermore, long-chain cyclohexyl-substituted cell fatty acids apparently derived from cyclohexane were detected. Nitrate reduction was not only associated with cyclohexane utilization but also with striking depletion of added ammonium ions. Significantly more ammonium was consumed than could be accounted for by assimilation. This indicated the occurrence of anaerobic ammonium oxidation (anammox) with nitrite from cyclohexane-dependent nitrate reduction. Indeed, nitrite depletion was stimulated upon further addition of ammonium. Analysis of 16S rRNA genes and subsequent cell hybridization with specific probes showed that approximately 75% of the bacterial cells affiliated with the Geobacteraceae and approximately 18% with Candidatus 'Brocadia anammoxidans' (member of the Planctomycetales), an anaerobic ammonium oxidizer. These results and additional quantitative growth experiments indicated that the member of the Geobacteraceae reduced nitrate with cyclohexane to nitrite and some ammonium; the latter two and ammonium added to the medium were scavenged by anammox bacteria to yield dinitrogen. A model was established to quantify the partition of each microorganism in the overall process. Such hydrocarbon oxidation by an alleged 'denitrification' ('pseudo-denitrification'), which in reality is a dissimilatory loop through anammox, can in principle also occur in other microbial systems with nitrate-dependent hydrocarbon attenuation.

  12. Paleosols in central Illinois as potential sources of ammonium in groundwater

    USGS Publications Warehouse

    Glessner, J.J.G.; Roy, W.R.

    2009-01-01

    Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. ?? 2009 National Ground Water Association.

  13. High irradiance improves ammonium tolerance in wheat plants by increasing N assimilation.

    PubMed

    Setién, Igor; Fuertes-Mendizabal, Teresa; González, Azucena; Aparicio-Tejo, Pedro Ma; González-Murua, Carmen; González-Moro, María Begoña; Estavillo, José María

    2013-05-15

    Ammonium is a paradoxical nutrient ion. Despite being a common intermediate in plant metabolism whose oxidation state eliminates the need for its reduction in the plant cell, as occurs with nitrate, it can also result in toxicity symptoms. Several authors have reported that carbon enrichment in the root zone enhances the synthesis of carbon skeletons and, accordingly, increases the capacity for ammonium assimilation. In this work, we examined the hypothesis that increasing the photosynthetic photon flux density is a way to increase plant ammonium tolerance. Wheat plants were grown in a hydroponic system with two different N sources (10mM nitrate or 10mM ammonium) and with two different light intensity conditions (300 μmol photon m(-2)s(-1) and 700 μmol photon m(-2)s(-1)). The results show that, with respect to biomass yield, photosynthetic rate, shoot:root ratio and the root N isotopic signature, wheat behaves as a sensitive species to ammonium nutrition at the low light intensity, while at the high intensity, its tolerance is improved. This improvement is a consequence of a higher ammonium assimilation rate, as reflected by the higher amounts of amino acids and protein accumulated mainly in the roots, which was supported by higher tricarboxylic acid cycle activity. Glutamate dehydrogenase was a key root enzyme involved in the tolerance to ammonium, while glutamine synthetase activity was low and might not be enough for its assimilation.

  14. Ion exchange materials, method of forming ion exchange materials, and methods of treating liquids

    DOEpatents

    Wertsching, Alan K.; Peterson, Eric S.; Wey, John E.

    2007-12-25

    The invention includes an ion affinity material having an organic component which is sulfonated and which is chemically bonded to an inorganic substrate component. The invention includes a method of forming a metal binding material. A solid support material comprising surface oxide groups is provided and an organic component having at least one alkyl halide is covalently linked to at least some of the surface oxide groups to form a modified support material. The at least one alkyl halide is subsequently converted into an alkyl sulfonate. The invention further includes a method and system for extracting ions from a liquid. An ion exchange material having a sulfonated alkyl silane component covalently bonded to a metal oxide support material is provided and a liquid is exposed to the ion exchange material.

  15. Phase Diagram of Ammonium Nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-06-01

    Ammonium Nitrate (AN) has often been subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood - resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety, in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN, in different chemical environments, at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 15 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 673 K. The present study has been supported by the U.S. DHS under Award Number 2008-ST-061-ED0001.

  16. Anion exchangers with branched functional ion exchange layers of different hydrophilicity for ion chromatography.

    PubMed

    Shchukina, O I; Zatirakha, A V; Smolenkov, A D; Nesterenko, P N; Shpigun, O A

    2015-08-21

    Novel polystyrene-divinylbenzene (PS-DVB) based anion exchangers differing from each other in the structure of the branched functional ion exchange layer are prepared to investigate the role of linker and functional site on ion exchange selectivity. The proposed method of synthesis includes the obtaining of aminated PS-DVB particles by means of their acylation with following reductive amination with methylamine. Further modification of the obtained secondary aminogroups is provided by the alkylation with either 1,4-butanediol diglycidyl ether (1,4-BDDGE) or resorcinol diglycidyl ether (RDGE), which form the linkers of different hydrophobicity, and amination of terminal epoxide rings with trimethylamine (TMA), dimethylethanolamine (DMEA), methyldiethanolamine (MDEA) or triethanolamine (TEA). The variation of the structure and hydrophobicity of the linker and terminal quaternary ammonium sites in the functional layer allows the alteration of selectivity and separation efficiency of the obtained adsorbents. The ion exchange selectivity and separation efficiency of the anion exchangers are evaluated using the model mixtures of anions (F(-), HCOO(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) in potassium hydroxide eluents. The adsorbents show the decrease of selectivity with increasing the hydrophilicity of the terminal functional site. The anion exchangers having more flexible and hydrophilic 1,4-BDDGE linker provide smaller separation factors for most of the analytes as compared with RDGE-containing adsorbents with the same terminal ion exchange sites, but are characterized with higher column efficiencies and better peak symmetry for polarizable anions. In case of 1,4-BDDGE-modified anion exchangers of the particle size of 3.3μm functionalized with DMEA and MDEA the calculated values of column efficiencies for polarizable NO3(-) and Br(-) are up to 49,000 and 53,000N/m, respectively, which is almost twice higher than the values obtained for the RDGE

  17. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  18. The isobutylene-isobutane alkylation process in liquid HF revisited.

    PubMed

    Esteves, P M; Araújo, C L; Horta, B A C; Alvarez, L J; Zicovich-Wilson, C M; Ramírez-Solís, A

    2005-07-07

    Details on the mechanism of HF catalyzed isobutylene-isobutane alkylation were investigated. On the basis of available experimental data and high-level quantum chemical calculations, a detailed reaction mechanism is proposed taking into account solvation effects of the medium. On the basis of our computational results, we explain why the density of the liquid media and stirring rates are the most important parameters to achieve maximum yield of alkylate, in agreement with experimental findings. The ab initio Car-Parrinello molecular dynamics calculations show that isobutylene is irreversibly protonated in the liquid HF medium at higher densities, leading to the ion pair formation, which is shown to be a minimum on the potential energy surface after optimization using periodic boundary conditions. The HF medium solvates preferentially the fluoride anion, which is found as solvated [FHF](-) or solvated F(-.)(HF)(3). On the other hand, the tert-butyl cation is weakly solvated, where the closest HF molecules appear at a distance of about 2.9 Angstrom with the fluorine termination of an HF chain.

  19. Properties of the Nafion membrane impregnated with hydroxyl ammonium based ionic liquids

    NASA Astrophysics Data System (ADS)

    Garaev, Valeriy; Kleperis, Janis; Pavlovica, Sanita; Vaivars, Guntars

    2012-08-01

    In this work, the Nafion 112 membrane impregnated with nine various hydroxyl ammonium based ionic liquids have been investigated. The used ionic liquids were combined from hydroxyl ammonium cations (2-hydroxyethylammonium/HEA, bis(2- hydroxyethyl)ammonium/BHEA, tris(2-hydroxyethyl)ammonium/THEA) and carboxylate anions (formate, acetate, lactate). The membranes are characterized by conductivity and thermal stability measurements. It was found, that almost all composites have 10 times higher ion conductivity than a pure Nafion 112 at 90 °C in ambient environment due to the higher thermal stability. The thermal stability of Nafion membrane was increased by all studied nine ionic liquids. In this work, only biodegradable ionic liquids were used for composite preparation.

  20. Treatment of ammonium-rich swine waste in modified porphyritic andesite fixed-bed anaerobic bioreactor.

    PubMed

    Wang, Qinghong; Yang, Yingnan; Li, Dawei; Feng, Chuanping; Zhang, Zhenya

    2012-05-01

    In this study, a modified porphyritic andesite (WRS) was developed as ammonium adsorbent and bed material for the anaerobic digestion of ammonium-rich swine waste. The performance in bioreactors with modified WRS, natural WRS, calcium chloride and no additives was investigated. The bioreactor with modified WRS exhibited the best performance, with start-up time on the 7th day, methane yield of 359.71 ml/g-VS, and COD removal of 67.99% during all 44 days of the experiment at 35°C. The effective ammonium adsorption and essential ions dissociation for microorganisms by modified WRS, as well as the immobilization of microbial on the surface of the modified WRS play a great role on the high efficiency anaerobic digestion of ammonium-rich swine waste.

  1. Salting out of proteins using ammonium sulfate precipitation.

    PubMed

    Duong-Ly, Krisna C; Gabelli, Sandra B

    2014-01-01

    Protein solubility is affected by ions. At low ion concentrations (<0.5 M), protein solubility increases along with ionic strength. Ions in the solution shield protein molecules from the charge of other protein molecules in what is known as 'salting-in'. At a very high ionic strength, protein solubility decreases as ionic strength increases in the process known as 'salting-out'. Thus, salting out can be used to separate proteins based on their solubility in the presence of a high concentration of salt. In this protocol, ammonium sulfate will be added incrementally to an E. coli cell lysate to isolate a recombinantly over-expressed protein of 20 kDa containing no cysteine residues or tags.

  2. Thermochemical, cloud condensation nucleation ability and optical properties of alkyl aminium sulfate aerosols

    NASA Astrophysics Data System (ADS)

    Lavi, A.; Bluvshtein, N.; Segre, E.; Segev, L.; Flores, J.; Rudich, Y.

    2013-12-01

    The increased interest in the chemistry of alkylamines and their possible roles in the atmosphere increased recently due to field observations of the correlation between new particle formation and post nucleation growth events and the presence of alkylamines in their cationic form. Due to their high saturation vapor pressure it is unlikely that short chain alkylamines will contribute to particle formation or growth by condensation. Therefore, it was previously suggested that their contribution to particulate phase is the result of acid-base reactions between the basic alkylamines and atmospherically relevant acids such as sulfuric and nitric acid. In this study we present laboratory data on the thermochemical, CCN activity and optical properties of selected atmospherically relevant alkyl aminium sulfate salts: Monomethyl aminium sulfate (MMAS), dimethyaminium sulfate (DMAS), trimethylaminium sulfate, monoethylaminium sulfate (MEAS), diethylaminium sulfate (DEAS) and triethylaminium sulfate (TEAS)). We found that the vapor pressure of these aminium salts is 1-3 orders of magnitude lower than that of ammonium sulfate and as such they can contribute to new aerosols and secondary aerosols formation. We infer that these species have very high CCN activity, with hygroscopicity parameter that is lower but close to that ammonium sulfate. Finally, we present the optical properties of these alkyl aminium sulfate salts between 360 and 420 nm. These compounds are less scattering than ammonium sulfate and show minimal wavelength dependence in this range. These compounds also do not absorb light. These derived parameters can contribute to the better understanding and characterization of the role that these compounds play in atmospheric chemical reactions, gas-solid partitioning and their possible contribution to the microphysical and radiative effects of atmospheric aerosols.

  3. Chiral Alkyl Halides: Underexplored Motifs in Medicine

    PubMed Central

    Gál, Bálint; Bucher, Cyril; Burns, Noah Z.

    2016-01-01

    While alkyl halides are valuable intermediates in synthetic organic chemistry, their use as bioactive motifs in drug discovery and medicinal chemistry is rare in comparison. This is likely attributable to the common misconception that these compounds are merely non-specific alkylators in biological systems. A number of chlorinated compounds in the pharmaceutical and food industries, as well as a growing number of halogenated marine natural products showing unique bioactivity, illustrate the role that chiral alkyl halides can play in drug discovery. Through a series of case studies, we demonstrate in this review that these motifs can indeed be stable under physiological conditions, and that halogenation can enhance bioactivity through both steric and electronic effects. Our hope is that, by placing such compounds in the minds of the chemical community, they may gain more traction in drug discovery and inspire more synthetic chemists to develop methods for selective halogenation. PMID:27827902

  4. Structural analysis of diacyl peroxides by electrospray tandem mass spectrometry with ammonium acetate: bond homolysis of peroxide-ammonium and peroxide-proton adducts.

    PubMed

    Yin, H; Hachey, D L; Porter, N A

    2000-01-01

    Organic peroxides have significant implications in organic chemistry and biological processes. The weak O-O bond makes them extremely difficult to characterize by conventional analytical methods. Diacyl peroxides are one of the major radical sources in polymerization and organic synthesis. It is well known that diacyl peroxides are thermal labile and thus are not amenable to study by gas chromatography/mass spectrometry (GC/MS). Electrospray tandem mass spectrometry (ESI-MS/MS) has been applied to the structural analysis of diacyl peroxides by formation of ammonium adducts. Collision induced dissociation (CID) studies of the ammonium adducts of the peroxide [M + NH(4)](+) give collision energy dependent fragments. For most diacyl peroxides, homolysis of the peroxy bond predominates the fragmentation pathways of the peroxide-ammonium adducts. Deuterated substrates have been employed to provide evidence for typical fragmentation pathways. The CID studies were also used to locate the O-18 in some O-18 specifically labeled diacyl peroxides. For branched alkyl or alkoxy substrates, McLafferty rearrangement and decarboxylation become a major pathway. By comparison with some anhydride analogues, ESI-MS/MS can also be used to study this class of compounds.

  5. Redox potentials in ammonium nitrate solutions

    SciTech Connect

    Ngameni, E.; Ammaa, B.B.; Wandji, R.; Bessiere, J.

    1995-03-01

    The redox potentials of M{sup n+}/M (M{sup n+} = Cu{sup 2+}, Pb{sup 2+}, Sn{sup 2+}, Cd{sup 2+}, Ag{sup +}, Zn{sup 2+}, Hg{sup 2+}), M{sup n+}/M {sup (n{minus}m)+} (Fe{sup 3+}/Fe{sup 2+}, Fe(CN){sub 6}3{minus}/Fe(CN){sub 6}{sup 4{minus}}), and AgX/Ag, X{sup {minus}} (X = Cl, Br, and I) have been measured in aqueous solutions of ammonium nitrate (1--14 M). The variation of salvation of ions, characterized by the solvent transfer coefficient f{sup tr}, is calculated from the normal redox potentials of the systems. For all the cases, the potential of the ferricinium/ferrocene system (Fe{sup +}/Fc) is used as a reference of potential. It appears as a general trend that when the concentration of salt increases from 1 to 14 M, the potentials of the systems vary slightly, indicating weak interactions between these solutes and the salt. The examined ions can be classified into two groups: those that are less solvated as the concentration of NH{sub 4}NO{sub 3} increases (CU{sup 2+}, Cd{sup 2+}, Zn{sup 2+}, Cl{sup {minus}}, Br{sup {minus}}, I{sup {minus}}) and those that are more solvated, (Pb{sup 2+}, Ag{sup +}, Hg{sup 2+}, Sn{sup 2+}). The solubility constants of the AgX salts in the H{sub 2}O + NH{sub 4}NO{sub 3} mixtures are also calculated.

  6. Analytical techniques for determining bound ammonium

    SciTech Connect

    Altaner, S.P.; Krohn, M.D

    1985-01-01

    Ammonium (NH/sub 4//sup +/) has been found to substitute for alkali cations in feldspars, micas, smectites, and alunites several Hg/Au-bearing hot springs deposits and volcanogenic stratabound Pb/Zn deposits. The authors compared four analytical techniques for determining the NH/sub 4//sup +/ content in rocks from these types of deposit and in synthetic NH/sub 4//sup +/-bearing feldspars, micas, and alunites: 1) X-ray diffraction (XRD), 2) mid- and 3) near-infrared spectroscopy (MIR and NIR) and 4) ion chromatography (IC). MIR analysis of synthetic minerals indicates that 7 ..mu..m band depth depends upon mineral type but that, for a given mineral, band depth is directly proportional to NH/sub 4//sup +/ concentration. NIR reflectance spectroscopy gives a rapid qualitative determination of NH/sub 4//sup +/ and allows positive field identification of NH/sub 4//sup +/. 4) IC gives a measure of the percent of NH/sub 4//sup +/ substitution by determining NH/sub 4//sup +/, K/sup +/, and Na/sup +/ concentrations. The procedure involves sample dissolution by HCl and HF in a microwave oven followed by separation and detection by an ion chromatograph. They estimate the detection limits of these analytical techniques for NH/sub 4//sup +/ concentration to be: XRD, 10-20% NH/sub 4//sup +/; MIR, 1-5% NG/sub 4//sup +/; and IC, <1% NH/sub 4//sup +/. Determination of NH/sub 4//sup +/ abundance in rocks will help to delineate the relationship of NH/sub 4//sup +/-bearing minerals to mineralization in ore deposits and promises to be an excellent method for prospecting.

  7. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  8. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  9. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  10. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  11. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  12. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  13. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  14. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  15. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  16. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  17. Transition metal-free decarboxylative alkylation reactions.

    PubMed

    Liu, Ping; Zhang, Guanghui; Sun, Peipei

    2016-11-22

    This review summarizes advances in the decarboxylative alkylation of carboxylic acids and their derivatives under transition metal-free conditions in recent years. Unlike most transition metal-catalyzed decarboxylative coupling reactions which tend to undergo catalytic cycles, the mechanisms of reactions under metal-free conditions are usually diverse and even ambiguous in some cases. This article offers an overview of reaction types and their corresponding mechanisms, highlights some of the advantages and limitations, and focuses on introducing UV and visible light-induced, organocatalyst and peroxide promoted radical processes for decarboxylative alkylation and the formation of C-C bonds.

  18. Alkyl ferulates in wound healing potato tubers.

    PubMed

    Bernards, M A; Lewis, N G

    1992-10-01

    Seven ferulic acid esters of 1-alkanols ranging in carbon length from C16 to C28 were synthesized and an HPLC protocol for their separation developed. Extracts prepared from wound healing potato (Solanum tuberosum) tubers and analysed by HPLC indicated that alkyl ferulate esters begin to accumulate 3-7 days after wound treatment. Of the nine esters identified by EIMS, (including two esters of odd chain length alkanols) hexadecyl and octadecyl ferulates were predominant. Alkyl ferulate esters were restricted to the wound periderm.

  19. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-01

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO-AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N2, N2O, and H2O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV' transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  20. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia

    2009-09-22

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  1. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2010-12-28

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  2. Di-ethyl-ammonium di-hydrogen orthophosphate.

    PubMed

    Held, Peter

    2014-02-01

    In the title molecular salt, [NH2(CH2CH3)2][H2PO4], two unique types of cations and anions, which are configurationally very similar, are present in the asymmetric unit. Both ions form sheets approximately parallel to (-1-1) linked by weak hydrogen bonds. The inter-connection within and between the sheets is reinforced by O-H⋯O and N-H⋯O hydrogen bonds involving the tetra-hedral H2PO4 anions and the ammonium groups.

  3. Holographic materials composed by rosin with ammonium dichromate

    NASA Astrophysics Data System (ADS)

    Ibarra-Torres, Juan Carlos; Olivares-Perez, Arturo; Ortiz-Gutierrez, Mauricio; Perez-Cortes, Mario; Iturbe Castillo, Marcelo D.

    2000-03-01

    We present a new material with potential application in holography. We have used a film of mixing ammonium dichromate with rosin resin diluted in isopropyl alcohol. This material can be easily elaborate in the laboratory. A phase grating in this material was recording using Argon-Ion laser at (lambda) equals 457 nm, showing good diffraction efficiency. This material is capable of high resolution when we record some diffraction gratings, observing 2,000 l/mm (grooves). A characteristic of the developed process is their simplicity, takes approximately 25 seconds.

  4. Rosin (colophony) holograms sensitized with ammonium dichromate ®

    NASA Astrophysics Data System (ADS)

    Olivares-Pérez, A.; Ibarra-Torres, J. C.; Ortiz-Gutiérrez, M.; Pérez-Cortés, M.; Fuentes-Tapia, I.

    2005-12-01

    We report a photosensitive emulsion by mixing ammonium dichromate with rosin resin diluted in isopropyl alcohol. This material can be easily elaborated. A phase grating in this material was recorded using an argon-ion laser at λ = 457 nm, shows a moderate diffraction efficiency. This material is capable of a high resolution when we record some diffraction gratings, observing the order of 2000 l/mm (grooves). A characteristic of the developed process is its simplicity that it takes approximately 25 s. It describes a hypothesis with respect to some mechanisms of photosensitivity in emulsions.

  5. Ammonium nonanoate broadcast application over onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonium nonanoate occurs in nature and is primarily formed from biodegradation of higher fatty acids. Racer (40% ammonium nonaoate) is a potential contact herbicide for weed control in organic crop production. Field research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determin...

  6. Biodegradation of rocket propellant waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqvi, S. M. Z.; Latif, A.

    1975-01-01

    The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

  7. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  8. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  9. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  10. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  11. Simple Quaternary Ammonium Ions R4N + ( R= nPr, nBu, nPen) as Versatile Structure Directors for the Synthesis of Zeolite-Like, Heterobimetallic Cyanide Frameworks

    NASA Astrophysics Data System (ADS)

    Poll, Eyck-Michael; Samba, Sabine; Dieter Fischer, R.; Olbrich, Falk; Davies, Nicola A.; Avalle, Paolo; Apperley, David C.; Harris, Robin K.

    2000-06-01

    The preparation of three new examples of water insoluble host/guest assemblies of the general composition: [(R4N)(Me3Sn)2M(CN)6·zH2O] (R=n-propyl or n-pentyl, M=Fe or Co, 0≤z≤2) from likewise polymeric super-Prussian-blue derivatives [(Me3Sn)3M(CN)6] and aqueous (R4N)X solutions are reported. According to combined single-crystal X-ray (3a and 3a*: R=nPr, M=Co, z=2; 5b: R=nPen, M=Fe, z=0.5), powder X-ray diffraction (XRD), and multinuclear (13C, 15N, 59Co, 119Sn) CPMAS solid-state magnetic resonance studies, 3a and 3a* contain cis- and trans-isomeric [Co(CN)4(CNSnMe3OH2)2]- building blocks, respectively, which are held together exclusively by Sn←OH2···NC-Co hydrogen bonds. In striking contrast, the building blocks of 5b and 5a are infinite [M-CN-Sn-NC] chains. In all these assemblies, also significant C-H···NC hydrogen bonds between the encapsulated R4N+ guest ion and exclusively terminal cyanide ligands of the host seem to play a notable auxiliary role.

  12. Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds.

    PubMed

    Heuger, Gerold; Göttlich, Richard

    2015-01-01

    N-Alkyl-N-chlorosulfonamides add to alkenes under copper(I) catalysis. In reactions of styrene derivatives with terminal double bonds the addition products were obtained in excellent yield and high regioselectivity. Lower yields are obtained in addition reactions to non-aromatic alkenes. The reaction most likely proceeds via a redox catalysis and amidyl radicals, a concerted mechanism has been ruled out and a polar mechanism via chloronium ions would lead to the opposite regiochemistry.

  13. Ammonium nitrogen in fetuses of urea-treated sheep.

    PubMed

    Yelverton, C C; Roller, M H; Swanson, R N

    1975-02-01

    Eight pregnant Southdown ewes were treated (by drench) with 12.5 ml of 3.3 M urea solution per kilogram of body weight, and ammonium nitrogen concentrations of blood and tissues of these ewes and their fetuses were measured and compared with those of control ewes (given water by drench) and their fetuses. Blood ammonium nitrogen (BAN) and tissue ammonium nitrogen (TAN) concentrations for liver, kidney, spleen, and muscle of ewes and fetuses were determined by an ion-exchange procedure. Samples of blood were collected before treatment, at 30, 90 and 150 minutes after treatment, and at death of the dam. The principal ewes had increasing BAN concentrations with time after drench, and their fetuses had significantly greater (P less than 0.01) BAN concentrations than fetuses from control ewes. All fetuses were alive after death of the dams and had lower TAN values than their dams. The differences in ammonia concentrations between ewes and fetuses were larger in the principal group than in the control group. Except for ewe muscle and fetal liver, all tissues of principals had significantly greater (P less than 0.01) TAN concentrations than those of controls. Muscle of principal ewes and hepatic tissues of their fetuses had greater (P less than 0.05) TAN concentrations than those of control ewes and their fetuses.

  14. Evolution of Electrogenic Ammonium Transporters (AMTs)

    PubMed Central

    McDonald, Tami R.; Ward, John M.

    2016-01-01

    The ammonium transporter gene family consists of three main clades, AMT, MEP, and Rh. The evolutionary history of the AMT/MEP/Rh gene family is characterized by multiple horizontal gene transfer events, gene family expansion and contraction, and gene loss; thus the gene tree for this family of transporters is unlike the organismal tree. The genomes of angiosperms contain genes for both electrogenic and electroneutral ammonium transporters, but it is not clear how far back in the land plant lineage electrogenic ammonium transporters occur. Here, we place Marchantia polymorpha ammonium transporters in the AMT/MEP/Rh phylogeny and we show that AMTs from the liverwort M. polymorpha are electrogenic. This information suggests that electrogenic ammonium transport evolved at least as early as the divergence of bryophytes in the land plant lineage. PMID:27066024

  15. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  16. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  17. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  18. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  19. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  20. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  1. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  2. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  3. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  4. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    EPA Science Inventory

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  5. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  6. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  7. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  8. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  9. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  10. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  11. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  12. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  13. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  14. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  15. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  16. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  17. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  18. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  19. 40 CFR 721.10699 - Polyfluorinated alkyl thio acrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thio acrylamide... Specific Chemical Substances § 721.10699 Polyfluorinated alkyl thio acrylamide (generic). (a) Chemical... as polyfluorinated alkyl thio acrylamide (PMN P-11-529) is subject to reporting under this...

  20. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  1. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  2. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  3. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  4. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  5. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  6. Copper-catalyzed radical carbooxygenation: alkylation and alkoxylation of styrenes.

    PubMed

    Liao, Zhixiong; Yi, Hong; Li, Zheng; Fan, Chao; Zhang, Xu; Liu, Jie; Deng, Zixin; Lei, Aiwen

    2015-01-01

    A simple copper-catalyzed direct radical carbooxygenation of styrenes is developed utilizing alkyl bromides as radical resources. This catalytic radical difunctionalization accomplishes both alkylation and alkoxylation of styrenes in one pot. A broad range of styrenes and alcohols are well tolerated in this transformation. The EPR experiment shows that alkyl halides could oxidize Cu(I) to Cu(II) in this transformation.

  7. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  8. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  9. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  10. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  11. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  12. Poly(ethyleneoxide) functionalization through alkylation

    DOEpatents

    Sivanandan, Kulandaivelu; Eitouni, Hany Basam; Li, Yan; Pratt, Russell Clayton

    2015-04-21

    A new and efficient method of functionalizing high molecular weight polymers through alkylation using a metal amide base is described. This novel procedure can also be used to synthesize polymer-based macro-initiators containing radical initiating groups at the chain-ends for synthesis of block copolymers.

  13. Synthesis and characterization of chitosan alkyl urea.

    PubMed

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations.

  14. 77 FR 72747 - Alkyl(C8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... Classification System (NAICS) codes is not intended to be exhaustive, but rather provides a guide to help readers.../reproductive screening test (OECD 422) toxicity study on a representative N- alkyl(C 8 -C 18... in the reproductive or developmental parameters examined. No systemic toxicity was observed in...

  15. Antimalarial activity of compounds interfering with Plasmodium falciparum phospholipid metabolism: comparison between mono- and bisquaternary ammonium salts.

    PubMed

    Calas, M; Ancelin, M L; Cordina, G; Portefaix, P; Piquet, G; Vidal-Sailhan, V; Vial, H

    2000-02-10

    On the basis of a previous structure-activity relationship study, we identified some essential parameters, e.g. electronegativity and lipophilicity, required for polar head analogues to inhibit Plasmodium falciparum phospholipid metabolism, leading to parasite death. To improve the in vitro antimalarial activity, 36 cationic choline analogues consisting of mono-, bis-, and triquaternary ammonium salts with distinct substituents of increasing lipophilicity were synthesized. For monoquaternary ammonium salts, an increase in the lipophilicity around nitrogen was beneficial for antimalarial activity: IC(50) decreased by 1 order of magnitude from trimethyl to tripropyl substituents. Irrespective of the polar head substitution (methyl, ethyl, hydroxyethyl, pyrrolidinium), increasing the alkyl chain length from 6 to 12 methylene groups always led to increased activity. The highest activity was obtained for the N,N,N-tripropyl-N-dodecyl substitution of nitrogen (IC(50) 33 nM). Beyond 12 methylene groups, the antimalarial activities of the compounds decreased slightly. The structural requirements for bisquaternary ammonium salts in antimalarial activity were very similar to those of monoquaternary ammonium salts, i.e. polar head steric hindrance and lipophilicity around nitrogen (methyl, hydroxyethyl, ethyl, pyrrolidinium, etc.). In contrast, with bisquaternary ammonium salts, increasing the lipophilicity of the alkyl chain between the two nitrogen atoms (from 5 to 21 methylene groups) constantly and dramatically increased the activity. Most of these duplicated molecules had activity around 1 nM, and the most lipophilic compound synthesized exhibited an IC(50) as low as 3 pM (21 methylene groups). Globally, this oriented synthesis produced 28 compounds out of 36 with an IC(50) lower than 1 microM, and 9 of them had an IC(50) in the nanomolar range, with 1 compound in the picomolar range. This indicates that developing a pharmacological model for antimalarial compounds

  16. Nanomodified vermiculite NMV - a new material for recycling ammonium nitrogen

    NASA Astrophysics Data System (ADS)

    Rama, Miradije; Laiho, Taina; Eklund, Olav; Lehto, Kirsi; Shebanov, Alex; Smått, Jan-Henrik

    2016-04-01

    Vermiculites ((Mg,Fe,Al)3(Al,Si)4O10(OH)24H2O) are naturally occurring minerals from hydromica group with a high cation exchange capacity and large surface area. Since vermiculite is a hydrated mineral, its structure can be changed with heat. In this study vermiculite samples were heated in an oven until the interlayer distance of them diminished from 14 Å to 11.7 Å. This method for improving vermiculites intake of ammonium ions by heating, is an invention made at the University of Turku. Nanomodified vermiculite (NMV) is able to absorb up to 4.7 wt% of ammonium. NMV can be used as an efficient filter and immobilizer of ammonium in different environments. NMV has been efficiently tested on waste water from a biogas plant, human urine, combustion experiments, industrial chimneys, excrements from farms etc. Ammonium doped vermiculite (ADV) is further developed for fertilizer use. Performed experiments have testified the usability of ADV as a fertilizer. At first step the NMV was processed with the reject water from a biogas plant, were it absorbed NH4+ into the lattice. At second, the ADV was used as nutrient source for garden plants. Geraniums and begonias were used as test plants of the work. Plant growth rate was evaluated based on plant weight. Results showed that significant increase of the growth of geraniums and of begonias were observed when comparing to those cultivations where plants have got normal fertilization. Moreover, ADV has been tested as a fertilizer in greenhouse experiments with spruces and pines. After five months, the weight of the plants that had grown in a substrate containing ADV was 10 times the weight of plants growing in the reference substrate.

  17. Effects of alkyl chain length on properties of 1-alkyl-3-methylimidazolium fluorohydrogenate ionic liquid crystals.

    PubMed

    Xu, Fei; Matsumoto, Kazuhiko; Hagiwara, Rika

    2010-11-15

    A series of 1-alkyl-3-methylimidazolium fluorohydrogenate salts (C(x)MIm(FH)(2)F, x=8, 10, 12, 14, 16, and 18) have been characterized by thermal analysis, polarized optical microscopy, IR spectroscopy, X-ray diffraction, and anisotropic ionic conductivity measurements. Liquid crystalline mesophases with a smectic A interdigitated bilayer structure are observed from C(10) to C(18), showing a fan-like or focal conic texture. The temperature range of the mesophase increases with the increase in the alkyl chain length (from 10.1 °C for C(10)MIm(FH)(2)F to 123.1 °C for C(18)MIm(FH)(2)F). The distance between the two layers in the smectic structure gradually increases with increasing alkyl chain length and decreases with increasing temperature. Conductivity parallel to the smectic layers is around 10 mS cm(-1) regardless of the alkyl chain length, whereas that perpendicular to the smectic layers decreases with increasing alkyl chain length because of the thicker insulating sheet with the longer alkyl chain.

  18. Effects of quaternary ammonium chain length on antibacterial bonding agents.

    PubMed

    Li, F; Weir, M D; Xu, H H K

    2013-10-01

    The objectives of this study were to synthesize new quaternary ammonium methacrylates (QAMs) with systematically varied alkyl chain lengths (CL) and to investigate, for the first time, the CL effects on antibacterial efficacy, cytotoxicity, and dentin bond strength of bonding agents. QAMs were synthesized with CL of 3 to 18 and incorporated into Scotchbond Multi-Purpose (SBMP) bonding agent. The cured resins were inoculated with Streptococcus mutans. Bacterial early attachment was investigated at 4 hrs. Biofilm colony-forming units (CFU) were measured after 2 days. With CL increasing from 3 to 16, the minimum inhibitory concentration and minimum bactericidal concentration were decreased by 5 orders of magnitude. Incorporating QAMs into SBMP reduced bacterial early attachment, with the least colonization at CL = 16. Biofilm CFU for CL = 16 was 4 log lower than SBMP control (p < .05). All groups had similar dentin bond strengths (p > .1). The new antibacterial materials had fibroblast/odontoblast viability similar to that of commercial controls. In conclusion, increasing the chain length of new QAMs in bonding agents greatly increased the antibacterial efficacy. A reduction in Streptococcus mutans biofilm CFU by 4 log could be achieved, without compromising bond strength and cytotoxicity. New QAM-containing bonding agents are promising for a wide range of restorations to inhibit biofilms.

  19. Effects of Quaternary Ammonium Chain Length on Antibacterial Bonding Agents

    PubMed Central

    Li, F.; Weir, M.D.; Xu, H.H.K.

    2013-01-01

    The objectives of this study were to synthesize new quaternary ammonium methacrylates (QAMs) with systematically varied alkyl chain lengths (CL) and to investigate, for the first time, the CL effects on antibacterial efficacy, cytotoxicity, and dentin bond strength of bonding agents. QAMs were synthesized with CL of 3 to 18 and incorporated into Scotchbond Multi-Purpose (SBMP) bonding agent. The cured resins were inoculated with Streptococcus mutans. Bacterial early attachment was investigated at 4 hrs. Biofilm colony-forming units (CFU) were measured after 2 days. With CL increasing from 3 to 16, the minimum inhibitory concentration and minimum bactericidal concentration were decreased by 5 orders of magnitude. Incorporating QAMs into SBMP reduced bacterial early attachment, with the least colonization at CL = 16. Biofilm CFU for CL = 16 was 4 log lower than SBMP control (p < .05). All groups had similar dentin bond strengths (p > .1). The new antibacterial materials had fibroblast/odontoblast viability similar to that of commercial controls. In conclusion, increasing the chain length of new QAMs in bonding agents greatly increased the antibacterial efficacy. A reduction in Streptococcus mutans biofilm CFU by 4 log could be achieved, without compromising bond strength and cytotoxicity. New QAM-containing bonding agents are promising for a wide range of restorations to inhibit biofilms. PMID:23958761

  20. Ammonium toxicity at high pH in a marine bioassay using Corophium volutator.

    PubMed

    Kater, Belinda J; Dubbeldam, Marco; Postma, Jaap F

    2006-10-01

    Two forms of ammonium exist in water: un-ionized ammonia NH3 and ionized ammonium NH4+. The toxicity to many aquatic organisms is primarily attributed to the NH3 (un-ionized) species, with the NH4+ ion (ionized) species being relatively less toxic. The pH level influences the degree of ionization. It is therefore very important that quality criteria be derived for total ammonium levels at several pH values in order to allow correct interpretation of the sediment bioassay with Corophium volutator. The responses of Corophium to total ammonium were studied in a series of pH-controlled experiments. The LC50 of total ammonium showed a significant decrease with increasing pH, in both water-only and sediment experiments. The results indicated a combined NH4+ and NH3 toxicity at pH levels less than 8.3. The results can be used to set pH-dependent water quality criteria for total ammonium in overlying water in a 10-day sediment bioassay with Corophium volutator.

  1. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1997-09-01

    The need to increase throughput in alkylation plants has resulted in higher operating temperatures and higher water levels in alkylation acids than projected by design. Combined with higher flow rates, the more severe process environment causes carbon steel to corrode at increased rates. Carbon steel is the main material of construction for horizontal contactors (Stratco reactors). A leak to the atmosphere in the hydraulic end cone of one contactor and the realization that basic corrosion data are not available for high throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in alkylation unit horizontal contactors is successfully mitigated by saturating fresh alkylation acid with ferrous sulfate.

  2. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  3. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  4. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  5. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  6. Simultaneous removal of ammonium and phosphate by alkaline-activated and lanthanum-impregnated zeolite.

    PubMed

    He, Yinhai; Lin, Hai; Dong, Yingbo; Liu, Quanli; Wang, Liang

    2016-12-01

    Simultaneous ammonium and phosphate removal characteristics and mechanism, as well as the major influencing factors, such as pH, temperature and co-existing ions, onto NaOH-activated and lanthanum-impregnated zeolite (NLZ) were investigated. The phosphate adsorption increases from 0.2 mg g(-1) for natural zeolite up to 8.96 mg g(-1) for NLZ, while only a slight decrease on the ammonium adsorption capacity from 23.9 mg g(-1) for NaOH-activated zeolite to 21.2 mg g(-1) for NLZ was observed. The ammonium and phosphate adsorption showed little pH dependence in the range from pH 3 to 7, while it decreased sharply with the pH increased above pH 7. Adsorption of ammonium and phosphate could be well described by the pseudo-second-order model and the process was mainly governed by intra-particle diffusion. The Langmuir and Freundlich model can be acceptably applied to fit the experimental data, which suggested that adsorption was caused by both the monolayer and homogeneous coverage at specific and equal affinity sites available NLZ. The underlying mechanism for the specific adsorption of phosphate by NLZ was revealed with the aid of SEM-EDS, XPS, and FTIR analysis, and the formation of (LaO)(OH)PO2 was verified to be the dominant pathway for selective phosphate adsorption by lanthanum-impregnated zeolite. While the removal mechanism of ammonium could be well interpreted by SEM-EDS, FTIR and ICP analysis, and ion-exchange was expected to be the main removal process for ammonium. The results indicate that NLZ could efficiently and simultaneously remove low concentration of ammonium and phosphate from contaminated waters.

  7. Phase diagram of ammonium nitrate

    SciTech Connect

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-07

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ′} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  8. Synthesis, characterization and thermal properties of small R2R‧2N+X--type quaternary ammonium halides

    NASA Astrophysics Data System (ADS)

    Busi, Sara; Lahtinen, Manu; Mansikkamäki, Heidi; Valkonen, Jussi; Rissanen, Kari

    2005-06-01

    Twenty-one R2R'2N +X- -type ( R=methyl or ethyl, R'=alkyl, X=Br or I) quaternary ammonium (QA) halides have been prepared by using a novel one-pot synthetic route in which a formamide (dimethyl-, diethylformamide, etc.) is treated with alkyl halide in the presence of sodium or potassium carbonate. The formation of QA halides was verified with 1H-NMR, 13C-NMR, MS and elemental analysis. The crystal structures of four QA halides (two bromide and two iodide) were determined using X-ray single crystal diffraction, and the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bulk material. The thermal properties of all compounds were studied using TG/DTA and DSC methods. The smallest compounds decomposed during or before melting. The decreasing trend of melting points was observed when the alkyl chain length was increased. The liquid ranges of 120-180 °C were observed for compounds with 5-6 carbon atoms in the alkyl chain. The low melting points and wide liquid ranges suggest potential applicability of these compounds for example as ionic liquids precursors.

  9. Stereoselective Alkylation of the Vinylketene Silyl N,O-Acetal and Its Application to the Synthesis of Mycocerosic Acid.

    PubMed

    Nakamura, Tatsuya; Kubota, Kei; Ieki, Takanori; Hosokawa, Seijiro

    2016-01-04

    Stereoselective alkylation of the vinylketene silyl N,O-acetal possessing a chiral auxiliary has been achieved by using activated alkyl halides including allyl iodides, benzyl iodides, and propargyl iodide with Ag(I) ion in the presence of BF3·OEt2. The reaction proceeded to give reduced polyketides in high stereoselectivity. The synthesis of mycocerosic acid, a component of the cell envelope of Mycobacterium tuberculosis, has been accomplished by this methodology. During the synthetic studies, 2-methylbenzimidazole was found to be a bulky proton source which worked in the presence of liquid ammonia.

  10. Searches for new alkylation catalysts, processes forge ahead

    SciTech Connect

    Rhodes, A.

    1994-08-22

    As a result of the hazardous properties of hydrofluoric acid (HF), HF alkylation has been the subject of much recent controversy. The safety and environmental requirements associated with the HF alkylation processes continue to drive industry to develop new alkylation technologies. In fact, several major process licensors are well on their ways to bringing these new technologies to market. The new alkylation processes under development center around new, less-harmful catalysts. Although this work is progressing rapidly, an update of the status of some of these new processes will keep refiners abreast of the new options they may soon have for building new alkylation units or retrofitting existing ones. The process development and economics are described for a Topsoe/Kellogg fixed bed alkylation process and the Kerr-McGee homogeneous alkylation technology process.

  11. Synthesis and structure-activity study of quaternary ammonium functionalized beta-cyclodextrin-carboxymethylcellulose polymers.

    PubMed

    Bonenfant, Danielle; Bourgeois, François-René; Mimeault, Murielle; Monette, Frédéric; Niquette, Patrick; Hausler, Robert

    2011-01-01

    Carboxymethylcellulose (CMC) and beta-cyclodextrin (beta-CD)-based polymers functionalized with two types of quaternary ammonium compounds (QACs), the alkaquat DMB-451 (N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride) (DMD-451) named polymer DMB-451, and FMB 1210-8 (a blend of 32 w% N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride and 48 w% of didecyldimethylammonium chloride) named polymer FMB 1210-8, were synthethized and characterized by Fourier transform infrared spectroscopy. The antimicrobial activities of these polymers against Eschericia coli were also evaluated at 25 degrees C in wastewater. The results have indicated that the polymer FMB 1210-8 possesses a high-affinity binding with bacterial cells that induces a rapid disinfection process. Moreover, in the same experimental conditions of disinfection (mixture of 1.0 g of polymer and 100 mL of wastewater), the polymer FMB 1210-8 has a higher antimicrobial efficiency (99.90%) than polymer DMB-451 (92.8%). This phenomenon might be associated to a stronger interaction with bacterial cells due to stronger binding affinity for E. coli cells and greater killing efficiency of the C10 alkyl chains QAC of polymer FMB 1210-8 to disrupt the bacterial cell membrane as compared to N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride. Together, these results suggest that the polymer FMB 1210-8 could constitute a good disinfectant against Escherichia coli, which could be advantageously used in wastewater treatments due to the low toxicity of beta-CD and CMC, and moderated toxicity of FMB 1210-8 to human and environment.

  12. Impact of chain length on antibacterial activity and hemocompatibility of quaternary N-alkyl and n,n-dialkyl chitosan derivatives.

    PubMed

    Sahariah, Priyanka; Benediktssdóttir, Berglind E; Hjálmarsdóttir, Martha Á; Sigurjonsson, Olafur E; Sørensen, Kasper K; Thygesen, Mikkel B; Jensen, Knud J; Másson, Már

    2015-05-11

    A highly efficient method for chemical modification of chitosan biopolymers by reductive amination to yield N,N-dialkyl chitosan derivatives was developed. The use of 3,6-O-di-tert-butyldimethylsilylchitosan as a precursor enabled the first 100% disubstitution of the amino groups with long alkyl chains. The corresponding mono N-alkyl derivatives were also synthesized, and all the alkyl compounds were then quaternized using an optimized procedure. These well-defined derivatives were studied for antibacterial activity against Gram positive S. aureus, E. faecalis, and Gram negative E. coli, P. aeruginosa, which could be correlated to the length of the alkyl chain, but the order was dependent on the bacterial strain. Toxicity against human red blood cells and human epithelial Caco-2 cells was found to be proportional to the length of the alkyl chain. The most active chitosan derivatives were found to be more selective for killing bacteria than the quaternary ammonium disinfectants cetylpyridinium chloride and benzalkonium chloride, as well as the antimicrobial peptides melittin and LL-37.

  13. Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. V. Spectra of protiated and partially deuterated magnesium ammonium arsenate hexahydrate (arsenstruvite)

    NASA Astrophysics Data System (ADS)

    Stefov, V.; Šoptrajanov, B.; Najdoski, M.; Engelen, B.; Lutz, H. D.

    2008-01-01

    The Fourier transform infrared and Raman spectra of magnesium ammonium arsenate hexahydrate, MgNH 4AsO 4 · 6H 2O (arsenstruvite) and of its deuterated analogues were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). Not surprisingly, the spectra show pronounced similarities with the corresponding spectra of the previously studied magnesium potassium phosphate hexahydrate and magnesium ammonium phosphate hexahydrate with the expected differences in the regions of the arsenate vibrations. The main contribution to the intensity of the complex feature in the X-H stretching region (X being O or N) comes from the stretching vibrations of the water molecules, whereas the vibrations of the ammonium ions are less important as long as the intensity is concerned. This is due not only to the fact that four crystallographically different water molecules of crystallization exist in the structure (as compared with a single type of ammonium ions) but also because the hydrogen bonds formed by the water molecules are much stronger than those in which the ammonium ions take part. Difference infrared spectra were obtained by subtracting the properly normalized spectrum of the protiated compound from the spectrum of a deuterated analogue with low deuterium content. As evidenced by the spectra of the partially deuterated analogues and by the difference spectra, vibrational interactions are present in the crystal. Probably the most dramatic is the result of such an interaction producing a deep Evans-type hole in the stretching region of the difference spectrum but additional cases of vibrational mixing are found in the low-frequency region.

  14. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  15. Toxicology of ammonium sulfate in the lung

    SciTech Connect

    Pepelko, W.E.; Mattox, J.K.; Cohen, A.L.

    1980-01-01

    Despite the relatively low toxicity of ammonium sulfate in experimental animals, it cannot be concluded that increased sulfuric acid production is harmless to human health. Many other pollutants are present in ambient air with possible synergistic effects. Sulfuric acid undoubtedly reacts to produce other sulfates in ambient air which are often much more toxic. For example zinc sulfate and zinc ammonium sulfate are much more irritating to the lung than ammonium sulfate. In order to assess with more certainty the health effects of increased sulfuric acid production, it will be necessary to determine accurately that proportion inhaled as free sulfuric acid compared with ammonium sulfate as well as the proportion and kinds of other sulfates present in the atmosphere.

  16. 76 FR 46907 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-03

    ... used in agricultural operations indicated that ammonium nitrate is the best choice for nitrogen... contains not less than 33 percent nitrogen by weight.'' See 6 U.S.C. 488(1)(A). DHS proposes to use...

  17. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  18. In pursuit of homoleptic actinide alkyl complexes.

    PubMed

    Seaman, Lani A; Walensky, Justin R; Wu, Guang; Hayton, Trevor W

    2013-04-01

    This Forum Article describes the pursuit of isolable homoleptic actinide alkyl complexes, starting with the pioneering work of Gilman during the Manhattan project. The initial reports in this area suggested that homoleptic uranium alkyls were too unstable to be isolated, but Wilkinson demonstrated that tractable uranium alkyls could be generated by purposeful "ate" complex formation, which serves to saturate the uranium coordination sphere and provide the complexes with greater kinetic stability. More recently, we reported the solid-state molecular structures of several homoleptic uranium alkyl complexes, including [Li(THF)4][U(CH2(t)Bu)5], [Li(TMEDA)]2[UMe6], [K(THF)]3[K(THF)2][U(CH2Ph)6]2, and [Li(THF)4][U(CH2SiMe3)6], by employing Wilkinson's strategy. Herein, we describe our attempts to extend this chemistry to thorium. The treatment of ThCl4(DME)2 with 5 equiv of LiCH2(t)Bu or LiCH2SiMe3 at -25 °C in THF affords [Th(CH2(t)Bu)5] (1) and [Li(DME)2][Th(CH2SiMe3)5 (2), respectively, in moderate yields. Similarly, the treatment of ThCl4(DME)2 with 6 equiv of K(CH2Ph) produces [K(THF)]2[Th(CH2Ph)6] (3), in good yield. Complexes 1-3 have been fully characterized, while the structures of 1 and 3 were confirmed by X-ray crystallography. Additionally, the electronic properties of 1 and 3 were explored by density functional theory.

  19. Soluble Alkyl Substituted Polygermanes. Thermochromic Behavior.

    DTIC Science & Technology

    1986-07-17

    are strongly thermochromic . The effect is attributed to conformational locking of the backbone which is caused by the crystallization of the side groups...are strongly thermochromic . The effect is attributed to the conformational locking of the backbone which is caused by the crystallization of the side...SYMBOL. 02 &m A -- .- h.. .. .. . . . . . . . . ... . . . .. RJ 5008 (52258) 1/24/86 Chemis try SOLUBLE ALKYL SUBSTITUTED POLYGERMANES: THERMOCHROMIC

  20. ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

    DOEpatents

    Long, R.L.

    1958-09-30

    A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

  1. Electrochemically and bioelectrochemically induced ammonium recovery.

    PubMed

    Gildemyn, Sylvia; Luther, Amanda K; Andersen, Stephen J; Desloover, Joachim; Rabaey, Korneel

    2015-01-22

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems.

  2. Electrochemically and Bioelectrochemically Induced Ammonium Recovery

    PubMed Central

    Gildemyn, Sylvia; Luther, Amanda K.; Andersen, Stephen J.; Desloover, Joachim; Rabaey, Korneel

    2015-01-01

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems. PMID:25651406

  3. The Scarlet Letter of Alkylation: A Mini Review of Selective Alkylating Agents

    PubMed Central

    Oronsky, Bryan T; Reid, Tony; Knox, Susan J; Scicinski, Jan J

    2012-01-01

    If there were a stigma scale for chemotherapy, alkylating agents would be ranked at the top of the list. The chemical term alkylation is associated with nonselective toxicity, an association that dates back to the use of nitrogen mustards during World War I as chemical warfare agents. That this stigma persists and extends to compounds that, through selectivity, attempt to “tame” the indiscriminate destructive potential of alkylation is the subject of this review. Selective alkylation, as it is referred to herein, constitutes an extremely nascent and dynamic field in oncology. The pharmacodynamic response to this selective strategy depends on a delicate kinetic balance between specificity and the rate and extent of binding. Three representative compounds are presented: RRx-001, 3-bromopyruvate, and TH-302. The main impetus for the development of these compounds has been the avoidance of the serious complications of traditional alkylating agents; therefore, it is the thesis of this review that they should not experience stigma by association. PMID:22937173

  4. Hydrolysis of p-nitrophenyl esters promoted by semifluorinated quaternary ammonium polymer latexes and films.

    PubMed

    Kaur, Baljinder; McBride, Sean P; Paul, Abhijit; Ford, Warren T

    2010-10-19

    Semifluorinated polymer latexes were prepared by emulsion polymerization of 2.5-25% of a fluoroalkyl methacrylate, 25% chloromethylstyrene, 1% styrylmethyl(trimethyl)ammonium chloride, and the remainder 2-ethylhexyl methacrylate under surfactant-free conditions. The chloromethylstyrene units were converted to quaternary ammonium ions with trimethylamine. In aqueous dispersions at particle concentrations of less than 1 mg mL(-1) the quaternary ammonium ion latexes promoted hydrolyses of p-nitrophenyl hexanoate (PNPH) in pH 9.4 borate buffer and of diethyl p-nitrophenyl phosphate (Paraoxon) in 0.1 M NaOH at 30 °C with half-lives of less than 10 min. Thin 0.7-2 μm films of the latexes on glass promoted fast hydrolysis of Paraoxon but not of PNPH under the same conditions. Even after annealing the quaternary ammonium ion polymer films at temperatures well above their glass transition temperatures, AFM images of the film surfaces had textures of particles. Contact angle measurements of the annealed films against water and against hexadecane showed that the surfaces were not highly fluorinated.

  5. Tetrahydrofurfuryloxide derivatives of alkyl aluminum species.

    SciTech Connect

    Boyle, Timothy J.; Avilucea, Gabriel; Bunge, Scott D.; Alam, Todd Michael; Rodriguez, Mark Andrew; Cherry, Brian Ray; Tissot, Ralph George, Jr.; Segall, Judith M.

    2004-12-01

    Tetrahydrofurfuryl alcohol (H-OTHF) was successfully reacted with a series of aluminum alkyls (AlR{sub 3}) to yield compounds of the general formula [R{sub 2}Al({mu}-OTHF)]{sub 2} where R = CH{sub 3} (1), CH{sub 2}CH{sub 3} (2), and CH{sub 2}CH(CH{sub 3}){sub 2} (3). Further, reactivity studies showed that the alkyls for 1 were easily exchanged, forming compounds of the general formula [Me(OR)Al({mu}-OTHF)]{sub 2} where OR = OC{sub 6}H{sub 3}(Me){sub 2}-2,6 (4), OC{sub 6}H{sub 3}(CMe{sub 3}){sub 2}-2,6 (5a), and OSi(C{sub 6}H5){sub 3} (6). For 5a, reflux temperatures were required to get the full exchange; otherwise the asymmetric derivative [Me(OR)Al({mu}-OTHF){sub 2}AlMe{sub 2}] (5b) was isolated. The bulk powders of 1-6 were found to be in agreement with the crystal structures on the basis of elemental analyses and multinuclear solid state NMR studies. Multinuclear solution state NMR studies indicate that the alkyl OTHF derivatives have cis/trans isomers due to the chiral proton on the OTHF ligand.

  6. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Quaternary ammonium chloride combination. 172.165... § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride... the following compounds: n-dodecyl dimethyl benzyl ammonium chloride (CAS Reg. No. 139-07-1);...

  7. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  8. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  9. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  10. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron ammonium citrate. 172.430 Section 172.430 Food... Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  11. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560... Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal feed... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  12. Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. III. Spectra of protiated and partially deuterated magnesium ammonium phosphate hexahydrate

    NASA Astrophysics Data System (ADS)

    Stefov, V.; Šoptrajanov, B.; Kuzmanovski, I.; Lutz, H. D.; Engelen, B.

    2005-10-01

    Magnesium ammonium phosphate hexahydrate, MgNH 4PO 4·6H 2O (synthetic struvite) is a well-known biomineral, its major biological importance being related to its presence in human urinary sediments and vesical and renal calculi. The Fourier transform infrared and Raman spectra of magnesium ammonium phosphate hexahydrate were recorded and analyzed from room temperature (RT) down to the boiling temperature of liquid nitrogen (LNT). Also recorded and analyzed were the spectra of its partially deuterated analogues. The recorded spectra were compared with the corresponding ones of the previously studied potassium analogue. On the basis of such a comparison it was concluded that the main contribution to the intensity of the broad and structured feature in the O-H/N-H stretching region comes from the bands originating from the H-O-H stretches. The location of at least some of the stretching vibrations of the ammonium ions (albeit one of its deuterated forms) is possible in the spectrum of the sample containing ≈2% deuterium. The bands at 2326 and 2277 cm -1 (and probably, at least partially, that at 2393 cm -1) can be assigned with certainty to N-D stretching vibrations of isotopically isolated NH 3D + ions. The LNT Raman bands at 1702 and 1685 cm -1 are attributed to the ν2NH4+ mode and those at 1477 and 1442 cm -1 are observed are attributed to the ν4 mode. The relatively high frequencies (1302 and 1295 cm -1) of some of the bands due to the ND bending vibrations of isotopically isolated NH 3D + ions are in line with the existence of quite strong hydrogen bonds formed by ammonium ions. The librations of the deuterated forms of water molecules may be coupled with the components of the phosphate ν4 vibration.

  13. U-shaped conformation of alkyl chains bound to a synthetic receptor cucurbit[8]uril.

    PubMed

    Ko, Young Ho; Kim, Youngkook; Kim, Hyunuk; Kim, Kimoon

    2011-02-01

    The behavior of a series of alkanes bound to the molecular host cucurbit[8]uril (CB[8]) has been systematically studied by 2D (1)H NMR spectroscopy and isothermal titration calorimetry (ITC). CB[8] and alkyltrimethylammonium (C(m) TA(+), (CH(3))(3)N(+)C(m)H(2m+1), m=6-16) form 1:1 host-guest complexes with a high binding constant (K≈10(6) m(-1)). The shortest hexyl chain of C(6)TA(+) can be fully encapsulated in an extended conformation inside the CB[8] cavity, which is driven by both enthalpy and entropy. However, for the longer aliphatic chains, C(8)-C(16), the long alkyl tails take a U-shaped conformation inside the cavity, and their complexation is dominantly or almost exclusively enthalpy-driven, owing to the increased van der Waals contact between the folded aliphatic chain and the inner wall of the host cavity. As the chain length increases from C(8) to C(16), the ammonium head group of the guests moves away from the portal of CB[8] while the long aliphatic tails maintain the U-shaped conformation inside the cavity. The complexation of C(m)TA(+) with CB[8] follows the enthalpy-entropy compensation rule commonly observed in molecular recognition systems. For example, among the guest molecules, C(12)TA(+) shows the highest enthalpic gain (most favorable), owing to the large van der Waals contact between the guest and the host cavity, and at the same time the most unfavorable entropic contribution, owing to the severe conformational restriction of the U-shaped alkyl chain inside the host. The enthalpy-entropy compensation plot for the complexation suggests large conformational changes of the long alkyl chains and extensive dehydration associated with the inclusion complex formation.

  14. Enhanced electrochemical performance of ammonium vanadium bronze through sodium cation intercalation and optimization of electrolyte.

    PubMed

    Fei, Hailong; Liu, Xin; Li, Huan; Wei, Mingdeng

    2014-03-15

    A new type of platelet-like ammonium vanadium bronze (NH4)2V6O16 is first used as cathode material for Na-ion battery. The discharge capacity and cycling stability is improved by the intercalation of Na(+) and using NaPF6 as electrolyte. Raman spectrum shows that the crystalline structure of (NH4)2V6O16 is changed after the intercalation of Na(+) to (NH4)2V6O16. Furthermore, the obtained sodium ammonium vanadium bronze shows smaller charge transfer resistance than (NH4)2V6O16, which would favor superior discharge capacity and good cycling stability. Additionally, NaPF6 is prior to NaClO4 as electrolyte for ammonium vanadium bronze cathode materials.

  15. Effects of alkyl parabens on plant pathogenic fungi.

    PubMed

    Ito, Shinsaku; Yazawa, Satoru; Nakagawa, Yasutaka; Sasaki, Yasuyuki; Yajima, Shunsuke

    2015-04-15

    Alkyl parabens are used as antimicrobial preservatives in cosmetics, food, and pharmaceutical products. However, the mode of action of these chemicals has not been assessed thoroughly. In this study, we determined the effects of alkyl parabens on plant pathogenic fungi. All the fungi tested, were susceptible to parabens. The effect of linear alkyl parabens on plant pathogenic fungi was related to the length of the alkyl chain. In addition, the antifungal activity was correlated with the paraben-induced inhibition of oxygen consumption. The antifungal activity of linear alkyl parabens likely originates, at least in part, from their ability to inhibit the membrane respiratory chain, especially mitochondrial complex II. Additionally, we determined that some alkyl parabens inhibit Alternaria brassicicola infection of cabbage.

  16. Alkylation damage by lipid electrophiles targets functional protein systems.

    PubMed

    Codreanu, Simona G; Ullery, Jody C; Zhu, Jing; Tallman, Keri A; Beavers, William N; Porter, Ned A; Marnett, Lawrence J; Zhang, Bing; Liebler, Daniel C

    2014-03-01

    Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells treated with lipid electrophile probes. Protein target profiles revealed three damage susceptibility classes, as well as proteins that were highly resistant to alkylation. Damage occurred selectively across functional protein interaction networks, with the most highly alkylation-susceptible proteins mapping to networks involved in cytoskeletal regulation. Proteins with lower damage susceptibility mapped to networks involved in protein synthesis and turnover and were alkylated only at electrophile concentrations that caused significant toxicity. Hierarchical susceptibility of proteome systems to alkylation may allow cells to survive sublethal damage while protecting critical cell functions.

  17. Transcription Factor OsDOF18 Controls Ammonium Uptake by Inducing Ammonium Transporters in Rice Roots

    PubMed Central

    Wu, Yunfei; Yang, Wenzhu; Wei, Jinhuan; Yoon, Hyeryung; An, Gynheung

    2017-01-01

    Nitrogen is one of the most important mineral elements for plant growth. We studied the functional roles of Oryza sativa DNA BINDING WITH ONE FINGER 18 (OsDOF18) in controlling ammonium uptake. The growth of null mutants of OsDOF18 was retarded in a medium containing ammonium as the sole nitrogen source. In contrast, those mutants grew normally in a medium with nitrate as the sole nitrogen source. The gene expression was induced by ammonium but not by nitrate. Uptake of ammonium was lower in osdof18 mutants than in the wild type, while that of nitrate was not affected by the mutation. This indicated that OsDOF18 is involved in regulating ammonium transport. Among the 10 ammonium transporter genes examined here, expression of OsAMT1;1, OsAMT1;3, OsAMT2;1, and OsAMT4;1 was reduced in osdof18 mutants, demonstrating that the ammonium transporter genes function downstream of OsDOF18. Genes for nitrogen assimilation were also affected in the mutants. These results provide evidence that OsDOF18 mediates ammonium transport and nitrogen distribution, which then affects nitrogen use efficiency. PMID:28292004

  18. Lithium perchlorate-nitromethane-promoted alkylation of anilines with arylmethanols.

    PubMed

    Zhou, Jun; Mao, Hai-Feng; Wang, Lu; Zou, Jian-Ping; Zhang, Wei

    2011-11-01

    A new application of lithium perchlorate-nitromethane (LPNM) for the formation of aromatic C-N and C-C bonds is introduced. LPNM-promoted reactions of anilines with diarylmethanols selectively generate N-alkylated anilines or mono and double Friedel-Crafts alkylation products under different conditions by changing the reaction time, reaction temperature, and the ratio of the reactants. This method does not require the use of transition metal catalysts to prepare alkylated aniline derivatives.

  19. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1999-03-01

    A leak to the atmosphere in the hydraulic end cone of a horizontal contactor and the realization that basic corrosion data are not available for high-throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in the horizontal contractor of an alkylation unit was mitigated successfully by saturating fresh alkylation acid with ferrous sulfate (FeSO{sub 4}).

  20. Photochemical Production of Alkyl Nitrates in the Tropical Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Dahl, E. E.; Yvon-Lewis, S. A.; Saltzman, E. S.

    2005-12-01

    Alkyl nitrates are important to the tropospheric NOx/ozone cycle because they represent a significant fraction of the reactive nitrogen (NOy). Previous work has shown that there is an oceanic source of alkyl nitrates. A photochemical mechanism for the formation of alkyl nitrates in seawater has been proposed. This mechanism involves the reaction of ROO and NO, where ROO is an alkyl peroxy radical. ROO and NO radicals in seawater are derived from the photolysis of DOM and nitrite, respectively. In this study, the photochemical production of low molecular weight alkyl nitrates (C1-C3) was observed in shipboard incubation experiments in the tropical Pacific during the PHASE 1 cruise. Seawater samples from several regions, including high and low-chlorophyll areas, were collected and incubated. Alkyl nitrate production rates as high as 2 nM/hour were observed. The production rate of alkyl nitrates was clearly dependent upon the initial concentration of nitrite, most likely as the source for NO radicals. While the magnitude of production varied between sample locations, the ratios of the production rates of the various alkyl nitrates remained relatively constant. The observed production ratios of methyl, ethyl, isopropyl, and n-propyl nitrate were 5.9:1.0:0.1:0.2. These ratios presumably reflect the speciation of peroxy radicals formed in seawater, and the yield of alkyl nitrates from the ROO+NO reaction. The observed production rate ratios are similar to the concentration ratios of alkyl nitrates observed in ambient seawater and the overlying atmosphere during the study. A comparison of the measured production rates and the observed concentrations, suggests that photochemically produced alkyl nitrates are a major source of atmospheric alkyl nitrates in the surface ocean and marine atmosphere.

  1. Nutrient release and ammonium sorption by poultry litter and wood biochars in stormwater treatment.

    PubMed

    Tian, Jing; Miller, Valentina; Chiu, Pei C; Maresca, Julia A; Guo, Mingxin; Imhoff, Paul T

    2016-05-15

    The feasibility of using biochar as a filter medium in stormwater treatment facilities was evaluated with a focus on ammonium retention. Successive batch extractions and batch ammonium sorption experiments were conducted in both deionized (DI) water and artificial stormwater using poultry litter (PL) and hardwood (HW) biochars pyrolyzed at 400°C and 500°C. No measureable nitrogen leached from HW biochars except 0.07 μmol/g of org-N from 400°C HW biochar. PL biochar pyrolyzed at 400°C leached 120-127 μmol/g of nitrogen but only 7.1-8.6 μmol/g of nitrogen when pyrolyzed at 500°C. Ammonium sorption was significant for all biochars. At a typical ammonium concentration of 2mg/L in stormwater, the maximum sorption was 150 mg/kg for PL biochar pryolyzed at 400°C. In stormwater, ion competition (e.g. Ca(2+)) suppressed ammonium sorption compared to DI water. Surprisingly, ammonium sorption was negatively correlated to the BET surface area of the tested biochars, but increased linearly with cation exchange capacity. Cation exchange capacity was the primary mechanism controlling ammonium sorption and was enhanced by pyrolysis at 400°C, while BET surface area was enhanced by pyrolysis at 500°C. The optimal properties (BET surface area, CEC, etc.) of biochar as a sorbent are not fixed but depend on the target pollutant. Stormwater infiltration column experiments in sand with 10% biochar removed over 90% of ammonium with influent ammonium concentration of 2mg/L, compared to only 1.7% removal in a sand-only column, indicating that kinetic limitations on sorption were minor for the storm conditions studied. Hardwood and poultry litter biochar pyrolyzed at 500°C and presumably higher temperature may be viable filter media for stormwater treatment facilities, as they showed limited release of organic and inorganic nutrients and acceptable ammonium sorption.

  2. Alkaline Phosphatase Revisited:  Hydrolysis of Alkyl Phosphates (†).

    PubMed

    O'Brien, Patrick J; Herschlag, Daniel

    2002-03-05

    Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion catalyst with two divalent zinc ions bound ∼4 Å apart in the active site. Studies spanning half a century have elucidated many structural and mechanistic features of this enzyme, rendering it an attractive model for investigating the potent catalytic power of bimetallic centers. Unfortunately, fundamental mechanistic features have been obscured by limitations with the standard assays. These assays generate concentrations of inorganic phosphate (Pi) in excess of its inhibition constant (K i ≈ 1 μM). This tight binding by Pi has affected the majority of published kinetic constants. Furthermore, binding limits k cat/K m for reaction of p-nitrophenyl phosphate, the most commonly employed substrate. We describe a sensitive (32)P-based assay for hydrolysis of alkyl phosphates that avoids the complication of product inhibition. We have revisited basic mechanistic features of AP with these alkyl phosphate substrates. The results suggest that the chemical step for phosphorylation of the enzyme limits k cat/K m. The pH-rate profile and additional results suggest that the serine nucleophile is active in its anionic form and has a pK a of ≤5.5 in the free enzyme. An inactivating pK a of 8.0 is observed for binding of both substrates and inhibitors, and we suggest that this corresponds to ionization of a zinc-coordinated water molecule. Counter to previous suggestions, inorganic phosphate dianion appears to bind to the highly charged AP active site at least as strongly as the trianion. The dependence of k cat/K m on the pK a of the leaving group follows a Brønsted correlation with a slope of βlg = -0.85 ± 0.1, differing substantially from the previously reported value of -0.2 obtained from data with a less sensitive assay. This steep leaving group dependence is consistent with a largely dissociative transition state for AP-catalyzed hydrolysis of phosphate monoesters. The new (32)P

  3. Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions

    NASA Astrophysics Data System (ADS)

    Tae-Joon, Kim; Kyung-Chai, Jeong; Jin-Ho, Park; In-Soon, Chang; Cheong-Song, Choi

    1994-05-01

    Ammonium carbonate solutions with an excessive amount of NH 3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO 32- and mole ratio of {NH 4+}/{CO 32-} in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution on the agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO 2 powders. Finally, the feasibility of manufacturing UO 2 fuel with a sintered pellet density of 10.52 g/cm 3, using the AUC powders generated in this experiment, was demonstrated.

  4. Calcium sulphate in ammonium sulphate solution

    USGS Publications Warehouse

    Sullivan, E.C.

    1905-01-01

    Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

  5. Characteristics of simultaneous ammonium and phosphate adsorption from hydrolysis urine onto natural loess.

    PubMed

    Jiang, Shanqing; Wang, Xiaochang; Yang, Shengjiong; Shi, Honglei

    2016-02-01

    Nutrient recovery from human urine is a promising pretreatment of domestic wastewater and provides a sustainable recyclability of N and P. In this study, batch experiments were conducted to identify the characteristics of natural loess (NL) for the adsorption and recovery of ammonium and phosphate from hydrolysis urine (HU). The adsorption mechanisms, the adsorption kinetics and isotherms, as well as the major influencing factors, such as pH and temperature, were investigated. Results revealed that adsorption of ammonium occurred by means of ion exchange and molecule adsorption with the ≡ Si-OH groups, while phosphate adsorption was based on the calcium phosphate precipitation reaction and formation of inner-sphere complexes with ≡ M-OH groups. The adsorption processes of ammonium and phosphate were well described by the pseudo-second-order kinetic model and the Freundlich isotherm model. Adsorption of phosphate was endothermic, while ammonium adsorption was exothermic. Furthermore, the maximum ammonium and phosphate adsorption capacities of NL was 23.24 mg N g(-1) and 4.01 mg P g(-1) at an initial pH of 9 and 10, respectively. Results demonstrated that nutrient-adsorbed NL used as compound fertilizer or conventional fertilizer superaddition was feasible for its high contents of N and P as well as its environmental friendliness.

  6. Understanding the impact of the central atom on the ionic liquid behavior: Phosphonium vs ammonium cations

    SciTech Connect

    Carvalho, Pedro J.; Ventura, Sónia P. M.; Batista, Marta L. S.; Schröder, Bernd; Coutinho, João A. P.; Gonçalves, Fernando; Esperança, José; Mutelet, Fabrice

    2014-02-14

    The influence of the cation's central atom in the behavior of pairs of ammonium- and phosphonium-based ionic liquids was investigated through the measurement of densities, viscosities, melting temperatures, activity coefficients at infinite dilution, refractive indices, and toxicity against Vibrio fischeri. All the properties investigated are affected by the cation's central atom nature, with ammonium-based ionic liquids presenting higher densities, viscosities, melting temperatures, and enthalpies. Activity coefficients at infinite dilution show the ammonium-based ionic liquids to present slightly higher infinite dilution activity coefficients for non-polar solvents, becoming slightly lower for polar solvents, suggesting that the ammonium-based ionic liquids present somewhat higher polarities. In good agreement these compounds present lower toxicities than the phosphonium congeners. To explain this behavior quantum chemical gas phase DFT calculations were performed on isolated ion pairs at the BP-TZVP level of theory. Electronic density results were used to derive electrostatic potentials of the identified minimum conformers. Electrostatic potential-derived CHelpG and Natural Population Analysis charges show the P atom of the tetraalkylphosphonium-based ionic liquids cation to be more positively charged than the N atom in the tetraalkylammonium-based analogous IL cation, and a noticeable charge delocalization occurring in the tetraalkylammonium cation, when compared with the respective phosphonium congener. It is argued that this charge delocalization is responsible for the enhanced polarity observed on the ammonium based ionic liquids explaining the changes in the thermophysical properties observed.

  7. A single-cell view of ammonium assimilation in coral-dinoflagellate symbiosis.

    PubMed

    Pernice, Mathieu; Meibom, Anders; Van Den Heuvel, Annamieke; Kopp, Christophe; Domart-Coulon, Isabelle; Hoegh-Guldberg, Ove; Dove, Sophie

    2012-07-01

    Assimilation of inorganic nitrogen from nutrient-poor tropical seas is an essential challenge for the endosymbiosis between reef-building corals and dinoflagellates. Despite the clear evidence that reef-building corals can use ammonium as inorganic nitrogen source, the dynamics and precise roles of host and symbionts in this fundamental process remain unclear. Here, we combine high spatial resolution ion microprobe imaging (NanoSIMS) and pulse-chase isotopic labeling in order to track the dynamics of ammonium incorporation within the intact symbiosis between the reef-building coral Acropora aspera and its dinoflagellate symbionts. We demonstrate that both dinoflagellate and animal cells have the capacity to rapidly fix nitrogen from seawater enriched in ammonium (in less than one hour). Further, by establishing the relative strengths of the capability to assimilate nitrogen for each cell compartment, we infer that dinoflagellate symbionts can fix 14 to 23 times more nitrogen than their coral host cells in response to a sudden pulse of ammonium-enriched seawater. Given the importance of nitrogen in cell maintenance, growth and functioning, the capability to fix ammonium from seawater into the symbiotic system may be a key component of coral nutrition. Interestingly, this metabolic response appears to be triggered rapidly by episodic nitrogen availability. The methods and results presented in this study open up for the exploration of dynamics and spatial patterns associated with metabolic activities and nutritional interactions in a multitude of organisms that live in symbiotic relationships.

  8. Advanced regeneration and fixed-bed study of ammonium and potassium removal from anaerobic digested wastewater by natural zeolite.

    PubMed

    Guo, Xuejun; Zeng, Larry; Jin, Xin

    2013-05-01

    Highly efficient regeneration of natural zeolite was developed in conjunction with the removal of high concentrations of ammonia and potassium from the reverse osmosis effluent of anaerobic-digested wastewater by fixed-bed ion exchange. The elution and uptake behavior of ammonium and potassium in the fixed bed were studied. Both batch desorption tests and on-column regeneration were conducted to develop an optimum regeneration condition compatible with the wastewater requirements. The effectiveness of ammonium elution increased with increasing alkaline concentration. The increase of salt dose significantly enhanced the ammonium maximum in the elution solution. Complete ammonium elution was achieved in 6 bed volumes (BV) when the alkaline and salt concentrations were respectively 0.1 mol/L and 18.6 g/L at a flow rate of 2.5-3.0 BV/hr. Due to the higher affinity of potassium with natural clinoptilolite, complete potassium elution was not achieved in all cases.

  9. Alkyl Chlorides as Hydrogen Bond Acceptors

    SciTech Connect

    Nadas, Janos I; Vukovic, Sinisa; Hay, Benjamin

    2012-01-01

    To gain an understanding of the role of an alkyl chloride as a hydrogen bond acceptor, geometries and interaction energies were calculated at the MP2/aug-cc-pVDZ level of theory for complexes between ethyl chloride and representative hydrogen donor groups. The results establish that these donors, which include hydrogen cyanide, methanol, nitrobenzene, pyrrole, acetamide, and N-methylurea, form X-H {hor_ellipsis} Cl hydrogen bonds (X = C, N, O) of weak to moderate strength, with {Delta}E values ranging from -2.8 to -5.3 kcal/mol.

  10. Determination of reaction rate constants for alkylation of 4-(p-nitrobenzyl) pyridine by different alkylating agents.

    PubMed

    Walles, S A

    1980-02-01

    The rate constants have been determined for the reaction between some different alkylating agents and 4-(p-nitrobenzyl) pyridine (NBP) in methanol. These constants have been compared with those for alkylation of aniline in water. All the constants were lower in methanol than in water but in different degrees. The rate constants of the different alkylating agents have been calculated at a nucleophilic strength n=2. The genetic risk defined as the degree of alkylation of a nucleophile (n=2) is equivalent to the rate constant kn=2 and the target dose. The dependence of the genetic risk on the rate constant (kn=2) is discussed.

  11. Properties of nitrate, sulfate and ammonium in typical polluted atmospheric aerosols (PM 10) in Beijing

    NASA Astrophysics Data System (ADS)

    Kai, Zhang; Yuesi, Wang; Tianxue, Wen; Yousef, Meslmani; Frank, Murray

    2007-03-01

    To gain an understanding of the characteristics of nitrate, sulfate and ammonium in the urban atmosphere of Beijing, an experiment was conducted in October 2004, using a method involving the rapid collection of particles and analysis using an ion chromatography system. The study shows that the mean concentration of water soluble ions (WSI) increased during heavily polluted weather, and this change in the concentration of pollutants was related to the meteorological background. The concentration of nitrate, sulfate and ammonium increased 7.9, 4.1 and 5.4 times, respectively, during heavily polluted periods. The concentration of nitrate increased most among the WSI in PM 10. The diurnal variations of nitrate, sulfate and ammonium in more polluted periods were different from those in less polluted periods. The highest concentration of nitrate (NO 3-), sulfate (SO 42-), and ammonium (NH 4+) appeared at 19:00 during more polluted periods. In contrast, the highest concentrations of these compounds occurred at noon during less polluted periods. A correlation analysis showed that NO 3-, SO 42-, NH 4+, nitrogen oxides (NO x) and sulfur dioxide (SO 2) had significant positive correlations in more polluted periods. The transformation ratio from SO 2 and NO x to SO 42- and NO 3- was higher in more polluted than that in less polluted periods.

  12. On the evaporation of ammonium sulfate solution

    SciTech Connect

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  13. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  14. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  15. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  16. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  17. Radioiodination of Aryl-Alkyl Cyclic Sulfates

    PubMed Central

    Mushti, Chandra; Papisov, Mikhail I.

    2015-01-01

    Among the currently available positron emitters suitable for Positron Emission Tomography (PET), 124I has the longest physical half-life (4.2 days). The long half-life and well-investigated behavior of iodine in vivo makes 124I very attractive for pharmacological studies. In this communication, we describe a simple yet effective method for the synthesis of novel 124I labeled compounds intended for PET imaging of arylsulfatase activity in vivo. Arylsulfatases have important biological functions, and genetic deficiencies of such functions require pharmacological replacement, the efficacy of which must be properly and non-invasively evaluated. These enzymes, even though their natural substrates are mostly of aliphatic nature, hydrolyze phenolic sulfates to phenol and sulfuric acid. The availability of [124I]iodinated substrates is expected to provide a PET-based method for measuring their activity in vivo. The currently available methods of synthesis of iodinated arylsulfates usually require either introducing of a protected sulfate ester early in the synthesis or introduction of sulfate group at the end of synthesis in a separate step. The described method gives the desired product in one step from an aryl-alkyl cyclic sulfate. When treated with iodide, the source cyclic sulfate opens with substitution of iodide at the alkyl center and gives the desired arylsulfate monoester. PMID:23135631

  18. Microstructure of Hydrophobically Modified Alkyl Acrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Tian, Jun; Seery, Thomas A. P.; Ho, Derek L.; Weiss, R. A.

    2004-03-01

    Hydrophobically modified water-soluble acrylamide polymers have a variety of applications, including viscosity thickeners, microencapsulation, biosensors and controlled drug delivery systems. The microstructure of copolymer hydrogels of N,N-dimethylacrylamide (DMA) or N-isopropylacrylamide(NIPA) modified with 2-(N-ethylfluorooctanesulfonamido)ethyl acrylate, FOSA, was studied by small angle x-ray (SAXS) and neutron scattering (SANS). Swelling and DSC measurements showed that FOSA/NIPA gels exhibited a volume phase transition (VPT), but that FOSA/DMA gels did not. A modified interacting core-shell model was used to explain the SAXS and SANS data for both gels. The crosslink junctions of the gel consisted of nanophase-separated FOSA domains as the core surrounded by a water-poor layer of the alkyl acrylamide. These nanodomains were dispersed in a matrix of water-swollen alkyl acrylamide that had large scale heterogeneities. The average spherical core radius ranged from 1 to 3 nm and the average shell thickness ranged from 1 to 1.5 nm; the aggregation number ranged from 10 to 200.

  19. ESCHERICHIA COLI Gene Induction by Alkylation Treatment

    PubMed Central

    Volkert, Michael R.; Nguyen, Dinh C.; Beard, K. Christopher

    1986-01-01

    Searches for alkylation-inducible (aid) genes of Escherichia coli have been conducted by screening random fusions of the Mu-dl(ApR lac) phage for fusions showing increased β-galactosidase activity after treatment with methylating agents, but not after treatments with UV-irradiation. In this report we describe gene fusions that are specifically induced by alkylation treatments. Nine new mutants are described, and their properties are compared with the five mutants described previously. The total of 14 fusion mutants map at five distinct genetic loci. They can be further subdivided on the basis of their induction by methyl methanesulfonate (MMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). alkA, aidB and aidD are induced by both agents and appear to be regulated by ada. Neither aidC nor aidI is regulated by ada. Moreover, since aidC is induced only by MNNG and aidI is induced only by MMS, these two genes are likely to be individually regulated. Thus, there appear to be at least three different regulatory mechanisms controlling aid genes. PMID:3080354

  20. Escherichia coli gene induction by alkylation treatment.

    PubMed

    Volkert, M R; Nguyen, D C; Beard, K C

    1986-01-01

    Searches for alkylation-inducible (aid) genes of Escherichia coli have been conducted by screening random fusions of the Mu-dl(ApR lac) phage for fusions showing increased beta-galactosidase activity after treatment with methylating agents, but not after treatments with UV-irradiation. In this report we describe gene fusions that are specifically induced by alkylation treatments. Nine new mutants are described, and their properties are compared with the five mutants described previously. The total of 14 fusion mutants map at five distinct genetic loci. They can be further subdivided on the basis of their induction by methyl methanesulfonate (MMS) and N-methyl-N' -nitro-N-nitrosoguanidine (MNNG). alkA, aidB and aidD are induced by both agents and appear to be regulated by ada. Neither aidC nor aidI is regulated by ada. Moreover, since aidC is induced only by MNNG and aidI is induced only by MMS, these two genes are likely to be individually regulated. Thus, there appear to be at least three different regulatory mechanisms controlling aid genes.

  1. Partial Crystallinity in Alkyl Side Chain Polymers.

    NASA Astrophysics Data System (ADS)

    Sahni, Vasav; Prasad, Shishir; Villate, Johanna; Jiang, Zhang; Sinha, Sunil; Dhinojwala, Ali

    2009-03-01

    Surface freezing is the formation of a crystalline monolayer at the free surface of a melt at a temperature Ts, a few degrees above the bulk freezing temperature, Tb. This effect, i.e. Ts> Tb, common to many chain molecules, is in marked contrast with the surface melting effect, i.e. Ts<=Tb, shown by almost all other materials. Various theoretical and experimental studies have been done to characterize the monolayer formed when the surface freezes before the bulk. We have studied the structure of a novel crystalline surface monolayer on top of a disordered melt of the same material (poly(n-alkyl acrylate)s) using grazing incidence x-ray diffraction. The grazing incidence x-ray diffraction, surface tension, and bulk latent heat results show that there is partial side-chain crystallinity. Also, the surface tension results explain the trend of the difference between the surface order-to-disorder transition temperature and the bulk melting temperature (δT) as a function of side chain length. The behavior of the crystal length, crystal spacing and tilt with varying alkyl chain length and temperature was also studied.

  2. The photodissociation dynamics of alkyl radicals

    SciTech Connect

    Giegerich, Jens; Fischer, Ingo

    2015-01-28

    The photodisscociation dynamics of the alkyl radicals i-propyl (CH(CH{sub 3}){sub 2}) and t-butyl (C(CH{sub 3}){sub 3}) are investigated by H-atom photofragment imaging. While i-propyl is excited at 250 nm, the photodynamics of t-butyl are explored over a large energy range using excitation wavelengths between 347 nm and 233 nm. The results are compared to those obtained previously for ethyl, CH{sub 3}CH{sub 2}, and to those reported for t-butyl using 248 nm excitation. The translational energy (E{sub T}) distribution of the H-atom photofragments is bimodal and appears rather similar for all three radicals. The low E{sub T} part of the distribution shows an isotropic photofragment angular distribution, while the high E{sub T} part is associated with a considerable anisotropy. Thus, for t-butyl, two H-atom loss channels of roughly equal importance have been identified in addition to the CH{sub 3}-loss channel reported previously. A mechanism for the photodissociation of alkyl radicals is suggested that is based on interactions between Rydberg- and valence states.

  3. Understanding the differential nitrogen sensing mechanism in rice genotypes through expression analysis of high and low affinity ammonium transporter genes.

    PubMed

    Gaur, Vikram Singh; Singh, U S; Gupta, Atul K; Kumar, Anil

    2012-03-01

    Two rice genotypes, Kalanamak 3119 (KN3119) and Pusa Basmati 1(PB1) differing in their optimum nitrogen requirements (30 and 120 kg/ha, respectively) were undertaken to study the expression of both high and low affinity ammonium transporter genes responsible for ammonium uptake. Exposing the roots of the seedlings of both the genotypes to increasing (NH(4))(2)SO(4) concentrations revealed that all the three families of rice AMT genes are expressed, some of which get altered in a genotype and concentration specific manner. This indicates that individual ammonium transporter genes have defined contributions for ammonium uptake and plant growth. Interestingly, in response to increasing nitrogen concentrations, a root specific high affinity gene, AMT1;3, was repressed in the roots of KN3119 but not in PB1 indicating the existence of a differential ammonium sensing mechanism. This also indicates that not only AMT1;3 is involved not only in ammonium uptake but may also in ammonium sensing. Further, if it can differentiate and could be used as a biomarker for nitrogen responsiveness. Expression analysis of low affinity AMT genes showed that, both AMT2;1 and AMT2;2 have high levels of expression in both roots and shoots and in KN3119 are induced at low ammonium concentrations. Expressions of AMT3 family genes were higher shoots than in the roots indicating that these genes are probably involved in the translocation and distribution of ammonium ions in leaves. The expression of the only high affinity AMT gene, AMT1;1, along with six low affinity AMT genes in the shoots suggests that low affinity AMTs in the shoots leaves are involved in supporting AMT1;1 to carry out its activities/function efficiently.

  4. Preparation and characterization of new low melting ammonium-based ionic liquids with ether functionality

    NASA Astrophysics Data System (ADS)

    Kärnä, Minna; Lahtinen, Manu; Valkonen, Jussi

    2009-03-01

    Eighteen new and three previously known but insufficiently characterized RŔ 3N +A - and R 2Ŕ 2N +A - type ( R = 2-ethoxyethyl or 4-methoxybenzyl, Ŕ = methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, A = Br, BF 4 or PF 6) quaternary ammonium (QA) salts were synthesized and characterized by using 1H and 13C NMR techniques, mass spectroscopy and elemental analysis. The bromide salts were synthesized either by treating dimethyl formamide with an ether functionalized alkyl bromide in the presence of potassium carbonate or by treating a tertiary amine with an ether functionalized alkyl bromide. The QA tetrafluoroborates and hexafluorophosphates were synthesized by metathesis reaction between a prepared QA bromide and HBF 4 or KPF 6. The crystal structures of four compounds were determined by X-ray single crystal diffraction and powder diffraction was used to study the crystallinity of the solid compounds and to compare the structural similarities between the single crystals and the microcrystalline bulk form. Thermal properties of all compounds were studied by using TG/DTA and DSC methods. The anion exchange had a clear lowering effect on the melting points and enhanced the thermal stability of the BF4- and PF6- salts compared to the analogous bromides. Most of the compounds melted clearly below 100 °C, of which four are liquid at room temperature.

  5. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  6. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  7. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  8. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  9. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  10. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  11. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  13. Organocatalytic enantioselective indole alkylations of alpha,beta-unsaturated ketones.

    PubMed

    Chen, Wei; Du, Wei; Yue, Lei; Li, Rui; Wu, Yong; Ding, Li-Sheng; Chen, Ying-Chun

    2007-03-07

    The C3-selective enantioselective Michael-type Friedel-Crafts alkylations of indoles with nonchelating alpha,beta-unsaturated alkyl ketones, catalysed by a chiral primary amine derived from natural cinchonine, were investigated. The reactions, in the presence of 30 mol% catalyst, were smoothly conducted at 0 to -20 degrees C. Moderate to good ee (47-89%) has been achieved.

  14. An overview of the properties of fatty acid alkyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid alkyl esters of plant oils, especially in the form of methyl esters, have numerous applications with fuel use having received the most attention in recent times due to the potential high volume. Various properties imparted by neat fatty acid alkyl esters have been shown to influence fuel ...

  15. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  16. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  17. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  18. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  19. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  20. 40 CFR 721.10073 - Modified alkyl acrylamide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified alkyl acrylamide (generic... Specific Chemical Substances § 721.10073 Modified alkyl acrylamide (generic). (a) Chemical substance and... acrylamide (PMN P-05-536) is subject to reporting under this section for the significant new uses...