Sample records for quaternary ammonium chloride

  1. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Quaternary ammonium chloride combination. 172.165 ...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be...

  2. Characterization of Micelles of Quaternary Ammonium Surfactants as Reaction Media I: Dodeclytrimethylammonium Bromide and Chloride

    E-print Network

    Bales, Barney

    Characterization of Micelles of Quaternary Ammonium Surfactants as Reaction Media I (DTAB and DTAC) as reaction media. For DTAB, the aggregation numbers, N, and the quenching rate constant added salt. Both surfactants conform to the power law N ) N0(Caq/cmc0) where N0 is the aggregation

  3. Removal and inactivation of Cryptosporidium and microbial indicators by a quaternary ammonium chloride (QAC)-treated zeolite in pilot filters.

    PubMed

    Abbaszadegan, Morteza; Monteiro, Patricia; Ouwens, Rudolf N; Ryu, Hodon; Alum, Absar

    2006-01-01

    A set of pilot filters packed with Zeolite filter media treated with a quaternary ammonium chloride (QAC) were evaluated to verify the proof of concept of their combined antimicrobial capabilities. Escherichia coli was removed and inactivated the most (2.83 log), followed by MS-2 (2.75 log), Klebsiella terriena (2.21 log), PRD-1 (1.95 log), Chlorella vulgaris (1.92 log), and Cryptosporidium parvum oocysts (1.78 log). Especially, inactivation of C. parvum oocysts (1.19 log) was higher than physical removal (0.54 log). The data suggest that QAC-treated Zeolite in the pilot filters has microbial inactivation capabilities and may have useful applications in other types of filter media. PMID:16760096

  4. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  5. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting. (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  6. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  7. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  8. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  9. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Ammonium chloride (NH4 Cl, 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 separates out at elevated temperatures, and ammonium chloride is...

  10. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Ammonium chloride (NH4 Cl, 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 separates out at elevated temperatures, and ammonium chloride is...

  11. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Ammonium chloride (NH4 Cl, 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 separates out at elevated temperatures, and ammonium chloride is...

  12. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Ammonium chloride (NH4 Cl, 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 separates out at elevated temperatures, and ammonium chloride is...

  13. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Ammonium chloride (NH4 Cl, 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 separates out at elevated temperatures, and ammonium chloride is...

  14. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Quaternary ammonium salts (generic). 721.10511 Section 721...Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance...identified generically as quaternary ammonium salts (PMNs P-07-320,...

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

    PubMed

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

    2014-12-01

    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

  16. Effect of alkyl quaternary ammonium on processing discoloration of melt-intercalated PVC-montmorillonite composites

    Microsoft Academic Search

    Chaoying Wan; Yong Zhang; Yinxi Zhang

    2004-01-01

    The effects of alkyl quaternary ammonium on the processing thermal stability of poly (vinyl chloride)\\/alkyl quaternary ammonium modified montmorillonite (PVC\\/OMMT) composites were investigated. PVC\\/sodium montmorillonite (MMT) composites were prepared for comparison. The intercalated PVC\\/OMMT composites exhibited a non-terminal rheological behavior, and showed better mechanical properties and higher thermal degradation stability than the PVC\\/MMT composites. However, under identical melt processing conditions,

  17. Imparting durable antimicrobial properties to cotton fabrics using quaternary ammonium salts through 4-aminobenzenesulfonic acid–chloro–triazine adduct

    Microsoft Academic Search

    Young-A Son; Byung-Soon Kim; K. Ravikumar; Seung-Goo Lee

    2006-01-01

    A 4-aminobenzenesulfonic acid–chloro–triazine adduct was successfully synthesized in a laboratory scale and treated with cotton fabrics in order to increase the anionic sites and thereby % exhaustion of cationic compounds. Two Quaternary Ammonium Salts (QAS) was investigated namely, Cetylpyridinum chloride (CPC) and Benzyldimethylhexadecyl ammonium chloride (BDHAC) which are widely accepted as strong antimicrobial agents. The reaction mechanism involved in the

  18. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

  19. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

  20. QUATERNARY AMMONIUM SALT-ASSISTED ORGANIC REACTIONS IN WATER: ALKYLATION OF PHENOLS

    Microsoft Academic Search

    Jean Jacques Vanden Eynde; Isabelle Mailleux

    2001-01-01

    A series of quaternary ammonium salts has been tested as phase transfer agents to promote reactions between phenols and alkyl halides in an aqueous solution of sodium hydroxide in the absence oforganic solvent. Methyltrioctylammonium chloride emerges as the most effective catalyst.

  1. Antimicrobial Polymeric Materials with Quaternary Ammonium and Phosphonium Salts

    PubMed Central

    Xue, Yan; Xiao, Huining; Zhang, Yi

    2015-01-01

    Polymeric materials containing quaternary ammonium and/or phosphonium salts have been extensively studied and applied to a variety of antimicrobial-relevant areas. With various architectures, polymeric quaternary ammonium/phosphonium salts were prepared using different approaches, exhibiting different antimicrobial activities and potential applications. This review focuses on the state of the art of antimicrobial polymers with quaternary ammonium/phosphonium salts. In particular, it discusses the structure and synthesis method, mechanisms of antimicrobial action, and the comparison of antimicrobial performance between these two kinds of polymers. PMID:25667977

  2. Synthesis and anticoagulant activity of the quaternary ammonium chitosan sulfates.

    PubMed

    Fan, Lihong; Wu, Penghui; Zhang, Jinrong; Gao, Song; Wang, Libo; Li, Mingjia; Sha, Mingming; Xie, Weiguo; Nie, Min

    2012-01-01

    Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight. PMID:21996571

  3. Quaternary ammonium biocides: efficacy in application.

    PubMed

    Gerba, Charles P

    2015-01-01

    Quaternary ammonium compounds (QACs) are among the most commonly used disinfectants. There has been concern that their widespread use will lead to the development of resistant organisms, and it has been suggested that limits should be place on their use. While increases in tolerance to QACs have been observed, there is no clear evidence to support the development of resistance to QACs. Since efflux pumps are believe to account for at least some of the increased tolerance found in bacteria, there has been concern that this will enhance the resistance of bacteria to certain antibiotics. QACs are membrane-active agents interacting with the cytoplasmic membrane of bacteria and lipids of viruses. The wide variety of chemical structures possible has seen an evolution in their effectiveness and expansion of applications over the last century, including non-lipid-containing viruses (i.e., noroviruses). Selection of formulations and methods of application have been shown to affect the efficacy of QACs. While numerous laboratory studies on the efficacy of QACs are available, relatively few studies have been conducted to assess their efficacy in practice. Better standardized tests for assessing and defining the differences between increases in tolerance versus resistance are needed. The ecological dynamics of microbial communities where QACs are a main line of defense against exposure to pathogens need to be better understood in terms of sublethal doses and antibiotic resistance. PMID:25362069

  4. Ineffectiveness of a quaternary ammonium salt and povidone-iodine for the inactivation of Ascaris suum eggs.

    PubMed

    Labare, Michael P; Soohoo, Hilary; Kim, Dong; Tsoi, Key yan; Liotta, Janice L; Bowman, Dwight D

    2013-04-01

    Two commonly used disinfectants, a quaternary ammonium salt and povidone-iodine, were tested for effectiveness against unembryonated Ascaris suum eggs. The quaternary ammonium salt (alkyl dimethyl benzyl ammonium chloride) had no effect on the Ascaris eggs (10 minutes and 22°C) when compared with the controls in water with egg viabilities of 88.8% ± 3.3% and 86.9% ± 6.2%, respectively. An additional quaternary ammonium salt, 2.5% benzethonium chloride, also had no effect. Phenol (5%) and cresol (3%) completely inactivated the eggs. Povidone-iodine at 100%, 50%, 10%, and 1% had no effect on the eggs at exposures of 5, 15, 30, 60, or 120 minutes (22°C) compared with the water controls. PMID:23102984

  5. Microtitration of various anions with quaternary ammonium halides using solid-state electrodes

    SciTech Connect

    Selig, W.

    1980-01-01

    Many solid-state electrodes were found to respond as endpoint detectors in the potentiometric titration of large inorganic and organic anions with quaternary ammonium halides. The best response was obtained with the iodide and cyanide electrodes although practically any electrode can function as endpoint sensor. The titrants were hexadecylpyridinium chloride and hexadecyltrimethylammonium chloride; hexadecyltrimethylammonium bromide and Hyamine 1622 may also be used. Some inorganic anions thus titratable are perrhenate, persulfate, ferricyanide, hexafluorophosphate, and hexachloroplatinate. Examples of organic anions titratable are nitroform, tetraphenylborate, cyanotriphenylborate, picrate, long-chain sulfates and sulfonates, and some soaps. The reverse titration of quaternary ammonium halides vs dodecylsulfate is also feasible. Some titrations are feasible in a partially nonaqueous medium.

  6. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...CATEGORY Ammonium Chloride Production Subcategory § 415.240...description of the ammonium chloride production subcategory. The provisions...discharges resulting from the production of ammonium chloride by the...of anhydrous ammonia with hydrogen chloride gas and by the...

  7. Antimicrobial cotton containing N-halamine and quaternary ammonium groups by grafting copolymerization

    NASA Astrophysics Data System (ADS)

    Liu, Ying; Liu, Yin; Ren, Xuehong; Huang, T. S.

    2014-03-01

    The monomer (3-acrylamidopropyl)trimethylammonium chloride (APTMAC) was used to treat cotton fibers by grafting copolymerization. The grafted cotton fabrics were characterized by SEM image and FTIR spectra. The treated samples with quaternary ammonium groups could decrease 96.08% of Staphylococcus aureus and 48.74% of Escherichia coli O157:H7 within 30 min. After chlorination with dilute sodium hypochlorite, the treated cotton fabrics containing both N-halamine and quaternary ammonium groups effectively inactivated 100% (log reduction 5.82) of S. aureus and 100% (log reduction 6.26) of E. coli O157:H7 within 5 min of contact time. The grafting process of cotton fabric has small effect on the thermal stability and tensile strength, which favors the practical application. Compared to the traditional pad-dry-cure method to produce antibacterial materials, the radical grafting copolymerization method occurred in water without any organic solvents involved in the whole treatment.

  8. 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 ?m 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. PMID:20857956

  9. Quaternary ammonium polyethylenimine nanoparticles for treating bacterial contaminated water.

    PubMed

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

    2015-04-01

    This study highlights the potential application of antimicrobial quaternary ammonium nanomaterials for water disinfection. Quaternary ammonium polyethylenimine (QA-PEI) nanoparticles (NPs) were synthesized by polyethylenimine crosslinking and alkylation with octyl iodide followed by methyl iodide quaternization. Particles modified with octyldodecyl alkyl chains were also prepared and evaluated. The antimicrobial activity of QA-PEI NPs was studied after anchoring in non-leaching polymeric coatings and also in aqueous suspension. Particles at different loadings (w/w) were embedded in polyethylene vinyl acetate and polyethylene methacrylic acid coatings and tested for antimicrobial activity against four representative strains of bacteria in static and dynamic modes. Coatings embedded with fluorescent labelled particles tracked by Axioscope fluorescence microscope during the antimicrobial test indicates no particles leaching out. Coatings loaded with 5% w/w QA-PEI exhibited strong antibacterial activity. Aqueous suspension was tested and found effective for bacterial decontamination at 0.1ppm and maintains its activity for several weeks. PMID:25800358

  10. Sorption of Polymeric Quaternary Ammonium Compounds to Humic Acid

    Microsoft Academic Search

    Janet Cumming; Darryl William Hawker; Heather Chapman; Kerry Nugent

    2011-01-01

    Polymeric quaternary ammonium salts or polyquaterniums are used not only in the water and wastewater industry but also in\\u000a cosmetics. The former have been extensively studied with sorption to wastewater treatment plant (WWTP) biosolids an important\\u000a factor in their fate, mitigating release to the environment. Compounds of cosmetic origin have not received the same scrutiny\\u000a as those used in other

  11. Preparation of bis -quaternary ammonium salts from epichlorohydrin

    Microsoft Academic Search

    Tae-Seong Kim; Toshikazu Hirao; Isao Ikeda

    1996-01-01

    A novelbis-quaternary ammonium salt was prepared conveniently and almost quantitatively fromN,N-dimethyldodecylamine, its hydrochloride, and epichlorohydrin. Reaction ofN,N-dimethyldodecylamine with epichlorohydrin (in the presence of the amine hydrochloride) or various dichloro compounds was\\u000a investigated by using1H nuclear magnetic resonance. The reaction route was studied by examining the reactivity of reagents with the amine and the\\u000a effect of reaction temperature. The ease of

  12. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Modified polymer of vinyl acetate and quaternary ammonium...Chemical Substances § 721.8658 Modified polymer of vinyl acetate and quaternary ammonium...substance identified generically as modified polymer of vinyl acetate and quaternary...

  13. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Modified polymer of vinyl acetate and quaternary ammonium...Chemical Substances § 721.8658 Modified polymer of vinyl acetate and quaternary ammonium...substance identified generically as modified polymer of vinyl acetate and quaternary...

  14. Formation of gas-phase clusters monitored during electrospray mass spectrometry: a study of quaternary ammonium pesticides.

    PubMed

    Evans, C S; Startin, J R; Goodall, D M; Keely, B J

    2001-01-01

    Gas-phase cluster formation between the quaternary ammonium pesticides paraquat, diquat, difenzoquat, chlormequat and mepiquat, and chloride and acetate anions present in a liquid chromatography (LC) mobile phase, has been studied using electrospray mass spectrometry. The clusters of paraquat, mepiquat and chlormequat were revealed over the entire m/z range of the mass spectrometer, and their formation is dependent on the concentrations of both the cationic and the anionic species. Mepiquat and chlormequat form clusters of the type [2M(q)(+) + A(-)](+), where M(q)(+) is the quaternary ammonium cation and A(-) is the anion. Paraquat forms a cluster species with ammonia and also an ion-pair complex with chloride anions. Diquat and difenzoquat did not form observable ion-pair complexes or clusters with any of the anions studied. Competitive binding of acetate and chloride anions reflects the higher charge density of chloride, which forms the dominant clusters with mepiquat and chlormequat. The formation of cluster species has implications for the quantification of quaternary ammonium pesticides and may have an influence on the linearity of calibrations. PMID:11466795

  15. Interaction of quaternary ammonium and phosphonium salts with photosynthetic membranes.

    PubMed

    Spiegel, S; Bader, K P

    2001-01-01

    Distinct concentration ranges of selected quaternary ammonium and phosphonium salts were elaborated to induce stimulatory or inhibitory effects, respectively, on photosynthetic reactions. By means of fluorescence induction measurements 3 different effects of alkylbenzyldimethylammonium chloride (ABDAC; zephirol) in chloroplast preparations from Pisum sativum were observed. 60 microM ABDAC produced a strong increase in Fmax with concurrently improved Kautsky kinetics. Increased ABDAC concentration (500 microM) led to a strong fluorescence quenching - virtually indistinguishable from the conditions following the addition of photosystem II electron acceptors like K3Fe[CN]6. Further increase of ABDAC to 5 mM provoked a drastic increase in the fluorescence yield together with the complete loss of any detectable kinetics. We suggest a 3-step interaction of ABDAC with the thylakoid membranes of photosynthetic organisms similar to our earlier discussion (Bader and Höper (1993), Z. Naturforsch. 49c, 87-94). We examined a series of derivatives with selectively modified side chains, central atoms and counter ions, respectively. Both an alkyl chain of the type ([-CH2-]n; n approximately > 10) and effective polar components are indispensable for the adsorption and intercalation of the molecule onto and into the thylakoid membranes. The benzyl group could be replaced by a methyl residue without any loss of effectiveness; replacement of the central nitrogen (N) by phosphorus (P) and the counter ion Cl by Br did not modify the effects and the results were indistinguishable from the ABDAC effect proper. Shortening of the alkyl chain to (-CH2-)6 resulted in a less effective interaction of e.g. tetraoctylammonium bromide with the photosynthetic membrane. Flash-induced oxygen evolution measurements with selected derivatives (15 microm) substantiated our interpretation of an improved OEC functioning by a substantial lowering of the miss parameter a and the exclusion of a chemical reduction as the standard S-state distribution was not affected. As evidenced by both SDS-PAGE and Western blot analyses the investigated molecules showed a direct interaction. The polypeptide patterns were characterized by a severe shift of the molecular weight components from high (20-67 kDa) to low (< 20 kDa) values. PMID:11837658

  16. Tandem mass spectrometric analysis of quaternary ammonium pesticides.

    PubMed

    Evans, C S; Startin, J R; Goodall, D M; Keely, B J

    2001-01-01

    A detailed MS(n) study on an ion trap instrument of the quaternary ammonium pesticides paraquat, diquat, difenzoquat, mepiquat and chlormequat reveals a number of ions not reported previously, and has allowed examination of the fragmentation pathways. A number of transitions that are highly specific to each quat have been identified. Optimal ion trap operating conditions determined using Simplex optimisation can promote either detection of a particular fragmentation transition or a range of MS/MS product ions with a high overall signal response. Thus, fragmentation conditions were optimised to enhance the specificity or sensitivity of MS/MS methods. PMID:11319792

  17. Action of ammonium on a chloride pump

    Microsoft Academic Search

    H. Meyer; H. D. Lux

    1974-01-01

    The actions of intra- and extracellularly applied ammonium ions were studied on membrane potentials of the isolated crayfish stretch receptor neuron. In accordance with results obtained from cat spinal motoneurons, ammonium produced a gradual and reversible shift of the IPSP reversal potential towards the resting potential following both kinds of application. In the concentrations tested extracellularly (3 to 15 mM\\/l),

  18. A Novel Route to Recognizing Quaternary Ammonium Cations Using Electrospray Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Shackman, Holly M.; Ding, Wei; Bolgar, Mark S.

    2015-01-01

    Characterizing and elucidating structures is a commonplace and necessary activity in the pharmaceutical industry with mass spectrometry and NMR being the primary tools for analysis. Although many functional groups are readily identifiable, quaternary ammonium cations have proven to be difficult to unequivocally identify using these techniques. Due to the lack of an N-H bond, quaternary ammonium groups can only be detected in the 1H NMR spectra by weak signals generated from long-range 14N-H coupling, which by themselves are inconclusive evidence of a quaternary ammonium functional group. Due to their low intensity, these signals are frequently not detected. Additionally, ions cannot be differentiated in a mass spectrum as an M+ or [M + H]+ ion without prior knowledge of the compound's structure. In order to utilize mass spectrometry as a tool for determining this functionality, ion cluster formation of quaternary ammonium cations and non-quaternary amines was studied using electrospray ionization. Several mobile phase modifiers were compared; however, the addition of small amounts of trifluoroacetic acid proved superior in producing characteristic and intense [M +2TFA]- clusters for compounds containing quaternary ammonium cations when using negative electrospray. By fragmenting this characteristic ion using CID, nearly all compounds studied could be unambiguously identified as containing a quaternary ammonium cation or a non-quaternary amine attributable to the presence (non-quaternary amine) or absence (quaternary ammonium cation) of the resulting [2TFA + H]- ion in the product spectra. This method of analysis provides a rapid, novel, and reliable technique for indicating the presence of quaternary ammonium cations in order to aid in structural elucidation.

  19. Simulation of the bis-(penicillamine) enkephalin in ammonium chloride solution: a comparison with sodium chloride.

    PubMed

    Marlow, Gail E; Pettitt, B Montgomery

    2003-02-01

    In order to quantify specific ion effects, a simulation study of bis(penicllamine) enkephalin, also known as DPDPE, has been performed in aqueous ammonium chloride solution and has been compared to a previous simulation of DPDPE in aqueous sodium chloride solution. Global thermodynamics have been calculated for a model system and the solution environment around DPDPE has been characterized. Associations of ions with DPDPE have been investigated. The observed differences between sodium chloride solution and ammonium chloride solution suggest that individual cations affect the solvation and peptide binding properties of a given anion. PMID:12548623

  20. 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 50-70nm 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. PMID:25686793

  1. Hydrogen bonding. Part 24. Dichotomous hydration behavior of quaternary ammonium halides

    NASA Astrophysics Data System (ADS)

    Harmon, Kenneth M.; Avci, Günsel F.; Thiel, Anne C.

    1987-10-01

    On dehydration in vacuo quaternary ammonium halides show two entirely different types of behavior. Type A salts give first a liquid (4-6 H 2O) of very low vapor pressure, then a series of crystalline framework clathrates (2-4 H 2O), then very stable monohydrates with water—anion dimeric clusters. Type B salts give first a hypobarogenic clathrate (solid at reduced pressure, liquid at 760 torr), then crystalline monohydrates, which, when the pressure is returned to 760 torr, disproportionate into anhydrous salt and same hypobarogenic clathrate. Liquid—solid equilibria for type A at 760 torr is always between framework clathrate and saturated solution (or possibly liquid clathrate) and for type B is between anhydrous salt and hypobarogenic clathrate. Dissolution in water is exothermic for type A salts and endothermic for type B. Examples: type A, choline fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride and chloride, tetrapropylammonium fluoride and chloride; type B, choline chloride, bromide, and iodide, tetramethylammonium chloride and bromide, tetraethylammonium bromide, tetrapropylammonium bromide. Type A behavior is favored by larger cation and smaller (more electronegative) anion, and type B by smaller cation and larger (less electronegative) anion.

  2. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520.310 Food and...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen...

  3. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520.310 Food and...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen...

  4. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520.310 Food and...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen...

  5. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520.310 Food and...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen...

  6. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520.310 Food and...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen...

  7. Formation and stabilization of anionic metal complexes in concentrated aqueous quaternary ammonium salt solutions

    SciTech Connect

    Aronson, F.L.; Hwang, L.L.Y.; Ronca, N.; Solomon, N.A.; Steigman, J.

    1985-02-04

    Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ammonium salts. Their UV spectra showed the well-resolved vibronic fine structure associated with the symmetric chromium-to-oxygen charge-transfer band. It is known that these progressions are resolved in aprotic solvents, but not in aqueous acidic solution alone, and that the loss of fine structure in aqueous media is due to hydrogen bonding. The stabilization of anionic metal complexes and the resolution of vibronic structure in halochromates are probably consequences of water-structure-enforced ion paring. The present work suggests that the water molecules in immediate contact with the complex anions are more strongly hydrogen bonded to each other than to the complex. 21 references, 4 figures.

  8. 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.

  9. Detection of Quaternary Ammonium Drugs in Equine Urine by Liquid Chromatography-Mass Spectrometry

    Microsoft Academic Search

    K. C. H. Yiu; E. N. M. Ho; T. S. M. Wan

    2004-01-01

    Quaternary ammonium drugs are anticholinergic agents and some of which have been known to be abused in equine sports. A general screening method for this class of drugs in equine urine by liquid chromatography-mass spectrometry (LC-MS) has not been reported. The paper describes an efficient LC-MS-MS method for the simultaneous detection and confirmation of twenty quaternary ammonium drugs at low

  10. Cellular uptake of polyurethane nanocarriers mediated by gemini quaternary ammonium.

    PubMed

    Ding, Mingming; He, Xueling; Wang, Zhigao; Li, Jiehua; Tan, Hong; Deng, Hua; Fu, Qiang; Gu, Qun

    2011-12-01

    The effective passage of drug formulations into tumor cells is a key factor in the development of nanoscale delivery systems. However, rapid cellular uptake with reduced toxicity remains a great challenge for efficient and safe delivery. In this study, we first use gemini quaternary ammonium (GQA) as a cell internalization promoter to enhance the cellular uptake of drug nanocarriers. It is found that a twenty times faster cell internalization could be achieved by introducing GQA into biodegradable multiblock polyurethane nanomicelles, as confirmed by flow cytometry and confocal laser scanning microscopy (CLSM) studies. Meanwhile, an added methoxyl-poly(ethylene glycol) (mPEG) outer corona could protect these cationic micelles from cytotoxicity at high concentrations, as verified by methyl tetrazolium (MTT) assay. Moreover, GQA not only acts as an enhancer for rapid cellular entry, but also plays an important role in controlled self-assembly and high drug loading capacity. Our work offers a new understanding on the role of cationic surfactants; and provides a facile and economical approach for the design of versatile drug nanocarriers to achieve efficient delivery and good biocompatibility. PMID:21907404

  11. 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

  12. Adaptation of Aquatic Microbial Communities to Quaternary Ammonium Compounds

    PubMed Central

    Ventullo, Roy M.; Larson, Robert J.

    1986-01-01

    The effects of long-chain (C12 to C18) quaternary ammonium compounds (QACs) on the density, heterotrophic activity, and biodegradation capabilities of heterotrophic bacteria were examined in situ in a lake ecosystem. Monoalkyl and dialkyl substituted QACs were tested over a range of concentrations (0.001 to 10 mg/liter) in both acute (3 h) and chronic (21 day) exposures. In general, none of the QACs tested had significant adverse effects on bacterial densities in either acute or chronic studies. However, significant decreases in bacterial heterotrophic activity were noted in acute studies at QAC concentrations from 0.1 to 10 mg/liter. Chronic exposure of lake microbial communities to a specific monoalkyl QAC resulted in an adaptive response and recovery of heterotrophic activity. No-observable-effect level in the adapted populations was >10 mg/liter. Chronic exposure also resulted in significant increases in the number and activity of bacteria capable of biodegrading the material. The increase in biodegradation capability was observed at low (microgram per liter) concentrations which are approximately the same as realistic environmental levels. In general, our studies indicated that exposure of lake microbial communities to QACs results in the development of adapted communities which are less sensitive to potential toxic effects and more active in the biodegradation of these materials. PMID:16346991

  13. Trospium chloride: an update on a quaternary anticholinergic for treatment of urge urinary incontinence

    PubMed Central

    Guay, David RP

    2005-01-01

    Trospium chloride is a quaternary ammonium compound, which is a competitive antagonist at muscarinic cholinergic receptors. Preclinical studies using porcine and human detrusor muscle strips demonstrated that trospium chloride was many-fold more potent than oxybutynin and tolterodine in inhibiting contractile responses to carbachol and electrical stimulation. The drug is poorly bioavailable orally (< 10%) and food reduces absorption by 70%– 80%. It is predominantly eliminated renally as unchanged compound. Trospium chloride, dosed 20 mg twice daily, is significantly superior to placebo in improving cystometric parameters, reducing urinary frequency, reducing incontinence episodes, and increasing urine volume per micturition. In active-controlled trials, trospium chloride was at least equivalent to immediate-release formulations of oxybutynin and tolterodine in efficacy and tolerability. The most problematic adverse effects of trospium chloride are the anticholinergic effects of dry mouth and constipation. Comparative efficacy/tolerability data with long-acting formulations of oxybutynin and tolterodine as well as other anticholinergics such as solifenacin and darifenacin are not available. On the basis of available data, trospium chloride does not appear to be a substantial advance upon existing anticholinergics in the management of urge urinary incontinence. PMID:18360555

  14. Analysis of polymeric quaternary ammonium salts as found in cosmetics by metachromatic polyelectrolyte titration

    Microsoft Academic Search

    J. L. Cumming; D. W. Hawker; C. Matthews; H. F. Chapman; K. Nugent

    2010-01-01

    Metachromatic polyelectrolyte titration was investigated as a means of analyzing polymeric quaternary ammonium salts (polyquaterniums) of relatively low charge density used as ingredients in cosmetics. They are of possible toxicological concern, but little is known of their environmental fate and behavior. With o-toluidine blue as the indicator, determination of the concentration of a range of polyquaterniums of commercial importance and

  15. Different Virucidal Activities of Hyperbranched Quaternary Ammonium Coatings on Poliovirus and Influenza Virus

    PubMed Central

    Tuladhar, Era; de Koning, Martijn C.; Fundeanu, Irina; Beumer, Rijkelt

    2012-01-01

    Virucidal activity of immobilized quaternary ammonium compounds (IQACs) coated onto glass and plastic surfaces was tested against enveloped influenza A (H1N1) virus and nonenveloped poliovirus Sabin1. The IQACs tested were virucidal against the influenza virus within 2 min, but no virucidal effect against poliovirus was found in 6 h. PMID:22287007

  16. Correlation of Pseudocholinesterase Inhibition and Plant Growth Retardation by Quaternary Ammonium Derivatives of (+)Limonene

    Microsoft Academic Search

    William F. Newhall

    1969-01-01

    THE terpene hydrocarbon (+)-limonene is widely distributed in nature and comprises more than 95 per cent of distilled citrus peel oils. As part of a study of limonene derivatives having possible biological activity, I reported the synthesis of a number of quaternary ammonium compounds which are plant growth retardants1,2. Several of these derivatives also inhibited human blood serum (pseudo) cholinesterase

  17. Synthesis of hierarchical zeolites using an inexpensive mono-quaternary ammonium surfactant as mesoporogen.

    PubMed

    Zhu, Xiaochun; Rohling, Roderigh; Filonenko, Georgy; Mezari, Brahim; Hofmann, Jan P; Asahina, Shunsuke; Hensen, Emiel J M

    2014-12-01

    A simple amphiphilic surfactant containing a mono-quaternary ammonium head group (N-methylpiperidine) is effective in imparting substantial mesoporosity during synthesis of SSZ-13 and ZSM-5 zeolites. Highly mesoporous SSZ-13 prepared in this manner shows greatly improved catalytic performance in the methanol-to-olefins reaction compared to bulk SSZ-13. PMID:25316609

  18. Comparing Effectiveness of Rhamnolipid Biosurfactant with a Quaternary Ammonium Salt Surfactant for Hydrate Anti-Agglomeration

    E-print Network

    Firoozabadi, Abbas

    Comparing Effectiveness of Rhamnolipid Biosurfactant with a Quaternary Ammonium Salt Surfactant through usage of polymers and surfactants, effective at 0.5-3 wt % of coproduced water. One group of low is on the use of two vastly different surfactants as anti-agglomerants. We use a model oil, water

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

    Microsoft Academic Search

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

    1995-01-01

    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

  20. Long-Term Ammonium Chloride or Sodium Bicarbonate Treatment in Two Models of Polycystic Kidney Disease

    Microsoft Academic Search

    Vicente E. Torres; Michael G. Branden; Izumi Yoshida; Vincent H. Gattone

    2001-01-01

    Administration of ammonium chloride aggravates, while short-term administration of sodium or potassium bicarbonate lessens the development of polycystic kidney disease in Han:SPRD rats. We have conducted studies to determine whether the protection afforded by the administration of sodium bicarbonate is sustained and prevents development of uremia during chronic administration and whether the effects of the administration of ammonium chloride and

  1. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    21 Food and Drugs 8 2012-04-01...ammonium chloride) (pDADMAC) additive. 878.4015 Section 878.4015 Food and Drugs FOOD AND DRUG ADMINISTRATION...ammonium chloride) (pDADMAC) additive. (a) Identification...

  2. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    21 Food and Drugs 8 2011-04-01...ammonium chloride) (pDADMAC) additive. 878.4015 Section 878.4015 Food and Drugs FOOD AND DRUG ADMINISTRATION...ammonium chloride) (pDADMAC) additive. (a) Identification...

  3. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    21 Food and Drugs 8 2013-04-01...ammonium chloride) (pDADMAC) additive. 878.4015 Section 878.4015 Food and Drugs FOOD AND DRUG ADMINISTRATION...ammonium chloride) (pDADMAC) additive. (a) Identification...

  4. New synthetic aliphatic sulfonamido-quaternary ammonium salts as anticancer chemotherapeutic agents.

    PubMed

    Song, Doona; Yang, Jee Sun; Oh, Changmok; Cui, Shuolin; Kim, Bo-Kyung; Won, Misun; Lee, Jang-ik; Kim, Hwan Mook; Han, Gyoonhee

    2013-11-01

    RhoB is expressed during tumor cell proliferation, survival, invasion, and metastasis. In malignant progression, the expression levels of RhoB are commonly attenuated. RhoB is known to be linked to the regulation of the PI3K/Akt survival pathways. Based on aliphatic amido-quaternary ammonium salts that induce apoptosis via up-regulation of RhoB, we synthesized novel aliphatic sulfonamido-quaternary ammonium salts. These new synthetic compounds were evaluated for their biological activities using an in vitro RhoB promoter assay in HeLa cells, and in a growth inhibition assay using human cancer cell lines including PC-3, NUGC-3, MDA-MB-231, ACHN, HCT-15, and NCI-H23. Compound 5b (ethyl-dimethyl-{3-[methyl-(tetradecane-1-sulfonyl)-amino]-propyl}-ammonium; iodide) was the most promising anticancer agent in the series, based upon the potency of growth inhibition and RhoB promotion. These new aliphatic sulfonamido-quaternary ammonium salts could be a valuable series for development of new anticancer chemotherapeutic agents. PMID:24095759

  5. Selective removal and inactivation of bacteria by nanoparticle composites prepared by surface modification of montmorillonite with quaternary ammonium compounds.

    PubMed

    Khalil, Rowaida K S

    2013-10-01

    The purpose of the present study was to prepare new nanocomposites with antibacterial activities by surface modification of montmorillonite using quaternary ammonium compounds that are widely applied as disinfectants and antiseptics in food-processing environments. The intercalation of four quaternary ammonium compounds namely benzalkonium chloride, cetylpyridinium chloride monohydrate, hexadecyltrimethylammonium bromide, tetraethylammonium chloride hydrate into montmorillonite layers was confirmed by X-ray diffraction. The antibacterial influences of the modified clay variants against important foodborne pathogens differed based on modifiers quantities, microbial cell densities, and length of contact. Elution experiments through 0.1 g of the studied montmorillonite variants indicated that Staphylococcus aureus, Pseudomonas aeroginosa, and Listeria monocytogenes were the most sensitive strains. 1 g of hexadecyltrimethylammonium bromide intercalated montmorillonites demonstrated maximum inactivation of L. monocytogenes populations, with 4.5 log c.f.u./ml units of reduction. In adsorption experiments, 0.1 g of tetraethylammonium chloride hydrate montmorillonite variants significantly reduced the growth of Escherichia coli O157:H7, L. monocytogenes, and S. aureus populations by 5.77, 6.33, and 7.38 log units respectively. Growth of wide variety of microorganisms was strongly inhibited to undetectable levels (chloride montmorillonite variants. This investigation highlights that reduction in counts of microbial populations adsorbed to the new nanocomposites was substantially different from that in elution experiments, where interactions of nanocomposites with bacteria were specific and more complex than simple ability to inactivate. Treatment columns packed with modified variants maintained their inactivation capacity to the growth of Salmonella Tennessee and S. aureus populations after 48 h of incubation at room temperature with maximum reductions of 6.3 and 5.0 log units respectively. New nanocomposites presented in this research may have potential applications in industrial scale for the control of foodborne pathogens by their incorporation into high-performance filters in food processing plant environments where selectivity in removal and/or inactivation of species in fluid flow streams is desirable. Nevertheless, extensive in vitro and in vivo studies of these new nanocomposites is essential to outpace the understanding of their potential impacts and consequences on human health and the environment if they will make an appearance in commercialized food packaging and containment food materials in the future. PMID:23709187

  6. New biocide with both N-chloramine and quaternary ammonium moieties exerts enhanced bactericidal activity.

    PubMed

    Li, Lingdong; Pu, Tianyun; Zhanel, George; Zhao, Nan; Ens, Werner; Liu, Song

    2012-09-01

    Considering the rise of antibiotic resistance, the development of new antibacterial agents with improved biocidal functions is urgently required. In this study, ionic 5,5-dimethylhydantoin (DMH) analogues containing either a quaternary ammonium moiety (2)-4) or a phosphonate functional group (5),-6), were designed and synthesized to investigate the possible enhancing effect of quaternary ammonium moieties on the antibacterial performance of N-chloramines. These ionic DMH analogues were converted to their N-chloramine counterparts either in free form or after being covalently immobilized on a polymer surface via the "click" chemistry method. In the subsequent antimicrobial assessment against multi-drug-resistant Escherichia coli (MDR-E. coli) and methicillin-resistant Staphylococcus aureus (MRSA), chlorinated 2 and 3, the cyclic N-chloramines with a structural cation, exhibited distinctly enhanced biocidal functions in solution and after immobilization on surfaces. PMID:23184796

  7. The Fate of Polymeric Quaternary Ammonium Salts from Cosmetics in Wastewater Treatment Plants

    Microsoft Academic Search

    Janet Cumming; Darryl Hawker; Heather Chapman; Kerry Nugent

    2011-01-01

    Polymeric quaternary ammonium salts or polyquaterniums used in cosmetics have been categorised as chemicals of concern in\\u000a wastewater treatment plant (WWTP) effluent largely on the basis of emerging evidence of toxicity to aquatic organisms. However,\\u000a little is known of their environmental fate and behaviour due to analytical difficulties with sample matrices. Their properties\\u000a of negligible volatilisation and biotransformation enable the

  8. Compatibility of quaternary ammonium-based ionic liquid electrolytes with electrodes in lithium ion batteries

    Microsoft Academic Search

    Honghe Zheng; Bao Li; Yanbao Fu; Takeshi Abe; Zempachi Ogumi

    2006-01-01

    Electrochemical intercalation\\/deintercalation behavior of lithium into\\/from electrodes of lithium ion batteries was comparatively investigated in 1mol\\/L LiClO4 ethylene carbonate–diethyl carbonate (EC-DEC) electrolyte and a quaternary ammonium-based ionic liquid electrolyte. The natural graphite anode exhibited satisfactory electrochemical performance in the ionic liquid electrolyte containing 20vol.% chloroethylenene carbonate (Cl-EC). This is attributed to the mild reduction of solvated Cl-EC molecules at the

  9. Effects of particle size and chain length on flotation of quaternary ammonium salts onto kaolinite

    NASA Astrophysics Data System (ADS)

    Longhua, Xu; Yuehua, Hu; Faqin, Dong; Hao, Jiang; Houqin, Wu; Zhen, Wang; Ruohua, Liu

    2014-05-01

    Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by flotation tests. Dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC) were used as collectors for kaolinite in different particle size fractions (0.075 ~ 0.01 mm, 0.045 ~ 0.075 mm, 0 ~ 0.045 mm). The anomalous flotation behavior of kaolinite have been further explained based on crystal structure considerations by adsorption tests and molecular dynamics (MD) simulation. The results show that the flotation recovery of kaolinite in all different particle size fractions decreases with an increase in pH. As the concentration of collectors increases, the flotation recovery increases. The longer the carbon chain of QAS is, the higher the recoveries of coarse kaolinite (0.075 ~ 0.01 mm and 0.045 ~ 0.075 mm) are. But the flotation recovery of the finest kaolinite (0 ~ 0.045 mm) decreases with chain lengths of QAS collectors increasing, which is consistent with the flotation results of unscreened kaolinite (0 ~ 0.075 mm). It is explained by the froth stability related to the residual concentration of QAS collector in mineral pulp. In lower residual concentration, the froth stability becomes worse. Within the range of flotation collector concentration, it's easy of CTAC to be completely adsorbed by kaolinite in the particle size fraction (0-0.045 mm), which led to lower flotation recovery. Moreover, it is interesting that the coarser particle size of kaolinite is, the higher flotation recovery is. The anomalous flotation behavior of kaolinite is rationalized based on crystal structure considerations. The results of MD simulations show that the (001) kaolinite surface has the strongest interaction with DTAC, compared with the (001) face, (010) and (110) edges. On the other hand, when particle size of kaolinite is altered, the number of basal planes and edge planes is changed. It is observed that the finer kaolinite particles size become, the greater relative surface area of edges and the more the number of edges are. It means that fine kaolinite particles have more edges to adsorb fewer cationic colletors than that of coarse kaolinite particles, which is responsible for the poorer floatability of fine kaolinite.

  10. Peptides derivatized with bicyclic quaternary ammonium ionization tags. Sequencing via tandem mass spectrometry.

    PubMed

    Setner, Bartosz; Rudowska, Magdalena; Klem, Ewelina; Cebrat, Marek; Szewczuk, Zbigniew

    2014-10-01

    Improving the sensitivity of detection and fragmentation of peptides to provide reliable sequencing of peptides is an important goal of mass spectrometric analysis. Peptides derivatized by bicyclic quaternary ammonium ionization tags: 1-azabicyclo[2.2.2]octane (ABCO) or 1,4-diazabicyclo[2.2.2]octane (DABCO), are characterized by an increased detection sensitivity in electrospray ionization mass spectrometry (ESI-MS) and longer retention times on the reverse-phase (RP) chromatography columns. The improvement of the detection limit was observed even for peptides dissolved in 10?mM NaCl. Collision-induced dissociation tandem mass spectrometry of quaternary ammonium salts derivatives of peptides showed dominant a- and b-type ions, allowing facile sequencing of peptides. The bicyclic ionization tags are stable in collision-induced dissociation experiments, and the resulted fragmentation pattern is not significantly influenced by either acidic or basic amino acid residues in the peptide sequence. Obtained results indicate the general usefulness of the bicyclic quaternary ammonium ionization tags for ESI-MS/MS sequencing of peptides. PMID:25303389

  11. TG comparison between the efficiency of deposited ammonium bromide and ammonium chloride on the flame-retardancy imparted to cotton fabric

    Microsoft Academic Search

    S. M. Mostashari; H. F. Moafi; S. Z. Mostashari

    2009-01-01

    This study investigates the effect of ammonium bromide and\\/or ammonium chloride as nondurable finishes on the flammability\\u000a of 100% cotton fabric, (woven construction, weighing 144 g m?2). The laundered bone-dried, weighed fabrics were impregnated with suitable concentrations of aqueous ammonium bromide and\\/or\\u000a ammonium chloride solutions by means of squeeze rolls and dried at 110°C for 30 min. Afterwards they were

  12. Evaluation of calcium chloride and ammonium thiosulfate as ammonia volatilization inhibitors for surface-applied urea

    E-print Network

    Sloan, John J.

    1989-01-01

    EVALUATION OF CALCIUM CHLORIDE AND AMMONIUM THIOSULFATE AS AMMONIA VOLATILIZATION INHIBITORS FOR SURFACE-APPLIED UREA A Thesis by JOHN J. SLOAN Submitted to the Office of Graduate Studies of Texas AgcM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1989 Ma!or Subject: Soil Science EVALUATION OF CALCIUM CHLORIDE AND AMMONIUM THIOSULFATE AS AMMONIA VOLATILIZATION INHIBITORS FOR SURFACE-APPLIED UREA A Thesis by JOHN J. SLOAN Approved as to style...

  13. Ammonium Chloride as a Flame Retardant in a Polyester Fabric and its Detection

    Microsoft Academic Search

    S. M. Mostashari; S. Z. Mostashari

    2008-01-01

    The effect of ammonium chloride as a nondurable finish on the flammability of 100% polyester fabric has been investigated. The laundered, bone-dried, weighed fabrics were impregnated with a suitable concentration of aqueous ammonium chloride solution by means of squeeze rolls and drying at 110°C for 30 min. They were then cooled in a desiccator, re-weighed in an analytical balance and kept

  14. Microbial Community Degradation of Widely Used Quaternary Ammonium Disinfectants

    PubMed Central

    Oh, Seungdae; Kurt, Zohre; Tsementzi, Despina; Weigand, Michael R.; Kim, Minjae; Hatt, Janet K.; Tandukar, Madan; Pavlostathis, Spyros G.; Spain, Jim C.

    2014-01-01

    Benzalkonium chlorides (BACs) are disinfectants widely used in a variety of clinical and environmental settings to prevent microbial infections, and they are frequently detected in nontarget environments, such as aquatic and engineered biological systems, even at toxic levels. Therefore, microbial degradation of BACs has important ramifications for alleviating disinfectant toxicity in nontarget environments as well as compromising disinfectant efficacy in target environments. However, how natural microbial communities respond to BAC exposure and what genes underlie BAC biodegradation remain elusive. Our previous metagenomic analysis of a river sediment microbial community revealed that BAC exposure selected for a low-diversity community, dominated by several members of the Pseudomonas genus that quickly degraded BACs. To elucidate the genetic determinants of BAC degradation, we conducted time-series metatranscriptomic analysis of this microbial community during a complete feeding cycle with BACs as the sole carbon and energy source under aerobic conditions. Metatranscriptomic profiles revealed a candidate gene for BAC dealkylation, the first step in BAC biodegradation that results in a product 500 times less toxic. Subsequent biochemical assays and isolate characterization verified that the putative amine oxidase gene product was functionally capable of initiating BAC degradation. Our analysis also revealed cooperative interactions among community members to alleviate BAC toxicity, such as the further degradation of BAC dealkylation by-products by organisms not encoding amine oxidase. Collectively, our results advance the understanding of BAC aerobic biodegradation and provide genetic biomarkers to assess the critical first step of this process in nontarget environments. PMID:24951783

  15. Microbial community degradation of widely used quaternary ammonium disinfectants.

    PubMed

    Oh, Seungdae; Kurt, Zohre; Tsementzi, Despina; Weigand, Michael R; Kim, Minjae; Hatt, Janet K; Tandukar, Madan; Pavlostathis, Spyros G; Spain, Jim C; Konstantinidis, Konstantinos T

    2014-10-01

    Benzalkonium chlorides (BACs) are disinfectants widely used in a variety of clinical and environmental settings to prevent microbial infections, and they are frequently detected in nontarget environments, such as aquatic and engineered biological systems, even at toxic levels. Therefore, microbial degradation of BACs has important ramifications for alleviating disinfectant toxicity in nontarget environments as well as compromising disinfectant efficacy in target environments. However, how natural microbial communities respond to BAC exposure and what genes underlie BAC biodegradation remain elusive. Our previous metagenomic analysis of a river sediment microbial community revealed that BAC exposure selected for a low-diversity community, dominated by several members of the Pseudomonas genus that quickly degraded BACs. To elucidate the genetic determinants of BAC degradation, we conducted time-series metatranscriptomic analysis of this microbial community during a complete feeding cycle with BACs as the sole carbon and energy source under aerobic conditions. Metatranscriptomic profiles revealed a candidate gene for BAC dealkylation, the first step in BAC biodegradation that results in a product 500 times less toxic. Subsequent biochemical assays and isolate characterization verified that the putative amine oxidase gene product was functionally capable of initiating BAC degradation. Our analysis also revealed cooperative interactions among community members to alleviate BAC toxicity, such as the further degradation of BAC dealkylation by-products by organisms not encoding amine oxidase. Collectively, our results advance the understanding of BAC aerobic biodegradation and provide genetic biomarkers to assess the critical first step of this process in nontarget environments. PMID:24951783

  16. Determination of residues of quaternary ammonium disinfectants in food products by liquid chromatography-tandem mass spectrometry.

    PubMed

    van Bruijnsvoort, Michel; Rooselaar, Joop; Stern, Alfred G; Jonker, Klaas M

    2004-01-01

    A liquid chromatography-tandem mass spectrometry method has been developed for the determination of residues of alkylbenzyldimethylammonium, didecyldimethylammonium, didodecyldimethylammonium, and benzyldodecylhydroxyethylammonium compounds in various food matrixes. These quaternary ammonium compounds (QAs) are used in the food industry as disinfectants. According to the Dutch Food Law, the total mass (expressed as cetyltrimethylammonium chloride) of QAs in food products shall not exceed the legislative limit of 0.5 mg/kg. Samples were extracted by a simple salting-out procedure, using acetonitrile and sodium chloride; about 100 samples could be prepared and analyzed daily. Special care had to be taken to thoroughly homogenize samples and to avoid the use of contaminated labware. The method was validated by a procedure in compliance with EU Directive 2002/657. From the matrixes of ice cream and minced meat, recoveries of more than 95% with a relative standard deviation of about 3% were obtained by 3 different analysts (n = 54). Detection limits were in the low microg/kg range. The decision limit (CCalpha) was determined to be 0.55 mg/kg. Dairy and meat products, collected in The Netherlands, were analyzed (761 samples). In 1% of the meat samples, 2% of the ice cream and milkshake samples, and 24% of the whipped cream samples, the Dutch legislative limit was exceeded. Over 2000 injections could be performed on a single column without deterioration of the peak shapes or recoveries. PMID:15295898

  17. Nickel-catalyzed amination of aryl chlorides with ammonia or ammonium salts.

    PubMed

    Green, Rebecca A; Hartwig, John F

    2015-03-16

    The nickel-catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well-defined single-component nickel(0) precatalyst containing a Josiphos ligand and an ?(2) -bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts. PMID:25711163

  18. Quaternary ammonium salts intercalated ?-ZrP compounds for adsorption of phenolic compounds

    NASA Astrophysics Data System (ADS)

    Wang, Hongning; Liu, Wenjin; Yao, Wei; Zhang, Ke; Zhong, Jing; Chen, Ruoyu

    2013-03-01

    By using methylamine as the colloidization agent to weaken the interactions of ?-ZrP laminate, the quaternary ammonium salts of DTAB, TTAB, CTAB and STAB were successfully intercalated into the methylamine pre-pillared ?-ZrP, denoted as DTAB-ZrP, TTAB-ZrP, CTAB-ZrP and STAB-ZrP, respectively. XRD, FTIR, TEM and N2 sorption were used to characterize the intercalated compounds, and the arrangements of intercalated quaternary ammonium salts within ZrP were supposed according to the results. It was shown that the interlayer distances were increased from 0.76 nm to 2.10-3.50 nm and the intercalated quaternary amine salt cationic bonded with Psbnd O- anion through electrostatic interaction. The phenolic compounds adsorption results have demonstrated that all the four intercalated compounds have good adsorption performance, and CTAB-ZrP show the highest maximum adsorption amounts of 0.90, 1.25 and 1.34 mmol g-1, for phenol, 2-chlorophenol and 2,4-dichlorophenolare, respectively. The adsorption isotherms of phenolic compounds are linear with the C0 of 2.0-6.0 mmol L-1 and fit well to both the Linear and the Freundlich models, which indicated that the adsorption mechanism is mainly partition effects of organic phase within ZrP interlayer.

  19. [Extinguishment of harmful algae by organo-clay modified by alkyl glucoside quaternary ammonium compound].

    PubMed

    Wu, Ping; Yu, Zhi-Ming; Song, Xiu-Xian

    2006-11-01

    Systematic study of the sorption behavior of alkyl glucoside quaternary ammonium compound (AGQAC) on kaolin and bentonite showed that the isotherms of its sorption can be described very well by the Langmuir isotherm. The rate of alkyl glucoside quaternary ammonium compound sorption on kaolin and bentonite was very fast, it could reach equilibration in one or two minutes, and its saturate sorption amount was much enough to be used to modify clays. Then the influence of alkyl glucoside quaternary ammonium compound on the growth of Prorocentrum donghaiense, Amphidinium carterae, Scrippsiella trochoidea were studied, it was found that when its concentration was below 0.4 mg/L, 0.5 mg/L, 0.8 mg/L it just restrained the growth of the algae, but when the concentration was above 0.6 mg/L, 0.75 mg/L, 1.2 mg/L it could cumber the algae's growth and even made them die after three days. When it was used combined with clays the concentration below 5 mg/L could enhance the algal removal efficiency of 50 mg/L clay from about 20% to above 90%, so it could decrease the concentration of crude clays in removing algal blooms. Meanwhile, the kinetics of red tide organism coagulation with clay was studied, the effects of different kinds and concentrations of clays, the second component added in clays were examined. Results showed that adding the second component in clay was the most efficient method to improve the algal removal efficiency. PMID:17326420

  20. Reversible phase transformation-type layer shape electrolyte based on POM and quaternary ammonium salt

    NASA Astrophysics Data System (ADS)

    Wu, Xuefei; Li, Yunyan; Wu, Qingyin; Ding, Hong; Yan, Wenfu

    2014-02-01

    A novel kind of organic-inorganic layer shape material, polyoxymetalates (POM)-type ionic liquid (IL) with Keggin structure and simple quaternary ammonium salt, (TOAMe)4PW11VO40 (trioctylmethylammonium = TOAMe,…) is synthesized and characterized by IR, UV, X-ray diffraction (XRD), TG-DTA. Its electrochemical property was investigated by cyclic voltammgram. Research results released the vanadium and the POM structure in the compound can process reduction in DMSO, which is unlikely in water solution as a simple hydrated ion because water will protonize substrate.

  1. Syntheses and Applications of (Thio)Urea-Containing Chiral Quaternary Ammonium Salt Catalysts

    PubMed Central

    Novacek, Johanna; Waser, Mario

    2014-01-01

    We herein report our efforts to obtain a new class of systematically modified bifunctional (thio)urea-containing quaternary ammonium salts based on easily obtainable chiral backbones. Among the different classes of catalysts that were successfully synthesized, those based on trans-1,2-cyclohexane diamine were found to be the most powerful for the asymmetric ?-fluorination of ?-keto esters. Selectivities up to 93:7 could be obtained by using only 2 mol-% of the optimized catalyst. The importance of the bifunctional nature of these catalysts was demonstrated by control experiments using simplified monofunctional catalyst analogues, which gave almost racemic product only. PMID:25339849

  2. Reduction of quaternary ammonium-induced ocular surface toxicity by emulsions: an in vivo study in rabbits

    PubMed Central

    Liang, H.; Brignole-Baudouin, F.; Rabinovich-Guilatt, L.; Mao, Z.; Riancho, L.; Faure, M.O.; Warnet, J.M.; Lambert, G.

    2008-01-01

    Purpose To evaluate and compare the toxicological profiles of two quaternary ammonium compounds (QAC), benzalkonium chloride (BAK), and cetalkonium chloride (CKC), in standard solution or cationic emulsion formulations in rabbit eyes using newly developed in vivo and ex vivo experimental approaches. Methods Seventy eyes of 35 adult male New Zealand albino rabbits were used in this study. They were randomly divided into five groups: 50 µl of phosphate-buffered saline (PBS), PBS containing 0.02% BAK or 0.002% CKC (BAK Sol and CKC Sol, respectively), and emulsion containing 0.02% BAK or 0.002% CKC (BAK Em and CKC Em, respectively) were applied to rabbit eyes 15 times at 5-min intervals. The ocular surface changes induced by these eye drops were investigated using slit-lamp examination, flow cytometry (FCM), impression cytology (IC) on conjunctiva, and corneal in vivo confocal microscopy (IVCM). Standard immunohistology in cryosections was also examined for cluster of differentiation (CD) 45+ infiltrating and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL)+ apoptotic cells. Results Clinical observations and IVCM showed that the highest toxicity was induced by BAK Sol, characterized by damaged corneal epithelium and a high level of inflammatory infiltration. BAK Em and CKC Sol presented moderate effects, and CKC Em showed the lowest toxicity with results similar to those of PBS. Conjunctival imprints analyzed by FCM showed a higher expression of RLA-DR and TNFR1 markers in BAK Sol-instilled eyes than in all other groups, especially at 4 h. Immunohistology was correlated with in vivo and ex vivo findings and confirmed this toxicity profile. A high level of infiltration of CD45+ inflammatory cells and TUNEL+ apoptotic cells was observed in limbus and conjunctiva, especially in QAC solution-receiving eyes compared to QAC emulsion-instilled eyes. Conclusions The acute administration of 15 instillations at 5 min intervals was a rapid and efficient model to assess quaternary ammonium toxicity profiles. This model showed the highest toxicity, induced by the BAK solution, and the lowest level of toxicity, induced by the CKC emulsion. These in vivo and ex vivo experimental approaches demonstrated that ocular surface toxicity was reduced by using an emulsion instead of a traditional solution and that a CKC emulsion was safe for future ocular administration. PMID:18347566

  3. Quaternary ammonium-type gemini surfactants synthesized from oleic acid: aqueous solution properties and adsorption characteristics.

    PubMed

    Sakai, Kenichi; Saito, Yuki; Uka, Akihito; Matsuda, Wataru; Takamatsu, Yuichiro; Kitiyanan, Boonyarach; Endo, Takeshi; Sakai, Hideki; Abe, Masahiko

    2013-01-01

    Cationic gemini surfactants having a quaternary ammonium headgroup have been synthesized from oleic acid. The hydrocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via an amide bond, while the quaternary ammonium headgroup is introduced onto the cis double bond of oleic acid. The Krafft temperature of these surfactants drops below room temperature (ca. 25°C) when the counterion is exchanged from Br? to Cl?. The aqueous solution properties of the Cl series of surfactants have been assessed by means of pyrene fluorescence, dynamic light scattering (DLS), and static surface tension measurements. An increased hydrocarbon chain length results in a lower critical micelle concentration (cmc) and a higher adsorption efficiency at the air/aqueous solution interface. Surface tension measurements suggest the formation of premicelles at concentrations below cmc, whereas, above cmc, DLS indicates the formation of micellar aggregates whose diameter ranges from 5 to 10 nm. We, furthermore, characterized the adsorption of these surfactants to the silica/aqueous solution interface and observed their spontaneous adsorption to the solid surface by electrostatic and intermolecular hydrophobic interactions. The combination of soft-contact imaging atomic force microscopy (AFM) and force-curve data suggests bilayer formation above cmc, which is reflective of the large packing parameter of the gemini surfactants. Interestingly, we found the repulsive interaction observed during compression of the adsorbed layer to be relatively weak, as a result of the low adsorption density and/or the loose molecular packing arrangement, which arises from the asymmetric structure. PMID:23823915

  4. Low-melting, low-viscous, hydrophobic ionic liquids: aliphatic quaternary ammonium salts with perfluoroalkyltrifluoroborates.

    PubMed

    Zhou, Zhi-Bin; Matsumoto, Hajime; Tatsumi, Kuniaki

    2005-01-01

    A novel class of low-melting, hydrophobic ionic liquids based on relatively small aliphatic quaternary ammonium cations ([R(1)R(2)R(3)NR](+), wherein R(1), R(2), R(3) = CH(3) or C(2)H(5), R = n-C(3)H(7), n-C(4)H(9), CH(2)CH(2)OCH(3)) and perfluoroalkyltrifluoroborate anions ([R(F)BF(3)](-), R(F) = CF(3), C(2)F(5), n-C(3)F(7), n-C(4)F(9)) have been prepared and characterized. The important physicochemical and electrochemical properties of these salts, including melting point, glass transition, viscosity, density, ionic conductivity, thermal and electrochemical stability, have been determined and comparatively studied with those based on the corresponding [BF(4)](-) and [(CF(3)SO(2))(2)N](-) salts. The influence of the structure variation in the quaternary ammonium cation and perfluoroalkyltrifluoroborate ([R(F)BF(3)](-)) anion on the above physicochemical properties is discussed. Most of these salts are liquids at 25 degrees C and exhibit low viscosities (58-210 cP at 25 degrees C) and moderate conductivities (1.1-3.8 mS cm(-1)). The electrochemical windows of these salts are much larger than those of the corresponding 1,3-dialkyimidazolium salts. Additionally, a number of [R(F)BF(3)](-) salts exhibit plastic crystal behavior. PMID:15584076

  5. Antibacterial activity of reactive quaternary ammonium compounds in solution and in nonleachable coatings.

    PubMed

    Gozzelino, G; Tobar, D E Romero; Chaitiemwong, N; Hazeleger, W; Beumer, R

    2011-12-01

    Antibacterial polymers suitable for coating applications without leaching of the biocidal component have been obtained by UV copolymerization of acrylic resins with acrylic monomers containing quaternary ammonium moieties. Suitable reactive biocides, based on quaternary ammonium monomers (QAMs), endowed with undecylacryloyl group and alkyl chains with 2 (QAM-C2), 8 (QAM-C8), and 16 (QAM-C16) carbon atoms have been synthesized. Aqueous solutions of QAMs showed biocidal activity against Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes strains both in suspension and adhered to stainless steel surfaces. QAM-C16 and QAM-C8 evidenced higher activity toward bacteria in suspension and on stainless steel, respectively. The QAMs have shown sufficient reactivity to be copolymerized, by UV irradiation, with a commercial urethane acrylic resin for coating. Bioactivity tests, performed on free films of crosslinked coatings containing 1% of copolymerized QAM, have shown an increasing inactivation effect in the order of magnitude L. monocytogenes, E. coli, S. aureus with a maximum activity of the QAM-C8. PMID:22186051

  6. The Listeria monocytogenes transposon Tn6188 provides increased tolerance to various quaternary ammonium compounds and ethidium bromide.

    PubMed

    Müller, Anneliese; Rychli, Kathrin; Zaiser, Andreas; Wieser, Cornelia; Wagner, Martin; Schmitz-Esser, Stephan

    2014-12-01

    Tolerance of the foodborne pathogen Listeria monocytogenes to sublethal concentrations of disinfectants has been frequently reported. Particularly, quaternary ammonium compounds (QACs) such as benzalkonium chloride (BC) are often used in disinfectants and also as antiseptics in food industry and hospitals. Recently, we described Tn6188, a novel transposon in L. monocytogenes harbouring the transporter QacH, a molecular mechanism leading to increased tolerance to BC. In this study, we investigated the presence of Tn6188 within the genus Listeria spp. Our screening indicates that the distribution of Tn6188 may be limited to L. monocytogenes. We confirm that QacH is responsible for the observed increase in tolerance by complementation of a qacH deletion mutant and introducing qacH in a Tn6188 negative strain. We investigated the transporter's substrate spectrum by determining minimal inhibitory concentrations (MICs) and showed that QacH also confers higher tolerance towards other QACs and ethidium bromide (EtBr). This result was supported by increased expression of qacH in the presence of the various substrates as determined by quantitative reverse transcriptase PCR (qRT-PCR). In addition, we detected expression of a Tn6188 transposase gene and circular forms of Tn6188, suggesting activity and possible transfer of this transposon. PMID:25312720

  7. Ion-exchange properties and electrochemical characterization of quaternary ammonium-functionalized silica microspheres obtained by the surfactant template route.

    PubMed

    Walcarius, Alain; Ganesan, Vellaichamy

    2006-01-01

    Porous silica spheres functionalized with quaternary ammonium groups have been prepared by co-condensation of N-((trimethoxysilyl)propyl)-N,N,N-trimethylammonium chloride (TMTMAC) and tetraethoxysilane (TEOS) in the presence of cetyltrimethylammonium as a template and ammonia as a catalyst. The physicochemical characteristics of the resulting ion exchangers have been analyzed by various techniques and discussed with respect to the amount of organofunctional groups in the materials. For comparison purposes, both an ordered MCM-41 type mesoporous silica and two silica gels of different pore size have been grafted with TMTMAC. The ion-exchange capabilities were first evaluated from batch experiments (determination of anion-exchange capacities) and then by ion-exchange voltammetry at carbon paste electrodes modified with these hybrid materials. Effective concentration of Fe(CN)(6)(3)(-) species in the anion exchangers was pointed out, while no significant accumulation of Ru(NH(3))(6)(3+) was observed. The preconcentration efficiency was discussed on the basis of the organic group content in the materials as well as their structure and porosity. A second series of materials displaying zwitterionic surfaces was finally prepared and characterized with respect to their physicochemical properties and ion-exchange voltammetric behavior. They consisted of sulfonic acid-functionalized mesoporous silica samples resulting from the oxidation of thiol-functionalized silica spheres obtained by co-condensation of mercaptopropyl-trimethoxysilane (MPTMS) and TEOS, which were then grafted with TMTMAC at various functionalization levels. Possible interactions between the ammonium and sulfonate moieties in the confined medium were pointed out from X-ray photoelectron spectroscopy. The competitive accumulation-rejection of Fe(CN)(6)(3)(-) and Ru(NH(3))(6)(3+) redox probes was finally studied by cyclic voltammetry. PMID:16378461

  8. Reporter-free potentiometric sensing of boronic acids and their reactions by using quaternary ammonium salt-functionalized polymeric liquid membranes.

    PubMed

    Wang, Xuewei; Yue, Dengfeng; Lv, Enguang; Wu, Lei; Qin, Wei

    2014-02-18

    The tremendous applications of boronic acids (BAs) in chemical sensing, medical chemistry, molecular assembly, and organic synthesis lead to an urgent demand for developing effective sensing methods for BAs. This paper reports a facile and sensitive potentiometric sensor scheme for heterogeneous detection of BAs based on their unexpected potential responses on quaternary ammonium salt-doped polymeric liquid membranes. (11)B NMR data reveal that a quaternary ammonium chloride can trigger the hydrolysis of an electrically neutral BA in an aprotic solvent. Using the quaternary ammonium salt as the receptor, the BA molecules can be extracted from the sample solution into the polymeric membrane phase and undergo the concomitant hydrolysis. Such salt-triggered hydrolysis generates H(+) ions, which can be coejected into the aqueous phase with the counterions (e.g., Cl(-)) owing to their high hydrophilicities. The perturbation on the ionic partition at the sample-membrane interface changes the phase boundary potential and thus enables the potentiometric sensing of BAs. In contrast to other transduction methods for BAs, for which labeled or separate reporters are exclusively required, the present heterogeneous sensing scheme allows the direct detection of BAs without using any reporter molecules. This technique shows superior detection limits for BAs (e.g., 1.0 × 10(-6) M for phenylboronic acid) as compared to previously reported methods based on colorimetry, fluorimetry, and mass spectrometry. The proposed sensing strategy has also been successfully applied to potentiometric indication of the BA reactions with hydrogen peroxide and saccharides, which allows indirect and sensitive detection of these important species. PMID:24484387

  9. An NMR study of quaternary ammonium salts of 5,7-dimethyl-1,3-diazaadamantan-6-one

    Microsoft Academic Search

    V. S. Semashko; S. Z. Vatsadze; N. V. Zyk; I. A. Godovikov

    2008-01-01

    The temperature dependence of the 1H NMR spectra of quaternary ammonium salts of 5,7-dimethyl-1,3-diazaadamantan-6-one in D2O was examined. The molar ratio of the ketone and hydrate forms was determined.

  10. Combined Hydrous Ferric Oxide and Quaternary Ammonium Surfactant Tailoring of Granular Activated Carbon for Concurrent Arsenate and Perchlorate Removal

    SciTech Connect

    Jang, M.; Cannon, F; Parette, R; Yoon, S; Chen, W

    2009-01-01

    Activated carbon was tailored with both iron and quaternary ammonium surfactants so as to concurrently remove both arsenate and perchlorate from groundwater. The iron (hydr)oxide preferentially removed the arsenate oxyanion but not perchlorate; while the quaternary ammonium preferentially removed the perchlorate oxyanion, but not the arsenate. The co-sorption of two anionic oxyanions via distinct mechanisms has yielded intriguing phenomena. Rapid small-scale column tests (RSSCTs) with these dually prepared media employed synthetic waters that were concurrently spiked with arsenate and perchlorate; and these trial results showed that the quaternary ammonium surfactants enhanced arsenate removal bed life by 25-50% when compared to activated carbon media that had been preloaded merely with iron (hydr)oxide; and the surfactant also enhanced the diffusion rate of arsenate per the Donnan effect. The authors also employed natural groundwater from Rutland, MA which contained 60 microg/L As and traces of silica, and sulfate; and the authors spiked this with 40 microg/L perchlorate. When processing this water, activated carbon that had been tailored with iron and cationic surfactant could treat 12,500 bed volumes before 10 microg/L arsenic breakthrough, and 4500 bed volumes before 6 microg/L perchlorate breakthrough. Although the quaternary ammonium surfactants exhibited only a slight capacity for removing arsenate, these surfactants did facilitate a more favorably positively charged avenue for the arsenate to diffuse through the media to the iron sorption site (i.e. via the Donnan effect).

  11. Enantioselective Michael reaction of malonates and chalcones by phase-transfer catalysis using chiral quaternary ammonium salt

    Microsoft Academic Search

    Dae Young Kim; Sun Chul Huh; Sung Min Kim

    2001-01-01

    The catalytic enantioselective Michael reaction promoted by quaternary ammonium salt from cinchonidine as a phase-transfer catalyst is described. Treatment of malonate with chalcone derivatives under mild reaction conditions afforded the corresponding Michael adducts in good yields with good to moderate enantiomeric excesses.

  12. Computational modeling of structure and OH-anion diffusion in quaternary ammonium polysulfone hydroxide Polymer electrolyte for application

    E-print Network

    Goddard III, William A.

    hydroxide ­ Polymer electrolyte for application in electrochemical devices Boris V. Merinov n , William A. Introduction Despite the significant progress made in reducing cost of Polymer Electrolyte Membrane Fuel Cells the microstructure of high-performance alkaline polymer, quaternary ammonium polysulfone hydroxide (QAPS

  13. High Levan Production by Bacillus licheniformis NS032 Using Ammonium Chloride as the Sole Nitrogen Source.

    PubMed

    Kekez, B D; Gojgic-Cvijovic, G D; Jakovljevic, D M; Stefanovic Kojic, J R; Markovic, M D; Beskoski, V P; Vrvic, M M

    2015-03-01

    In this study, levan production by Bacillus licheniformis NS032 isolated from a petroleum sludge sample was investigated. High levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/L) and, contrary to most levan-producing strains, using ammonium chloride as the sole N source. Interaction between sucrose, ammonium chloride, and initial pH of the medium in a low sucrose (60-200 g/L) and a high sucrose (300-400 g/L) system was analyzed by response surface methodology. According to the calculated model in the low sucrose system, maximum predicted levan yield was 47.8 g/L (sucrose 196.8 g/L, ammonium chloride 2.4 g/L, pH 7.0), while in the high sucrose system, levan yield was 99.2 g/L (sucrose 397.6 g/L, ammonium chloride 4.6 g/L, pH 7.4). In addition, protective effect of microbial levan against copper toxicity to Daphnia magna is observed for the first time. The acute toxicity (48 h EC50) of copper decreased from 0.14 to 0.44 mg/L by levan in concentration of 50 ppm. PMID:25592434

  14. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated nonwoven cotton substrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  15. Effect of cotton pectin content and bioscouring on alkyl-dimethyl-benzyl-ammonium chloride adsorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our previous research has shown both the rate and the total amount of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) exhausted from a bulk solution of ADBAC are significantly greater for greige cotton nonwovens than cotton nonwovens that have been both scoured and bleached. The presence of pectin ...

  16. Dietary ammonium chloride and the urinary excretion of chlortetracycline and oxytetracycline

    E-print Network

    Roberts, Ronald Curtis

    1967-01-01

    of MASTER OF SCIENCE August 1967 Ma)or Sub)cot; Animal Nutrition DIETARY AMMONIUM CHLORIDE AND THE URINARY EXCRETION OF CHLORTETRACYCLINE AND OXYTETRACYCLINE A Thesis by Ronald C. Roberts Approved as to style and content by: airma o ommi tee ea o...

  17. Biotreatment on cellulose fluff pulp: quaternary ammonium salts finish and grafting with beta-cyclodextrin.

    PubMed

    Ghemati, Djamila; Oudia, Atika; Aliouche, Djamel; Lamouri, Saad

    2009-11-01

    For its potential performances to be expanded, cellulose needs to be processed in different ways. Therefore, an object of the present work was to provide a chemical modification of cellulose through: a specific finish with two quaternary ammonium salts (namely Aliquat 336 and Aliquat 1529, respectively). Chemical grafting of beta-cyclodextrin derivative (beta-CD) onto fibers followed by the inclusion of benzoic acid in the grafted CD cavities as a probe chemical. Physicochemical properties and performances of the untreated and treated fibers have been determined with infrared spectra, microscopy, swelling measurements, antimicrobial finishing tests, and dye adsorption. Our results show that cellulose fibers can be efficiently modified with no significant changes in its structural and surface properties; the treated fibers show an attractive behavior in swelling, dye adsorption and antibacterial activity. PMID:19089647

  18. Low Temperature Double-Layer Capacitors Using Asymmetric and Spiro-Type Quaternary Ammonium Salts

    NASA Technical Reports Server (NTRS)

    Brandon, Erik J. (Inventor); Smart, Marshall C. (Inventor); West, William C. (Inventor)

    2014-01-01

    Double-layer capacitors capable of operating at extremely low temperatures (e.g., as low as -80.degree. C.) are disclosed. Electrolyte solutions combining a base solvent (e.g., acetonitrile) and a cosolvent are employed to lower the melting point of the base electrolyte. Example cosolvents include methyl formate, ethyl acetate, methyl acetate, propionitrile, butyronitrile, and 1,3-dioxolane. A quaternary ammonium salt including at least one of triethylmethylammonium tetrafluoroborate (TEMATFB) and spiro-(1,1')-bipyrrolidium tetrafluoroborate (SBPBF.sub.4), is used in an optimized concentration (e.g., 0.10 M to 0.75 M), dissolved into the electrolyte solution. Conventional device form factors and structural elements (e.g., porous carbon electrodes and a polyethylene separator) may be employed.

  19. Alkaline stability of quaternary ammonium cations for alkaline fuel cell membranes and ionic liquids.

    PubMed

    Marino, M G; Kreuer, K D

    2015-02-01

    The alkaline stability of 26 different quaternary ammonium groups (QA) is investigated for temperatures up to 160?°C and NaOH concentrations up to 10?mol?L(-1) with the aim to provide a basis for the selection of functional groups for hydroxide exchange membranes in alkaline fuel cells and of ionic-liquid cations stable in basic conditions. Most QAs exhibit unexpectedly high alkaline stability with the exception of aromatic cations. ?-Protons are found to be far less susceptible to nucleophilic attack than previously suggested, whereas the presence of benzyl groups, nearby hetero-atoms, or other electron-withdrawing species promote degradation reactions significantly. Cyclic QAs proved to be exceptionally stable, with the piperidine-based 6-azonia-spiro[5.5]undecane featuring the highest half-life at the chosen conditions. Absolute and relative stabilities presented herein stand in contrast to literature data, the differences being ascribed to solvent effects on degradation. PMID:25431246

  20. Biofilm-eradicating properties of quaternary ammonium amphiphiles: simple mimics of antimicrobial peptides.

    PubMed

    Jennings, Megan C; Ator, Laura E; Paniak, Thomas J; Minbiole, Kevin P C; Wuest, William M

    2014-10-13

    Bacterial biofilms are difficult to eradicate because of reduced antibiotic sensitivity and altered metabolic processes; thus, the development of new approaches to biofilm eradication is urgently needed. Antimicrobial peptides (AMPs) and quaternary ammonium cations (QACs) are distinct, yet well-known, classes of antibacterial compounds. By mapping the general regions of charge and hydrophobicity of QACs onto AMP structures, we designed a small library of QACs to serve as simple AMP mimics. In order to explore the role that cationic charge plays in biofilm eradication, structures were varied with respect to cationic character, distribution of charge, and alkyl side chain. The reported compounds possess minimum biofilm eradication concentrations (MBEC) as low as 25 ?M against Gram-positive biofilms, making them the most active anti-biofilm structures reported to date. These potent AMP mimics were synthesized in 1-2 steps and hint at the minimal structural requirements for biofilm destruction. PMID:25147134

  1. Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents

    SciTech Connect

    Maayan, Galia; Fish, Richard H.; Neumann, Ronny

    2003-05-28

    Perfluorinated quaternary ammonium cations, [CF{sub 3}(CF{sub 2}){sub 7}(CH{sub 2}){sub 3}]{sub 3}CH{sub 3}N{sup +} (RFN{sup +}), were synthesized and used as counter cations for the [WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW{sub 9}O{sub 34}){sub 2}]{sup 12-} (M = Mn(II), Zn(II)), polyoxometalate. The (RFN{sup +}){sub 12}[WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW9O{sub 34}){sub 2}] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected both by the hydrophobicity of the solvent and the substrate.

  2. Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

    PubMed Central

    Gong, Shi-qiang; Niu, Li-na; Kemp, Lisa K.; Yiu, Cynthia K.Y.; Ryou, Heonjune; Qi, Yi-pin; Blizzard, John D.; Nikonov, Sergey; Brackett, Martha G.; Messer, Regina L.W.; Wu, Christine D.; Mao, Jing; Brister, L. Bryan; Rueggeberg, Frederick A.; Arola, Dwayne D.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Design of antimicrobial polymers for enhancing healthcare issues and minimizing environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially-hydrolyzed QAMS copolymerized with bis-GMA is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. Kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix. PMID:22659173

  3. Ammonium Chloride and Ammonium Sulfate for Prevention of Parturient Paresis in Dairy Cows1

    Microsoft Academic Search

    G. R. Oetzel; J. D. Olson; C. R. Curtis; M. J. Fettman

    1988-01-01

    Forty-eight Holstein cows with two or more previous lactations and no history of parturient paresis were randomly assigned to one of four prepartum diets in a 2 x 2 factorial design to determine the effect of dietary supplementation with ammonium salts and Ca intake on serum Ca concentrations at calving. Four diets provided either 53 g total dietary Ca\\/d or

  4. Synthesis and characterization of dimethacrylates containing quaternary ammonium functionalities for dental applications

    PubMed Central

    Antonucci, Joseph M.; Zeiger, Diana N.; Tang, Kathy; Lin-Gibson, Sheng; Fowler, Bruce O.; Lin, Nancy J.

    2011-01-01

    Objectives The widespread incidence of recurrent caries highlights the need for improved dental restorative materials. The objective of this study was to synthesize low viscosity ionic dimethacrylate monomers (IDMAs) that contain quaternary ammoniums groups (antimicrobial functionalities) and are compatible with existing dental dimethacrylate-based monomers. Such monomers have the potential to copolymerize with other methacrylate monomers and produce antibacterial polymers. Methods Two monomers (IDMA-1 and IDMA-2) were synthesized using the Menschutkin reaction and incorporated at 0% to 30% (by mass) into a 1:1 (by mass) bisphenol A glycerolate dimethacrylate (BisGMA):triethylene glycol dimethacrylate (TEGDMA) resin. Resin viscosity was quantified using rheology, and polymer degree of conversion (DC) and surface charge density were measured using Fourier transform infrared spectroscopy (FTIR) and fluorescein binding, respectively. Effects of IDMA-1 on initial attachment of Streptococcus mutans and on viability and enzymatic activity (formazan reduction) of RAW 264.7 macrophage-like cells were quantified. Results IDMA-1 and IDMA-2 were prepared and characterized. IDMA-1 was miscible with BisGMA:TEGDMA and slightly increased the resin viscosity and DC. As expected, polymeric surface charge density increased with increasing IDMA-1. Incorporation of 10% IDMA-1 into BisGMA:TEGDMA reduced bacterial colonization without affecting viability or enzymatic activity of mammalian cells. Increasing IDMA-1 up to 30% had no additional effect on bacterial coverage, but ? 20% IDMA-1 significantly reduced macrophage density, viability, and enzymatic activity. Leachables from polymers containing IDMA-1 were not cytotoxic. Significance The Menschutkin reaction provides a facile, convenient means to synthesize new monomers with quaternary ammonium groups for dental and medical applications. PMID:22035983

  5. Dental primer and adhesive containing a new antibacterial quaternary ammonium monomer dimethylaminododecyl methacrylate

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Zhang, Ke; Arola, Dwayne D.; Zhou, Xuedong; Xu, Hockin H. K.

    2013-01-01

    Objectives The main reason for restoration failure is secondary caries caused by biofilm acids. Replacing the failed restorations accounts for 50–70% of all operative work. The objectives of this study were to incorporate a new quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM) and nanoparticles of silver (NAg) into a primer and an adhesive, and to investigate their effects on antibacterial and dentin bonding properties. Methods Scotchbond Multi-Purpose (SBMP) served as control. DMADDM was synthesized and incorporated with NAg into primer/adhesive. A dental plaque microcosm biofilm model with human saliva was used to investigate metabolic activity, colony-forming units (CFU), and lactic acid. Dentin shear bond strengths were measured. Results Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the new DMADDM were orders of magnitude lower than those of a previous quaternary ammonium dimethacrylate (QADM). Uncured primer with DMADDM had much larger inhibition zones than QADM (p<0.05). Cured primer/adhesive with DMADDM-NAg greatly reduced biofilm metabolic activity (p<0.05). Combining DMADDM with NAg in primer/adhesive resulted in less CFU than DMADDM alone (p<0.05). Lactic acid production by biofilms was reduced by 20-fold via DMADDM-NAg, compared to control. Incorporation of DMADDM and NAg into primer/adhesive did not adversely affect dentin bond strength. Conclusions A new antibacterial monomer DMADDM was synthesized and incorporated into primer/adhesive for the first time. The bonding agents are promising to combat residual bacteria in tooth cavity and invading bacteria at tooth-restoration margins to inhibit caries. DMADDM and NAg are promising for use into a wide range of dental adhesive systems and restoratives. PMID:23353068

  6. Supramolecular assembly of borate with quaternary ammonium: Crystal structure and tunable luminescent properties

    SciTech Connect

    Liang, Jie; Wang, Yong-gang [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Wang, Ying-xia, E-mail: wangyx@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Liao, Fu-hui [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Lin, Jian-hua, E-mail: jhlin@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2013-04-15

    A new borate [C{sub 6}H{sub 16}N][B{sub 5}O{sub 6}(OH){sub 4}] (1) is synthesized hydrothermally by the reaction of isopropyltrimethylammonium hydroxide with boric acid. It crystallizes in the triclinic space group P-1 with the parameters a=9.1578(10) Å, b=9.372(9) Å, c=9.9812(10) Å, ?=66.508(2)°, ?=74.751(2)°, ?=81.893(2)°. The [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions are interlinked via hydrogen bonding forming a 3D supramolecular network containing large cavities, where reside the (CH{sub 3}){sub 3}(i-C{sub 3}H{sub 7}) N{sup +} cations. This borate shows tunable luminescent properties with temperature, heating-treatment, exciting-light, and solvents. The fluorescent intensity of 1 enhances 6-fold with decreasing the temperature from 25 K to 78 K. By treatment under different temperatures, the luminescence of 1 shifted from blue to white and the sample treated at 230 °C emits bright white light to naked eyes. The hybrid borate can disperse in different solvents, and shows a red-shifted and intense emission in polar solvents. - Graphical abstract: The new quaternary ammonium borate [C{sub 6}H{sub 17}N][B{sub 5}O{sub 6}(OH){sub 4}] contains a 3D supramolecular network formed by hydrogen bond linked [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions and shows tunable luminescent properties with temperature, excitation light, and solvents. Highlights: ? A novel quaternary ammonium borate was synthesized. ? It possesses a supramolecular network fomed by H-bonded [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions. ? This borate shows tunable luminescent properties with temperature, heating treatment, excitation light, and solvents.

  7. Cationic curdlan: Synthesis, characterization and application of quaternary ammonium salts of curdlan.

    PubMed

    Suflet, Dana M; Popescu, Irina; Pelin, Irina M; Nicolescu, Alina; Hitruc, Gabriela

    2015-06-01

    Water-soluble curdlan derivatives containing quaternary ammonium groups with a degree of substitution up to 0.15 were synthesized using different cationic agents in alkaline medium. The chemical structure of curdlan derivatives was confirmed by FTIR, (13)C and (1)H NMR spectroscopy. The influence of some reaction conditions (temperature, time, and molar ratio) on the degree of substitution and the viscosimetic behaviour were studied. The degree of substitution increased with the amount of the cationization agent per anhydroglucose unit and was higher when the glycidyl reagents were used, compared with the case when the reagents contained chloro-hydroxypropyl groups. The viscosity behaviour of these new derivatives of curdlan in aqueous solutions and the values of intrinsic viscosities calculated using different semi-empirical equations denote a high hydrodynamic dimension of the macromolecular coils. The interaction of these cationic curdlan derivatives with an anionic curdlan (monobasic curdlan phosphate) was studied in situ by turbidimetric measurements and after 24h by optical density and dynamic light scattering. The formation of polyelectrolyte complexes was influenced by the degree of substitution, the nature of the quaternary substituent, and by the ionic strength of the aqueous solution. The morphology of the polyelectrolyte complexes particles in dry state was examined by atomic force microscopy. PMID:25843873

  8. Separation of the isomers of benzene poly(carboxylic acid)s by quaternary ammonium salt via formation of deep eutectic solvents.

    PubMed

    Hou, Yucui; Li, Jian; Ren, Shuhang; Niu, Muge; Wu, Weize

    2014-11-26

    Because of similar properties and very low volatility, isomers of benzene poly(carboxylic acid)s (BPCAs) are very difficult to separate. In this work, we found that isomers of BPCAs could be separated efficiently by quaternary ammonium salts (QASs) via formation of deep eutectic solvents (DESs). Three kinds of QASs were used to separate the isomers of BPCAs, including the isomers of benzene tricarboxylic acids (trimellitic acid, trimesic acid, and hemimellitic acid) and the isomers of benzene dicarboxylic acids (phthalic acid and isophthalic acid). Among the QASs, tetraethylammonium chloride was found to have the best performance, which could completely separate BPCA isomers in methyl ethyl ketone solutions. It was found that the hydrogen bond forming between QAS and BPCA results in the selective separation of BPCA isomers. QAS in DES was regenerated effectively by the antisolvent method, and the regenerated QAS was reused four times with the same high efficiency. PMID:25351281

  9. Experimental charge density evidence for pnicogen bonding in a crystal of ammonium chloride.

    PubMed

    Nelyubina, Yulia V; Korlyukov, Alexander A; Lyssenko, Konstantin A

    2015-02-23

    Chemical binding in crystalline ammonium chloride, a simple inorganic salt with an unexpectedly complex bonding pattern, was studied by using a topological analysis of electron density function derived from high-resolution X-ray diffraction. Supported by periodic quantum chemical calculations, it provided experimental evidence for weak ?-hole bonds (1.5 kcal?mol(-1) ) that involve ammonium cations in a crystal. Our results show this type of supramolecular interaction to be more numerous than has been found to date by using gas-phase calculations or statistical analysis of CSD. PMID:25521341

  10. Effect of Quaternary Ammonium Carboxymethylchitosan on Release Rate In-vitro of Aspirin Sustained-release Matrix Tablets.

    PubMed

    Meng, Lingbin; Teng, Zhongqiu; Zheng, Nannan; Meng, Weiwei; Dai, Rongji; Deng, Yulin

    2013-01-01

    The aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. A water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan (CMCTS), decylalkyl dimethyl ammonium and epichlorohydrin. The elemental analysis showed that the target product with 10.27% of the maximum grafting degree was obtained. To assess the preliminary safety of this biopolymer, cell toxicity assay was employed. In order to further investigate quaternary ammonium carboxymethylchitosan application as pharmaceutical excipient, aspirin was chosen as model drug. The effect of quaternary ammonium CMCTS on aspirin release rate from sustained-release matrix tablets was examined by in-vitro dissolution experiments. The results showed that this biopolymer had a great potential in increasing the dissolution of poorly soluble drug. With the addition of CMCTS-CEDA, the final cumulative release rate of drug rose up to 90%. After 12 h, at the grade of 10, 20 and 50 cps, the drug release rate increased from 58.1 to 90.7%, from 64.1 to 93.9%, from 69.3 to 96.1%, respectively. At the same time, aspirin release rate from sustainedrelease model was found to be related to the amount of quaternary ammonium CMCTS employed. With the increase of CMCTS-CEDA content, the accumulated release rate increased from 69.1% to 86.7%. The mechanism of aspirin release from sustained-release matrix tablets was also preliminary studied to be Fick diffusion. These data demonstrated that the chitosan derivative has positive effect on drug release from sustained-release matrix tablets. PMID:24250627

  11. Genetic linkage between resistance to quaternary ammonium compounds and beta-lactam antibiotics in food-related Staphylococcus spp.

    PubMed

    Sidhu, M S; Heir, E; Sørum, H; Holck, A

    2001-01-01

    Little is known about the occurrence of antimicrobial resistance determinants in staphylococci isolated from food and food processing industries. Quaternary ammonium compound (QAC)-resistant coagulase-negative staphylococci (CNS) isolated from food and food-processing industries were investigated for the presence of genetic determinants (qacA/B and qacC/smr) encoding resistance to the QAC benzalkonium chloride (BC), several antibiotic resistance genes, and staphylococcal insertion sequences IS257 and IS256. Six qacA/B-harboring strains were resistant to penicillin and hybridized to a blaZ probe. The qacA/B and blaZ probes hybridized to plasmids of similar size in three isolates. Molecular and genetic characterization of the 23-kb plasmid (pST6) of Staphylococcus epidermidis St.6 revealed the presence of qacB adjacent to an incomplete beta-lactamase transposon Tn552 encoding the gene cluster blaZ, blaR, and blaI. Sequence analysis of flanking regions and the intergenic region between blaZ and qacB revealed the presence of IS257 downstream of blaZ as well as sin and binR between blaZ and qacB. In the three other BC and penicillin-resistant strains, the qacA/B and blaZ genes were located on separate plasmids. A qacC harboring S. epidermidis strain (St.17) also hybridized to tetK (tetracycline resistance) and ermB (erythromycin resistance) genes. The individual genes were located on separate plasmids, suggesting no linkage between QAC and antibiotic resistance determinants. Plasmid-free Staphylococcus aureus RN4220 allowed uptake of the pST6 plasmid DNA, indicating that the resistance genes could potentially be transferred to pathogens under selective stress. In conclusion, presence of both resistance determinants could lead to co-selection during antimicrobial therapy or disinfection in hospitals or in food industries. PMID:11822776

  12. Comparison of Theoretical and Experimental Values for the Effective Heat of Ablation of Ammonium Chloride

    NASA Technical Reports Server (NTRS)

    Welker, Jean E.

    1960-01-01

    Thermodynamic properties of ammonium chloride have been obtained and applied to a theoretical analysis of the shielding mechanism which reduces the rate of heat transfer to a body when ablation takes place at the surface. The analysis has considered the mechanism as one in which the material sublimes directly from the solid to the vapor phase. The results of the computation are compared with the experimental results obtained from the Langley 700-kilowatt arc jet.

  13. Solubility of hydrogen sulfide in aqueous solutions of the single salts sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride at temperatures from 313 to 393 K and total pressures up to 10 MPa

    SciTech Connect

    Xia, J.; Kamps, A.P.S.; Rumpf, B.; Maurer, G.

    2000-04-01

    New experimental results for the solubility of hydrogen sulfide in aqueous solutions of the single salts sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride at temperatures from 313 to 393 K and total pressures up to 10 MPa are reported. As in the salt-free system, a second-hydrogen sulfide-rich--liquid phase is observed at high hydrogen sulfide concentrations. A model to describe the phase equilibrium is presented. Calculations are compared to the new experimental data.

  14. Radiation Stability of Benzyl Tributyl Ammonium Chloride towards Technetium-99 Extraction - 13016

    SciTech Connect

    Paviet-Hartmann, Patricia; Horkley, Jared; Campbell, Keri [Idaho National Laboratory, 2525 Fremont Street, Idaho Falls, ID 83402 (United States)] [Idaho National Laboratory, 2525 Fremont Street, Idaho Falls, ID 83402 (United States); Roman, Audrey [University of Nevada - Las Vegas, Harry Reid Center, 4505 S. Maryland Pkwy, Box 4009, Las Vegas, NV 89154-4009 (United States)] [University of Nevada - Las Vegas, Harry Reid Center, 4505 S. Maryland Pkwy, Box 4009, Las Vegas, NV 89154-4009 (United States); Nunez, Ana; Espartero, Amparo [CIEMAT, Avda Complutense, 40, 28040- Madrid (Spain)] [CIEMAT, Avda Complutense, 40, 28040- Madrid (Spain)

    2013-07-01

    A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning processes, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, the UREX process has been developed in the United States to co-extract hexavalent uranium (U) and hepta-valent technetium (Tc) by tri-n-butyl phosphate (TBP). Tc-99 is recognized to be one of the most abundant, long-lived radio-toxic isotopes in UNF (half-life, t{sub 1/2} = 2.13 x 10{sup 5} years), and as such, is targeted in UNF separation strategies for isolation and encapsulation in solid waste-forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste-form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flowsheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste-forms for ultimate disposal. In addition, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste-forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macro-compounds such as crown-ethers, aza-crown ethers, quaternary ammonium salts, and resorcin-arenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO{sub 4}{sup -} by benzyl tributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand's matrix conditions and concentration, as well as varying the organic phase composition (i.e. diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using an external Co-60 source. Post-irradiation solvent extraction measurements will be discussed. (authors)

  15. The Nature of Excess Intercalation of a Quaternary Ammonium Compound in Smectite Clay

    NASA Astrophysics Data System (ADS)

    Lafer, D. A.; Giese, R.

    2010-12-01

    Particular clay minerals, such as the French green clay used by Brunet de Courssou in the treatment of Mycobacterium ulcerans, have intrinsic antibacterial properties that surpass those of most conventional antibiotic treatments. The antimicrobial properties of the French green clay, comprised of 24% Fe-illite and 50% Fe-smectite, have been reproduced by a synthetically generated organically modified smectite (organoclay). The quaternary ammonium compound hexadecyl-trimethyl ammonium bromide (HDTMA) must undergo a cation exchange process in excess of the calculated cation exchange capacity (CEC) to render the clay antimicrobial. This work explores the position of the excess bonding within the clay lattice so as to challenge the hydrophobic bonding hypothesis proposed by Zhao et al (2003) concerning excess intercalation. After determining the CEC of BP smectite, organoclays were produced containing concentrations of one, two, and three times the CEC of HDTMA. Powder X-ray diffraction (PXRD) on a scale of 2 to 20 degrees 2theta was conducted on each of the three organoclays to infer the loading capacity of the smectite by means of the clay’s d-spacing as a proxy for expansion. Liquid Chromatography/Mass Spectrometry (LC-MS) quantitatively determined the surfactant retained on the clay by measuring the residual HDTMA in solution after extracting the organoclay. The d-spacing of the three organoclays implied that the first CEC of HDTMA entered the interlayer as an anion by means of a cation exchange process while the second and third CEC were incorporated into the clay lattice by means of a “hydrophobic bonding” mechanism in which the excess surfactants formed associations with the counterion Br+. Fourier transform infrared (FT-IR) spectra will be collected to determine the specific attachment of the excess bonding within the clay structure.

  16. Cyano-containing quaternary ammonium-based ionic liquid as a ‘co-solvent’ for lithium battery electrolyte

    Microsoft Academic Search

    Minato Egashira; Maika Nakagawa; Izumi Watanabe; Shigeto Okada; Jun-ichi Yamaki

    2005-01-01

    Imidazolium-based ionic liquid is one of attractive candidates for advanced lithium battery electrolyte. However, its cathodic stability is not sufficient for the reversible charge–discharge of negative electrodes. The authors previously proposed a quaternary ammonium-based ionic liquid containing a cyano group (cyano-QA) as a film-forming electrolyte on the negative electrode surface. In the present study, several cyano-QA ionic liquids have been

  17. Preparation, surface-active properties, and antimicrobial activities of bis-quaternary ammonium salts from amines and epichlorohydrin

    Microsoft Academic Search

    Jan Chlebicki; Joanna W?grzy?ska; Irena Maliszewska; Magorzata O?wi?cimska

    2005-01-01

    A series of new cationic surfactants, bis-quaternary ammonium salts, were prepared from tert-alkylamine and a product of the reaction of epichlorohydrin with decyl- and dodecylamine, and their surface-active properties\\u000a were measured. Specifically, the critical micelle concentration (CMC), effectiveness of surface tension reduction (?CMC), surface excess concentration (?), area per molecule at the interface (A), and standard free energies of adsorption

  18. Preparation of 1,3-diacylglycerols and 1-alkyl-3-acylglycerols in the presence of quaternary ammonium salt

    Microsoft Academic Search

    I. Ikeda; X. P. Gu; I. Miyamoto; M. Okahara

    1989-01-01

    A series of symmetrical and racemic 1,3-diacylglycerols and 1-alkyl-3-acylglycerols were prepared simply, and in high yields,\\u000a by the reaction of carboxylic acids with glycidyl esters or glycidyl ethers in the presence of quaternary ammonium salt. The\\u000a effect of reaction conditions on the yield, the ratio of 1,3- and 1,2-diacylglycerols, and the stability of 1,3-diglycerides\\u000a are also discussed.

  19. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride)...

  20. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC)...

  1. Pathways of reductive fragmentation of heterocyclic nitroarylmethyl quaternary ammonium prodrugs of mechlorethamine.

    PubMed

    Kriste, Angela G; Tercel, Moana; Anderson, Robert F; Ferry, Dianne M; Wilson, William R

    2002-12-01

    Nitroarylmethyl quaternary (NMQ) ammonium salts have potential as prodrugs for enzymatic or radiolytic reduction to release amine effectors under hypoxia. Earlier studies demonstrated one-electron release of the cytotoxic amine mechlorethamine (HN2) from 4-nitroimidazolyl and 2-nitropyrrolyl NMQ prodrugs (but not from nitrobenzyl analogs) through intramolecular electron transfer. In this study we determined whether this is a general feature of heterocyclic NMQ prodrugs of HN2 and examined the reductive pathways in detail using pulse and steady-state radiolysis. The kinetics of radical fragmentation varied by more than four orders of magnitude, independently of the one-electron reduction potential, within the series of eight nitroheterocycles examined. In addition to the compounds identified previously, new 2-nitropyrrole and 3-nitrothiophene NMQ prodrugs were found to provide efficient HN2 release (G > 0.5 micromol/J in anoxic formate buffer). However, the nitrothiophene was sensitive to nucleophilic displacement of HN2, making it less promising. Product analysis by HPLC/mass spectrometry identified symmetrical dimers arising from benzyl-type radical intermediates but also demonstrated that these dimers are not reliable markers for the intramolecular fragmentation of the initial nitro radical anion. This study elucidated multiple competing pathways for reductive fragmentation of NMQ prodrugs and identified the preferred electron acceptors for use in the development of analogs that release more potent cytotoxins. PMID:12452778

  2. Preparation and characterization of montmorillonite modified by phosphorus-nitrogen containing quaternary ammonium salts

    NASA Astrophysics Data System (ADS)

    Huang, Guobo; Gao, Jianrong; Wang, Xu

    2012-02-01

    A novel class of phosphorous-nitrogen containing quaternary ammonium salts (PNQAS) were synthesized and used as modifiers for sodium montmorillonite (Na-MMT). Montmorillonites modified by PNQAS (PNQAS-MMT) were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), dispersibility measurement and thermogravimetric analysis (TGA). The results show that the PNQAS have been intercalated into the montmorillonite layers successfully and the basal spacing of PNQAS-MMT is 1.70-2.65 nm. The XRD results show that the basal spacing of PNQAS-MMT reaches a maximum when PNQAS/CEC molar ratio is above 1.2. The increase of chain length of PNQAS is beneficial to expand the interlayer space of the MMT. The TEM and dispersibility measurement results show that PNQAS-MMT have stronger hydrophobicity and better dispersion than Na-MMT. The TGA results reveal that the thermal stability for PNQAS-MMT is affected by the structure and composition of intercalated PNQAS cations. The Tinital of PNQAS-MMT is between 286 °C and 385 °C, which can be applied to the modification of the polymer as a halogen-free flame retardant.

  3. Unique Inner Pore Properties of BK Channels Revealed by Quaternary Ammonium Block

    PubMed Central

    Li, Weiyan; Aldrich, Richard W.

    2004-01-01

    Potassium channels have a very wide distribution of single-channel conductance, with BK type Ca2+-activated K+ channels having by far the largest. Even though crystallographic views of K+ channel pores have become available, the structural basis underlying BK channels' large conductance has not been completely understood. In this study we use intracellularly applied quaternary ammonium compounds to probe the pore of BK channels. We show that molecules as large as decyltriethylammonium (C10) and tetrabutylammonium (TBA) have much faster block and unblock rates in BK channels when compared with any other tested K+ channel types. Additionally, our results suggest that at repolarization large QA molecules may be trapped inside blocked BK channels without slowing the overall process of deactivation. Based on these findings we propose that BK channels may differ from other K+ channels in its geometrical design at the inner mouth, with an enlarged cavity and inner pore providing less spatially restricted access to the cytoplasmic solution. These features could potentially contribute to the large conductance of BK channels. PMID:15197222

  4. Identification and composition of emerging quaternary ammonium compounds in municipal sewage sludge in China.

    PubMed

    Ruan, Ting; Song, Shanjun; Wang, Thanh; Liu, Runzeng; Lin, Yongfeng; Jiang, Guibin

    2014-04-15

    Quaternary ammonium compounds (QACs) have raised considerable attention due to their wide commercial applications and recent discovery of unknown persistent analogues in aqueous environment. In this work, the occurrence and distribution of alkyltrimethylammonium (ATMAC), benzylakyldimethylethylammonium (BAC) and dialkyldimethylammonium (DADMAC) homologues were investigated in fifty-two municipal sewage sludge samples. ATMAC C10-18, BAC C8-18 and paired DADMAC C8:8-C18:18 as well as emerging homologues such as ATMAC-20, 22 and mixed DADMAC-16:18 and 14:16 were present. Furthermore, paired DADMAC-20:20 and mixed DADMAC-14:18, 18:20 were identified for the first time by nontarget qualitative strategies. A triple quadruple mass spectrometer quantification method was also initially verified with the aid of laboratory synthesized standards for the analysis of the mixed DADMACs with no certificated commercial standards currently available. The total concentrations of ATMACs, BACs and DADMACs were in the range of 0.38-293, 0.09-191 and 0.64-344 ?g/g dry weight, respectively, and particularly, mixed DADMACs constituted 39 ± 7% of total DADMAC concentrations. The concentrations and profiles of individual homologues further suggested different QAC applications and fate in China. Significant correlations were also found among the concentrations of various QAC homologues as well as wastewater treatment plant (WWTP) characteristics (total organic carbon contents and daily treatment volumes). PMID:24654682

  5. Effect of polyelectrolytes and quaternary ammonium compounds on the anaerobic biological treatment of poultry processing wastewater.

    PubMed

    Tezel, Ulas; Pierson, John A; Pavlostathis, Spyros G

    2007-03-01

    Quaternary ammonium compounds (QACs) and polyelectrolytes are extensively used in poultry processing facilities as sanitizing agents and flocculants, respectively. These chemicals may affect the performance of biological treatment systems resulting in low effluent quality. The impact of these chemicals on the anaerobic treatment of poultry processing wastewater (PPWW) samples, collected before and after a solids separation process, was tested in batch assays using a mixed, mesophilic (35 degrees C) methanogenic culture. The results of this study showed that Vigilquat (VQ), a commercial mixture of four QACs, has a high affinity for the organic solids in the PPWW. Cationic and anionic polyelectrolytes, alone or in combination, did not have any adverse effect on the anaerobic biodegradation of PPWW at concentrations typically used in poultry processing facilities (20 and 5 mg/L, respectively). In spite of the high affinity of VQ for the PPWW solids, VQ at a concentration of 50mg/L and above adversely affected the anaerobic degradation of the PPWW, which resulted in a significantly reduced methane production and accumulation of volatile fatty acids. In the absence of any inhibition, the methane yield varied from 0.76 to 0.98 L methane at STP per g volatile solids added. VQ was not biodegraded under the batch, methanogenic conditions used in this study. PMID:17287000

  6. Mitochondrial Dysfunction Is the Focus of Quaternary Ammonium Surfactant Toxicity to Mammalian Epithelial Cells

    PubMed Central

    Inácio, Ângela S.; Costa, Gabriel N.; Domingues, Neuza S.; Santos, Maria S.; Moreno, António J. M.; Vaz, Winchil L. C.

    2013-01-01

    Surfactants have long been known to have microbicidal action and have been extensively used as antiseptics and disinfectants for a variety of general hygiene and clinical purposes. Among surfactants, quaternary ammonium compounds (QAC) are known to be the most useful antiseptics and disinfectants. However, our previous toxicological studies showed that QAC are also the most toxic surfactants for mammalian cells. An understanding of the mechanisms that underlie QAC toxicity is a crucial first step in their rational use and in the design and development of more effective and safer molecules. We show that QAC-induced toxicity is mediated primarily through mitochondrial dysfunction in mammalian columnar epithelial cell cultures in vitro. Toxic effects begin at sublethal concentrations and are characterized by mitochondrial fragmentation accompanied by decreased cellular energy charge. At very low concentrations, several QAC act on mitochondrial bioenergetics through a common mechanism of action, primarily by inhibiting mitochondrial respiration initiated at complex I and, to a lesser extent, by slowing down coupled ADP phosphorylation. The result is a reduction of cellular energy charge which, when reduced below 50% of its original value, induces apoptosis. The lethal effects are shown to be primarily a result of this process. At higher doses (closer to the critical micellar concentration), QAC induce the complete breakdown of cellular energy charge and necrotic cell death. PMID:23529737

  7. Determination of quaternary ammonium herbicides in soils. Comparison of digestion, shaking and microwave-assisted extractions.

    PubMed

    Pateiro-Moure, Miriam; Martínez-Carballo, Elena; Arias-Estévez, Manuel; Simal-Gándara, Jesús

    2008-07-01

    Very challenging analytical problems arise from the continuous introduction in agriculture of chemical pesticides. Particularly, diquat (DQ), paraquat (PQ) and difenzoquat (DF) are a difficult group of quaternary ammonium herbicides to analyze. This article reviews and addresses the most relevant analytical methods for determining the selected herbicides in soil. We discuss and critically evaluate procedures, such as digestion-based methods, shaking extraction and microwave-assisted extraction (MAE). Clean-up of extracts was performed by solid-phase extraction (SPE) using silica cartridges. Detection of these herbicides was carried out by liquid chromatography (LC) coupled to UV detection and mass spectrometry (MS) as confirmatory technique. Recoveries ranged from 98% to 100% by digestion, from no recovered to 61% by shaking, and from 102% to 109% by MAE with estimated quantification limits between 1.0 microg/kg and 2.0 microg/kg by digestion and 5.0 mug/kg and 7.5 microg/kg by MAE using LC/MS-MS as detection technique. The recoveries obtained under the optimum conditions are compared and discussed with those obtained from digestion extraction and MAE. PMID:18423476

  8. Enhanced oral absorption of hydrophobic and hydrophilic drugs using quaternary ammonium palmitoyl glycol chitosan nanoparticles.

    PubMed

    Siew, Adeline; Le, Hang; Thiovolet, Marion; Gellert, Paul; Schatzlein, Andreas; Uchegbu, Ijeoma

    2012-01-01

    As 95% of all prescriptions are for orally administered drugs, the issue of oral absorption is central to the development of pharmaceuticals. Oral absorption is limited by a high molecular weight (>500 Da), a high log P value (>2.0) and low gastrointestinal permeability. We have designed a triple action nanomedicine from a chitosan amphiphile: quaternary ammonium palmitoyl glycol chitosan (GCPQ), which significantly enhances the oral absorption of hydrophobic drugs (e.g., griseofulvin and cyclosporin A) and, to a lesser extent, the absorption of hydrophilic drugs (e.g., ranitidine). The griseofulvin and cyclosporin A C(max) was increased 6- and 5-fold respectively with this new nanomedicine. Hydrophobic drug absorption is facilitated by the nanomedicine: (a) increasing the dissolution rate of hydrophobic molecules, (b) adhering to and penetrating the mucus layer and thus enabling intimate contact between the drug and the gastrointestinal epithelium absorptive cells, and (c) enhancing the transcellular transport of hydrophobic compounds. Although the C(max) of ranitidine was enhanced by 80% with the nanomedicine, there was no appreciable opening of tight junctions by the polymer particles. PMID:22047066

  9. The Inhibitory Effects of Quaternary Ammonium Methacrylates on Soluble and Matrix-bound MMPs

    PubMed Central

    Tezvergil-Mutluay, A.; Agee, K.A.; Uchiyama, T.; Imazato, S.; Mutluay, M.M.; Cadenaro, M.; Breschi, L.; Nishitani, Y.; Tay, F.R.; Pashley, D.H.

    2011-01-01

    Matrix metalloproteinases (MMPs) bound to dentin contribute to the progressive degradation of collagen fibrils in hybrid layers created by dentin adhesives. This study evaluated the MMP-inhibiting potential of quaternary ammonium methacrylates (QAMs), with soluble rhMMP-9 and a matrix-bound endogenous MMP model. Six different QAMs were initially screened by a rhMMP-9 colorimetric assay. For the matrix-bound endogenous MMPs, we aged demineralized dentin beams for 30 days in calcium- and zinc-containing media (CM; control), chlorhexidine, or QAMs in CM to determine the changes in dry mass loss and solubilization of collagen peptides against baseline levels. The inhibitory effects of QAMs on soluble rhMMP-9 varied between 34 and 100%. Beams incubated in CM showed a 29% decrease in dry mass (p < 0.05), whereas beams incubated with QAMs showed only 0.2%-6% loss of dry mass. Significantly more solubilized collagen was detected from beams incubated in CM (p < 0.05). It is concluded that QAMs exhibited dentin MMP inhibition comparable with that of chlorhexidine, but required higher concentrations. PMID:21212315

  10. A DFT-based QSAR study of the toxicity of quaternary ammonium compounds on Chlorella vulgaris.

    PubMed

    Zhu, Menjun; Ge, Fei; Zhu, Runliang; Wang, Xueye; Zheng, Xiaoyan

    2010-06-01

    The DFT-based descriptors were used to derive the quantitative structure-activity relationship (QSAR) models enabling the calculated quantum chemistry parameters to be correlated to the toxicity of quaternary ammonium compounds (QACs) on green alga Chlorella vulgaris. DFT/B3LYP level of theory with the 6-31G(d) basis set was applied to calculate a set of quantum chemistry descriptors for 11 QACs. The partial least squares (PLS) analysis implemented in Simca-P was employed to obtain the QSAR models. The optimal PLS model with the cumulative cross-validated regression coefficient (Q(cum)(2)=0.893) and the correlation coefficient between observed values and fitted values (R=0.975) explained 95.3% of the variance of the independent variables and 92.8% of the variance of the dependent variable. The results of this investigation show that alkyl chain lengths (CL), polarizability tense (alpha(zz)), the most positive net atomic charges on a hydrogen atom (q(H)(+)) and entropy (S(o)) are the major descriptors in governing the log(1/EC(50)) values of the QACs. PMID:20417544

  11. Dental plaque microcosm biofilm behavior on calcium phosphate nanocomposite with quaternary ammonium

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Zhang, Ke; Wu, Eric; Xu, Sarah M.; Zhou, Xuedong; Xu, Hockin H. K.

    2012-01-01

    Objectives Half of dental restorations fail in 10 years, with secondary caries as the main reason. Calcium phosphate composites could remineralize tooth lesions. The objectives of this study were to: (1) Impart antibacterial activity to a composite with nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate the effect of quaternary ammonium dimethacrylate (QADM) on mechanical and dental plaque microcosm biofilm properties for the first time. Methods The NACP and glass particles were filled into a dental resin that contained bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM. NACP nanocomposites containing 0%, 7%, 14%, and 17.5% of QADM by mass, respectively, were photo-cured. A commercial composite with no antibacterial activity was used as control. Mechanical properties were measured in three-point flexure. A human saliva microcosm model was used to grow biofilms on composites. Live/dead assay, metabolic activity, colony-forming unit (CFU) counts, and lactic acid production of biofilms on the composites were measured. Results Increasing QADM mass fraction monotonically reduced the biofilm viability, CFU and lactic acid. Biofilms on NACP nanocomposite with 17.5% QADM had metabolic activity that was 30% that on a commercial composite control (p<0.05). Total microorganisms, total streptococci, and mutans streptococci CFU counts (mean±sd; n=6) on composite control was 6-fold those on NACP+17.5% QADM nanocomposite. Composite control had long strings of cells with normal short-rod shapes, while some cells on NACP-QADM nanocomposites disintegrated into pieces. Adding QADM to NACP did not decrease the strength and elastic modulus, which matched (p>0.1) those of a commercial composite without Ca-PO4 or antibacterial activity. Significance A dental plaque microcosm model was used to evaluate the novel NACP-QADM nanocomposite. The nanocomposite greatly reduced the biofilm viability, metabolic activity and lactic acid, while its mechanical properties matched those of a commercial composite. NACP-QADM nanocomposite with calcium phosphate fillers, good mechanical properties and a strong antibacterial activity may have potential for anti-biofilm and anti-caries restorations. PMID:22578992

  12. Identification of quaternary ammonium compounds as potent inhibitors of hERG potassium channels

    PubMed Central

    Xia, Menghang; Shahane, Sampada; Huang, Ruili; Titus, Steven A.; Shum, Enoch; Zhao, Yong; Southall, Noel; Zheng, Wei; Witt, Kristine L.; Tice, Raymond R.; Austin, Christopher P.

    2011-01-01

    The human ether-a-go-go-related gene (hERG) channel, a member of a family of voltage-gated potassium (K+) channels, plays a critical role in the repolarization of the cardiac action potential. The reduction of hERG channel activity as a result of adverse drug effects or genetic mutations may cause QT interval prolongation and potentially lead to acquired long QT syndrome. Thus, screening for hERG channel activity is important in drug development. Cardiotoxicity associated with the inhibition of hERG channels by environmental chemicals is also a public health concern. To assess the inhibitory effects of environmental chemicals on hERG channel function, we screened the National Toxicology Program (NTP) collection of 1408 compounds by measuring thallium influx into cells through hERG channels. Seventeen compounds with hERG channel inhibition were identified with IC50 potencies ranging from 0.26 to 22 ?M. Twelve of these compounds were confirmed as hERG channel blockers in an automated whole cell patch clamp experiment. In addition, we investigated the structure-activity relationship of seven compounds belonging to the quaternary ammonium compound (QAC) series on hERG channel inhibition. Among four active QAC compounds, tetra-n-octylammonium bromide was the most potent with an IC50 value of 260 nM in the thallium influx assay and 80 nM in the patch clamp assay. The potency of this class of hERG channel inhibitors appears to depend on the number and length of their aliphatic side-chains surrounding the charged nitrogen. Profiling environmental compound libraries for hERG channel inhibition provides information useful in prioritizing these compounds for cardiotoxicity assessment in vivo. PMID:21362439

  13. Antibacterial amorphous calcium phosphate nanocomposites with a quaternary ammonium dimethacrylate and silver nanoparticles

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Xu, Hockin H. K.; Antonucci, Joseph M.; Kraigsley, Alison M.; Lin, Nancy J.; Lin-Gibson, Sheng; Zhou, Xuedong

    2012-01-01

    Objectives Calcium and phosphate ion-releasing resin composites are promising for remineralization. However, there has been no report on incorporating antibacterial agents to these composites. The objective of this study was to develop antibacterial and mechanically-strong nanocomposites incorporating a quaternary ammonium dimethacrylate (QADM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP). Methods The QADM, bis(2-methacryloyloxyethyl) dimethylammonium bromide (ionic dimethacrylate-1), was synthesized from 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate. Ng was synthesized by dissolving Ag 2-ethylhexanoate salt in 2-(tertbutylamino)ethyl methacrylate. Mechanical properties were measured in three-point flexure with bars of 2×2×25 mm (n = 6). Composite disks (diameter = 9 mm, thickness = 2 mm) were inoculated with Streptococcus mutans. The metabolic activity and lactic acid production of biofilms were measured (n = 6). Two commercial composites were used as controls. Results Flexural strength and elastic modulus of NACP+QADM, NACP+NAg, and NACP+QADM+NAg matched those of commercial composites with no antibacterial property (p > 0.1). The NACP+QADM+NAg composite decreased the titer counts of adherent S. mutans biofilms by an order of magnitude, compared to the commercial composites (p < 0.05). The metabolic activity and lactic acid production of biofilms on NACP+QADM+NAg composite were much less than those on commercial composites (p < 0.05). Combining QADM and NAg rendered the nanocomposite more strongly antibacterial than either agent alone (p < 0.05). Significance QADM and NAg were incorporated into calcium phosphate composite for the first time. NACP+QADM+NAg was strongly-antibacterial and greatly reduced the titer counts, metabolic activity, and acid production of S. mutans biofilms, while possessing mechanical properties similar to commercial composites. These nanocomposites are promising to have the double benefits of remineralization and antibacterial capabilities to inhibit dental caries. PMID:22305716

  14. Synthesis of new antibacterial quaternary ammonium monomer for incorporation into CaP nanocomposite

    PubMed Central

    Zhou, Chenchen; Weir, Michael D.; Zhang, Ke; Deng, Dongmei; Cheng, Lei; Xu, Hockin H. K.

    2013-01-01

    Objectives Composites are the principal material for tooth cavity restorations due to their esthetics and direct-filling capabilities. However, composites accumulate biofilms in vivo, and secondary caries due to biofilm acids is the main cause of restoration failure. The objectives of this study were to: (1) synthesize new antibacterial monomers; and (2) develop nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and antibacterial monomer. Methods Two new antibacterial monomers were synthesized: dimethylaminohexane methacrylate (DMAHM) with a carbon chain length of 6, and dimethylaminododecyl methacrylate (DMADDM) with a chain length of 12. A spray-drying technique was used to make NACP. DMADDM was incorporated into NACP nanocomposite at mass fractions of 0%, 0.75%, 1.5%, 2.25% and 3%. A flexural test was used to measure composite strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was used to measure viability, metabolic activity, and lactic acid production of biofilms on composites. Results The new DMAHM was more potent than a previous quaternary ammonium dimethacrylate (QADM). DMADDM was much more strongly antibacterial than DMAHM. The new DMADDM-NACP nanocomposite had strength similar to that of composite control (p > 0.1). At 3% DMADDM in the composite, the metabolic activity of adherent biofilms was reduced to 5% of that on composite control. Lactic acid production by biofilms on composite containing 3% DMADDM was reduced to only 1% of that on composite control. Biofilm colony-forming unit (CFU) counts on composite with 3% DMADDM were reduced by 2-3 orders of magnitude. Significance New antibacterial monomers were synthesized, and the carbon chain length had a strong effect on antibacterial efficacy. The new DMADDM-NACP nanocomposite possessed potent anti-biofilm activity without compromising load-bearing properties, and is promising for antibacterial and remineralizing dental restorations to inhibit secondary caries. PMID:23768794

  15. Molecular dynamics simulation of secondary sorption behavior of montmorillonite modified by single chain quaternary ammonium cations.

    PubMed

    Zhao, Qian; Burns, Susan E

    2012-04-01

    Organoclays synthesized from single chain quaternary ammonium cations (QAC) ((CH(3))(3)NR(+)) exhibit different mechanisms for the sorption of nonpolar organic compounds as the length of the carbon chain is increased. The interaction between a nonpolar sorbate and an organoclay intercalated with small QACs has been demonstrated to be surface adsorption, while partitioning is the dominant mechanism in clays intercalated with long chain surfactants. This study presents the results of a molecular dynamics (MD) simulation performed to examine the sorption mechanisms of benzene in the interlayer of three organoclays with chain lengths ranging from 1 to 16 carbons: tetramethylammonium (TMA) clay; decyltrimethylammonium (DTMA) clay; and hexadecyltrimethylammonium (HDTMA) clay. The basis of the overall simulation was a combined force field of ClayFF and CVFF. In the simulations, organic cations were intercalated and benzene molecules were introduced to the interlayer, followed by whole system NPT and NVT time integration. Trajectories of all the species were recorded after the system reached equilibrium and subsequently analyzed. Simulation results confirmed that the arrangement of the surfactants controlled the sorption mechanism of organoclays. Benzene molecules were observed to interact directly with the clay surface in the presence of TMA cations, but tended to interact with the aliphatic chain of the HDTMA cation in the interlayer. The simulation provided insight into the nature of the adsorption/partitioning mechanisms in organoclays, and explained experimental observations of decreased versus increased uptake capacities as a function of increasing total organic carbon (TOC) for TMA clay and HDTMA clay, respectively. The transition of sorption mechanisms was also quantified with simulation of DTMA clay, with a chain length between that of TMA and HDTMA. Furthermore, this study suggested that at the molecular level, the controlling factor for the ultimate sorption capacity is available surface sites in the case of TMA clay, and density of aliphatic chains within the interlayer space for HDTMA clay. PMID:22364194

  16. Effects of Quaternary-Ammonium-Based Formulations on Bacterial Community Dynamics and Antimicrobial Susceptibility

    PubMed Central

    McBain, Andrew J.; Ledder, Ruth G.; Moore, Louise E.; Catrenich, Carl E.; Gilbert, Peter

    2004-01-01

    Quaternary ammonium compounds (QACs) are widely used as adjuncts to hygiene in domestic cleaning products. Current concern that the increased use of such biocides in consumer products might contribute to the emergence of antibiotic resistance has led us to examine the effects of a QAC-containing domestic cleaning fluid on the population dynamics and antimicrobial susceptibility of domestic sink drain biofilm communities. QAC susceptibilities of numerically dominant, culturable drain bacteria (15 genera, 17 species) were determined in vitro before and after repeated QAC exposure (14 passages). A fully characterized drain microcosm was then exposed to short-term (12 days) and long-term (3 months) dosing with a QAC-containing domestic detergent (QD). QAC exposure of isolated cultures caused both increases (three species) and circa twofold decreases (six species) in QAC susceptibility. The susceptibility of Ralstonia sp. was considerably decreased following 14 consecutive QAC passages. Control drain microcosm biofilms maintained dynamic stability, as evidenced by culture and denaturing gradient gel electrophoresis (DGGE) analysis. Bacterial population densities were largely unaffected during short-term exposure to use levels of QD, although 50% QD caused circa 10-fold viability reductions. DGGE analysis supported these observations; identified the major microcosm genera as Pseudomonas, Pseudoalteromonas, Erwinia, and Enterobacter, and showed that aeromonads increased in abundance under 10 to 50% QD. Long-term exposure of the microcosms to QD did not significantly alter the pattern of antimicrobial susceptibility. These data demonstrate the recalcitrance of domestic drain biofilms toward QAC and that although repeated QAC exposure of drain isolates in pure culture results in susceptibility change in some test bacteria, such changes do not necessarily occur within complex communities. PMID:15184143

  17. Mapping peptide thiol accessibility in membranes using a quaternary ammonium isotope-coded mass tag (ICMT)

    PubMed Central

    Su, Chiao-Yung; London, Erwin; Sampson, Nicole S.

    2013-01-01

    The plasma membrane contains a diverse array of proteins, including receptors, channels, and signaling complexes, that serve as decision-making centers. Investigation of membrane protein topology is important for understanding the function of these types of protein. Here, we report a method to determine protein topology in the membrane that utilizes labeling of cysteine with isotope-coded mass tags. The mass tags contain a thiol reactive moiety, linker, and a quaternary ammonium group to aid ionization in the mass spectrometer and were synthesizes as both light and heavy (deuterated) forms. The probes were found to be membrane impermeable when applied to lipid vesicles. To assess the utility of the probes for mapping peptide thiol topology, we employed a two-step labeling procedure. Vesicles containing ?-helical transmembrane peptides were labeled with heavy (or light) probe, solubilized by detergent, and then labeled by an excess of the complementary probe. Peptide for which the cysteine was oriented in the center of the lipid bilayer was not labeled until the lipid vesicles were lysed with detergent, consistent with the membrane impermeability of the probes and reduced ionization of the thiol in the hydrophobic membrane. Peptide for which the cysteine was positioned in the head group zone of the lipid bilayer was labeled rapidly. Peptide for which the cysteine was positioned below the head group abutting the hydrocarbon region was labeled at a reduced rate compared to the fully accessible cysteine. Moreover, the effect of lipid bilayer structure on the kinetics of peptide and lipid flipping in the bilayer was readily measured with our two-step labeling method. The small sample size required, the ease and rapidity of sample preparation, and the amenability of MALDI-TOF mass spectral to analysis in the presence of lipids will enable future facile investigation of membrane proteins in a cellular context. PMID:23725486

  18. Synthesis, characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides.

    PubMed

    Liu, Wen-Shuai; Wang, Chun-Hua; Sun, Ju-Feng; Hou, Gui-Ge; Wang, Yu-Peng; Qu, Rong-Jun

    2015-01-01

    Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple. PMID:25215430

  19. Synthesis, characterization, and antibacterial activity of N,O-quaternary ammonium chitosan.

    PubMed

    Xu, Tao; Xin, Meihua; Li, Mingchun; Huang, Huili; Zhou, Shengquan; Liu, Juezhao

    2011-11-01

    N,N,N-Trimethyl O-(2-hydroxy-3-trimethylammonium propyl) chitosans (TMHTMAPC) with different degrees of O-substitution were synthesized by reacting O-methyl-free N,N,N-trimethyl chitosan (TMC) with 3-chloro-2-hydroxy-propyl trimethyl ammonium chloride (CHPTMAC). The products were characterized by (1)H NMR, FTIR and TGA, and investigated for antibacterial activity against Staphylococcus aureus and Escherichia coli under weakly acidic (pH 5.5) and weakly basic (pH 7.2) conditions. TMHTMAPC exhibited enhanced antibacterial activity compared with TMC, and the activity of TMHTMAPC increased with an increase in the degree of substitution. Divalent cations (Ba(2+) and Ca(2+)) strongly reduced the antibacterial activity of chitosan, O-carboxymethyl chitosan and N,N,N-trimethyl-O-carboxymethyl chitosan, but the repression on the antibacterial activity of TMC and TMHTMAPC was weaker. This indicates that the free amino group on chitosan backbone is the main functional group interacting with divalent cations. The existence of 100 mM Na(+) slightly reduced the antibacterial activity of both chitosan and its derivatives. PMID:21920510

  20. Superposition model study of Cr3+ doped tetra methyl ammonium cadmium chloride

    NASA Astrophysics Data System (ADS)

    Kripal, Ram; Yadav, Awadhesh Kumar

    2015-02-01

    The zero field splitting parameter D of Cr3+ doped in tetra methyl ammonium cadmium chloride (TMCC) is calculated with perturbation formula using microscopic spin Hamiltonian theory and crystal field parameters from superposition model. The theoretically calculated ZFS parameter for Cr3+ in TMCC single crystal is compared with the experimental value obtained by electron paramagnetic resonance (EPR). The local structure distortion is considered to obtain the crystal field parameters. The theoretical study gives the ZFS parameter D similar to that from experiment. However, calculation considering small distortion in local structure around Cr3+ gives better agreement with the experimental value of ZFS parameter.

  1. Superposition model study of Cr3+ doped tetra methyl ammonium cadmium chloride.

    PubMed

    Kripal, Ram; Yadav, Awadhesh Kumar

    2015-02-25

    The zero field splitting parameter D of Cr(3+) doped in tetra methyl ammonium cadmium chloride (TMCC) is calculated with perturbation formula using microscopic spin Hamiltonian theory and crystal field parameters from superposition model. The theoretically calculated ZFS parameter for Cr(3+) in TMCC single crystal is compared with the experimental value obtained by electron paramagnetic resonance (EPR). The local structure distortion is considered to obtain the crystal field parameters. The theoretical study gives the ZFS parameter D similar to that from experiment. However, calculation considering small distortion in local structure around Cr(3+) gives better agreement with the experimental value of ZFS parameter. PMID:25233033

  2. Hydrogen bonding Part 39. Hydrogen bonding by ?-CH in quaternary ammonium salts and the possible role of C?H⋯B hydrogen bonds in acetylcholine—receptor interactions

    NASA Astrophysics Data System (ADS)

    Harmon, Kenneth M.; De Santis, Nancy J.; Brandt, Dale O.

    1992-01-01

    Correlation of IR spectral properties with crystallographic data for tetramethylammonium ion salts shows that C?H⋯B hydrogen bonding in quaternary ammonium ions salts can be assumed to be present when ( rC⋯B)?( rvdwB+0.95Å)<1.00 Å. The value 0.95 Å is the average C?H bond length shown by ?-C?H (H?C?N + for a variety of quaternary ammonium ions. This approach allows estimation of the presence or absence of C?H⋯B hydrogen bonding is salts where hydrogens have not been located in diffraction studies. Application to choline chloride and acetylcholine chloride, bromide and iodide demostrates that C?H-to-anion hydrogen bonding is present is these salts. Since tetramethylammonium ion shows C?H⋯O hydrogen bonding with even the very weak acceptor ClO -4, it is likely that hydrogen bonding from the (CH 3) 3N +CH 2- group of acetylcholine to groups such as phosphate of carboxylate will play a role in the binding of acetylcholine to the anionic site of the receptor.

  3. Mobility and ionic association of lithium and quaternary ammonium salts in propylene carbonate and [gamma]-butyrolactone

    SciTech Connect

    Ue, Makoto (Mitsubishi Petrochemical Co., Ltd., Ibaraki (Japan). Tsukuba Research Center)

    1994-12-01

    Propylene carbonate (PC) and [gamma]-butyrolactone (GBL) are important dipolar aprotic solvents used for nonaqueous electrolytes in high energy lithium batteries, aluminum electrolytic capacitors, and electrical double-layer capacitors. The conductivities of lithium and quaternary ammonium salts have been measured in propylene carbonate and [gamma]-butyrolactone at 25 C over the concentration range of 10[sup [minus]2] to 10[sup [minus]3] mol dm[sup [minus]3]. The limiting molar conductivities and the ionic association constants were calculated by the expanded Fuoss-Hsia equation. The mobility of anions in both solvents decreased in the following order: BF[sub 4][sup [minus

  4. Aerogels from quaternary ammonium-functionalized cellulose nanofibers for rapid removal of Cr(VI) from water.

    PubMed

    He, Xu; Cheng, Long; Wang, Yaru; Zhao, Jiangqi; Zhang, Wei; Lu, Canhui

    2014-10-13

    An efficient heavy metal adsorbent from quaternary ammonium-functionalized cellulose nanofiber aerogels was successfully developed. The highly porous aerogel could well retain its large specific surface area, which allowed rapid and effective removal of Cr(VI) from contaminated water. The aerogel adsorbent became mechanically robust after chemical crosslinking. It could be easily separated from water after adsorption without complicated centrifugation or filtration process. With only 1g of aerogel, more than 99% of Cr(VI) in 1L of 1mg/L solution could be removed in 50 min. Besides, the aerogel also exhibited excellent reusability. PMID:25037403

  5. Reversible Swelling of Chitosan and Quaternary Ammonium Modified Chitosan Brush Layers: Effect of pH and Counter Anion Size and Functionality

    PubMed Central

    Lee, Hyun-Su; Yee, Michael Q.; Eckmann, Yonaton Y.; Hickok, Noreen J.; Eckmann, David M.; Composto, Russell J.

    2012-01-01

    This study investigates the swelling of grafted polycationic brushes as a function of pH and anion type. The brushes are chitosan (CH) and chitosans with 27% and 51% degree of substitution (DS) of quaternary ammonium salt, denoted as CH-Q25 and CH-Q50, respectively. The water content and swelling behaviors are monitored using in situ quartz-crystal microbalance with dissipation (QCM-D). The pH varies from ~3.5 to 8.5, and the counter anion types include chloride, acetate, and citrate. At fixed pH, the water content and brush swelling increase as the DS increases. Whereas the CH-Q50 brush layer shows symmetric swelling with a minimum near pH = 4.5, the swelling of CH and CH-Q25 is relatively constant as pH decreases from 8.2 to 5.5, and then begins to increase near pH 4. These studies indicate that the symmetric swelling of CH-Q50 is likely attributed to increasing protonation of primary amines for pH values below pH 6.5 and the quaternary ammonium salts above pH 6.5. At pH 4, the swelling of the CH brush increases upon exchanging the smaller chloridewith a bulkier acetate anion, which is less effective at screening intra/inter molecular repulsion. In contrast, upon exchanging the acetate with trifunctional citrate, CH and CH-Q25 brushes collapse by 53 and 42%, respectively, because the citrate forms ionic cross-links. To test antibacterial properties, silicon oxide, CH and CH-Q50 brush layers are exposed to 107–108 cfu/ml of S. aureus for two days at 37 °C and exposed to stepped shear stresses in 2 min intervals. Whereas an S. aureus biofilm adheres strongly to silicon oxide and CH for stresses up to 12 dyne/cm2, biofilms on CH-Q50 detach at a relatively low shear stress, 1.5 dyne/cm2. Due to their high degree of swelling that can be tuned via pH, counterion size and type, chitosan and quaternary modified chitosans have potential as responsive coatings for applications including MEMS/NEMS devices and drug eluting implants. PMID:23209343

  6. Determination of quaternary ammonium compounds in oranges and cucumbers using QuEChERS extraction and ultra-performance liquid chromatography/tandem mass spectrometry.

    PubMed

    Arrebola-Liébanas, Francisco Javier; Abdo, María Angeles Herrera; Moreno, José Luis Fernandez; Martínez-Vidal, José L; Frenich, Antonia Garrido

    2014-01-01

    A simple and fast method has been developed for determining relevant quaternary ammonium compounds in cucumber and orange samples. The target compounds were benzoalkonium chloride (BAC-10, BAC-12, BAC-14, and BAC-16), didecyldimethylammonium chloride, and benzethonium chloride, all frequently used biocides in the agrifood industry. An extraction based on the buffered Quick, Easy, Cheap, Effective, Rugged, and Safe method and determination by ultra-performance LC/MS/MS that eluted the biocides in less than 5 min were used. The method was fully validated and implemented in a UNE-EN-ISO/IEC 17025 accredited laboratory for its application to the analysis of real samples. Performance characteristics of the method are reported, including an estimation of measurement uncertainty. Calibration curves were set between 0.01 and 0.150 mg/kg, LOD values were always between 0.4 and 1.0 microg/kg, LOQ values were in the range 1-4 microg/kg, recovery was between 81 and 115%, intraday and interday precision were always lower than 17% (expressed as RSD), and expanded uncertainty was always lower than 40%. The validation was accomplished for the two studied matrixes at spiking concentrations of 0.011 and 0.050 mg/kg. The method has been applied to the analysis of 30 cucumber and orange samples that were found to contain concentrations of BAC-12 that ranged between 0.015 and 0.210 mg/kg and of BAC-14 between 0.018 and 0.081 mg/kg. PMID:25145132

  7. Substituted Quaternary Ammonium Salts Improve Low-Temperature Performance of Double-Layer Capacitors

    NASA Technical Reports Server (NTRS)

    Brandon, Erik J.; Smart, Marshall C.; West, William C.

    2011-01-01

    Double-layer capacitors are unique energy storage devices, capable of supporting large current pulses as well as a very high number of charging and discharging cycles. The performance of doublelayer capacitors is highly dependent on the nature of the electrolyte system used. Many applications, including for electric and fuel cell vehicles, back-up diesel generators, wind generator pitch control back-up power systems, environmental and structural distributed sensors, and spacecraft avionics, can potentially benefit from the use of double-layer capacitors with lower equivalent series resistances (ESRs) over wider temperature limits. Higher ESRs result in decreased power output, which is a particular problem at lower temperatures. Commercially available cells are typically rated for operation down to only 40 C. Previous briefs [for example, Low Temperature Supercapacitors (NPO-44386), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), p. 32, and Supercapacitor Electrolyte Solvents With Liquid Range Below 80 C (NPO-44855), NASA Tech Briefs, Vol. 34, No. 1 (January 2010), p. 44] discussed the use of electrolytes that employed low-melting-point co-solvents to depress the freezing point of traditional acetonitrile-based electrolytes. Using these modified electrolyte formulations can extend the low-temperature operational limit of double-layer capacitors beyond that of commercially available cells. This previous work has shown that although the measured capacitance is relatively insensitive to temperature, the ESR can rise rapidly at low temperatures, due to decreased electrolyte conductance within the pores of the high surface- area carbon electrodes. Most of these advanced electrolyte systems featured tetraethylammonium tetrafluoroborate (TEATFB) as the salt. More recent work at JPL indicates the use of the asymmetric quaternary ammonium salt triethylmethylammonium tetrafluoroborate (TEMATFB) or spiro-(l,l')-bipyrrolidium tetrafluoroborate (SBPBF4) in a 1:1 by volume solvent mixture of acetonitrile (AN) and methyl formate (MF) enables double-layer capacitor cells to operate well below -40 C with a relatively low ESR. Typically, a less than twofold increase in ESR is observed at -65 C relative to room-temperature values, when these modified electrolyte blends are used in prototype cells. Double-layer capacitor coin cells filled with these electrolytes have displayed the lowest measured ESR for an organic electrolyte to date at low temperature (based on a wide range of electrolyte screening studies at JPL). The cells featured high-surface-area (approximately equal to 2,500 m/g) carbon electrodes that were 0.50 mm thick and 1.6 cm in diameter, and coated with a thin layer of platinum to reduce cell resistance. A polyethylene separator was used to electrically isolate the electrodes.

  8. Accelerated OH(-) transport in activated carbon air cathode by modification of quaternary ammonium for microbial fuel cells.

    PubMed

    Wang, Xin; Feng, Cuijuan; Ding, Ning; Zhang, Qingrui; Li, Nan; Li, Xiaojing; Zhang, Yueyong; Zhou, Qixing

    2014-04-01

    Activated carbon (AC) is a promising catalyst for the air cathode of microbial fuel cells (MFCs) because of its high performance and low cost. To increase the performance of AC air cathodes, the acceleration of OH(-) transport is one of the most important methods, but it has not been widely investigated. Here we added quaternary ammonium to ACs by in situ anchoring of a quaternary ammonium/epoxide-reacting compound (QAE) or ex situ mixing with anion exchange resins in order to modify ACs from not only the external surface but also inside the pores. In 50 mM phosphate buffer solution (PBS), the in situ anchoring of QAE was a more effective way to increase the power. The highest power density of 2781 ± 36 mW/m(2), which is 10% higher than that of the control, was obtained using QAE-anchored AC cathodes. When the medium was switched to an unbuffered NaCl solution, the increase in maximum power density (885 ± 25 mW/m(2)) was in accordance with the anion exchange capacity (0.219 mmol/g). The highest power density of the anion exchange resin-mixed air cathode was 51% higher than that of the control, indicating that anion exchange is urgently needed in real wastewaters. Excess anchoring of QAE blocked both the mesopores and micropores, causing the power output to be inhibited. PMID:24597673

  9. A Systematic Investigation of Quaternary Ammonium Ions as Asymmetric Phase Transfer Catalysts. Synthesis of Catalyst Libraries and Evaluation of Catalyst Activity

    PubMed Central

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

    2011-01-01

    Despite over three decades of research into asymmetric phase transfer catalysis (APTC), a fundamental understanding of the factors that affect the rate and stereoselectivity of this important process are still obscure. This paper describes the initial stages of a long-term program aimed at elucidating the physical organic foundations of APTC employing a chemoinformatic analysis of the alkylation of a protected glycine imine with a libraries of enantiomerically enriched quaternary ammonium ions. The synthesis of the quaternary ammonium ions follows a diversity oriented approach wherein the tandem inter[4+2]/intra[3+2] cycloaddition of nitroalkenes serves as the key transformation. A two part synthetic strategy comprised of: (1) preparation of enantioenriched scaffolds and (2) development of parallel synthesis procedures is described. The strategy allows for the facile introduction of four variable groups in the vicinity of a stereogenic quaternary ammonium ion. The quaternary ammonium ions exhibited a wide range of activity and to a lesser degree enantioselectivity. Catalyst activity and selectivity are rationalized in a qualitative way based on the effective positive potential of the ammonium ion. PMID:21446721

  10. Specific variations of fatty acid composition of Pseudomonas aeruginosa ATCC 15442 induced by quaternary ammonium compounds and relation with resistance to bactericidal activity.

    PubMed

    Guérin-Méchin, L; Dubois-Brissonnet, F; Heyd, B; Leveau, J Y

    1999-11-01

    The role of membrane fatty acid composition in the resistance of Pseudomonas aeruginosa ATCC 15442 to the bactericidal activity of Quaternary Ammonium Compounds (QACs) was investigated. The strain was grown in a medium with increasing concentrations of a QAC, benzyldimethyltetradecylammonium chloride (C14) and two non-QACs, sodium dichloroisocyanurate and tri-sodium phosphate. In the presence of C14 only, the strain was able to grow in concentrations higher than the minimal inhibitory concentration. As the strain adapted to C14, resistance to bactericidal activity of the same biocide increased. For the non-QACs, no change was noted when cells were grown in the presence of biocides. The C14-adapted cells showed variations in membrane fatty acid composition. A hierarchical clustering analysis was used to compare all fatty acid compositions of cultures in the presence, or not, of the three biocides used here and another QAC studied previously. The clusters obtained underlined specific variations of membrane fatty acids in response to the presence of QACs. Furthermore, with a simple linear regression analysis, a relationship was shown between the membrane fatty acids and the resistance developed by the strain against the bactericidal activity of C14. PMID:10594715

  11. Trace analysis in highly concentrated salt solutions of sodium chloride and ammonium fluoride using flame atomic absorption spectrometry

    Microsoft Academic Search

    Georgi Bekjarov; Veselin Kmetov; Lubomir Futekov

    1989-01-01

    Aqueous solutions of high salt concentration are subjected to direct flame atomic absorption analysis. Blockage of nebulizer and burner is eliminated by employing the dosage scheme “washing solution — sample — washing solution” effected by means of a specially designed device. The microtrace content of bismuth, zinc and copper in sodium chloride and of copper, lead and iron in ammonium

  12. Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

    NASA Astrophysics Data System (ADS)

    Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

    2014-04-01

    This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

  13. Cotton gauze bearing non-diffusible quaternary ammonium salts and featuring anti-microbial activity: An example of single-use articles tailored to self-sterilize

    E-print Network

    Taralp, Alpay

    Cotton gauze bearing non-diffusible quaternary ammonium salts and featuring anti-microbial activity envisaged in which single-use cotton gauze could be chemically tailored to display anti-microbial activity as AEM 5700, into the cotton matrix and polymerizing the monomers about the fibers. In a second approach

  14. Inverse-emulsion copolymerization of acrylamide and quaternary ammonium cationic monomers with block copolymeric surfactants: copolymer composition control using batch and semi-batch techniques

    Microsoft Academic Search

    José Hernández-Barajas; David J. Hunkeler

    1997-01-01

    An experimental investigation of the inverse-emulsion copolymerization of acrylamide and quaternary ammonium cationic monomers (dimethylaminoethylacrylate, DMAEA and dimethylaminoethylmethacrylate, DMAEM) has been carried out using both a block copolymeric surfactant (HB246) whose hydrophilic moiety is polyethylene oxide and whose hydrophobic moiety is poly(12 hydroxy stearic acid) and sorbitan monoleate (SMO). Our results indicate that the choice of surfactant influences strongly the

  15. 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.

  16. Gel polymer electrolytes based on polyacrylonitrile and a novel quaternary ammonium salt for dye-sensitized solar cells

    SciTech Connect

    Wang Guiqiang [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China) and Graduate School of Chinese Academy of Science, Beijing 100080 (China)]. E-mail: wgqiang@iccas.ac.cn; Zhou Xiaowen [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Li Mingyu [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Graduate School of Chinese Academy of Science, Beijing 100080 (China); Zhang Jinbo [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Kang Junjia [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Lin Yuan [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)]. E-mail: a1703@iccas.ac.cn; Fang Shibi [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Xiao Xurui [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2004-11-02

    Gel polymer electrolytes were prepared by incorporating polyacrylonitrile (PAN) in a mixture of polysiloxane with quaternary ammonium side groups (PSQAS), ethylene carbonate (EC), propylene carbonate (PC) and iodine. The influence of PAN content on the ionic conductivity of gel polymer electrolytes and the charge-transfer kinetic performance in counterelectrode-electrolyte interface was investigated. The dye-sensitized solar cell with the gel polymer electrolyte containing 5 wt.% PAN showed the best photovoltaic performance; a maximum incident photon conversion efficiency of 63% at 520 nm was obtained, the short-circuit photocurrent density (J{sub sc}), the open-circuit voltage (V{sub oc}) and the fill factor (FF) were 7 mA cm{sup -2}, 0.565 V and 0.65, respectively. The corresponding overall conversion efficiency ({eta}) is 4.3%.

  17. Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

    PubMed

    Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

    2013-04-12

    Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and ?-? interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples. PMID:23473515

  18. 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

  19. Liquid chromatography-tandem mass spectrometry detection of the quaternary ammonium compound mebezonium as an active ingredient in t61.

    PubMed

    Kirschbaum, Katrin M; Grellner, Wolfgang; Rochholz, Gertrud; Musshoff, Frank; Madea, Burkhard

    2011-03-01

    Quaternary ammonium compounds pose an analytical challenge. Mebezonium, a muscle-relaxing agent contained in veterinary euthanasia solution T61, was analyzed in body fluids, organs, and injection sites of a veterinarian by liquid chromatography-tandem mass spectrometry (LC-MS-MS) method. Additionally, embutramide and tetracaine, which are two other active ingredients contained in T61, methadone, xylazine, and analgesics were detected by LC-MS-MS and high-performance liquid chromatography-ultraviolet detection methods. For detection of mebezonium a solid-phase extraction (SPE) combined with ionpairing reagent heptafluorobutyric acid was developed. Separation was achieved on Phenomenex Synergi Hydro RP C(18) column combined with ammonium formate buffer and acetonitrile (pH 3.5). To enrich other drugs, liquid-liquid extraction procedures were used. Most of these drugs were separated on a Restek Allure PFP Propyl column using the mentioned mobile phase. Mebezonium and embutramide were detected in femoral vein serum in concentrations of 10.9 and 2.0 mg/L, respectively. The concentration of xylazine and methadone in serum was 2.0 and 0.4 mg/L, respectively. The LC-MS-MS method with SPE combined with an ion-pairing reagent allowed the quantitation of mebezonium. Methadone was detected in toxic concentrations and was, in combination with xylazine and T61, considered to be the cause of death. PMID:21396233

  20. Synthesis and thermotropic liquid crystalline properties of zwitterionic gemini surfactants containing a quaternary ammonium and a sulfate group.

    PubMed

    Zhou, Tianhua; Zhao, Jianxi

    2009-10-01

    A homologous series of novel zwitterionic gemini surfactants, N,N-dimethyl-N-[3-(alkyloxy)-2-sulfate-propyl]-alkylammonium (referred to as C(m)EOSAC(n)), were synthesized. One of the hydrophilic groups is a sulfate anion, and the other is an ammonium cation. Their thermotropic liquid crystalline properties were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and variable-temperature X-ray diffraction (XRD). The results were compared with those for bis(quaternary ammonium) gemini amphiphiles with counterions and catanionic surfactants without a spacer. The C(m)EOSAC(n)s were shown to display improved thermal stability and to form a stable smectic A liquid-crystalline phase over a wide temperature region (63+/-0.5 degrees C), which can be attributed to weakening the interactions between the surfactant headgroups. The XRD data confirmed that the two chains of molecules were arranged in a cis configuration with respect to the extended N-CH(2)-CH-SO(4) skeleton in both the solid lattice and the mesophases. In addition, the DSC results showed that the dissymmetry of the hydrophobic chains had a slight effect on the melting point and the clearing point of the C(m)EOSAC(n) compounds. The present investigation points the way to developing stable liquid crystalline materials using gemini-type surfactants. PMID:19564026

  1. The Effect of Continuous and Pulse Dose Ammonium Chloride Regimens on the Urine pH of Goats

    E-print Network

    Sprake, Philippa May

    2012-10-19

    and grass hay fed to goats, however, did not result in a significant difference in urine pH between the 2 groups.46 Variation in protein levels in feed has also not affected the acid- base status in cattle.58 Show goat diets commonly have ammonium... consecutive days followed by four days without treatment for three treatment periods. Ammonium chloride dosages were titrated to result in a urine pH of level) prior to commencing treatment regimens. Urine pH was evaluated once daily during...

  2. Synthesis, photophysical and antimicrobial activity of new water soluble ammonium quaternary benzanthrone in solution and in polylactide film.

    PubMed

    Staneva, Desislava; Vasileva-Tonkova, Evgenia; Makki, Mohamad Saleh I; Sobahi, Tariq Rashad; Abd?l-Rahman, Reda Mohamed; Asiri, Abdullah M; Grabchev, Ivo

    2015-02-01

    The synthesis of a new cationic water soluble fluorescent 1-[(7-oxo-7H-benzo[de]anthracen-3-ylcarbamoyl)-methyl]-triethylammonium chloride (B) has been described. Due to the presence of the quaternary amino group, the compound is soluble in water. Its photophysical characteristics in aqueous solution and organic solvents with different polarity have been determined using absorption and fluorescence spectroscopy. The photostability of compound B has been investigated in aqueous media. The newly synthesized compound has been tested in vitro for its antimicrobial activity against eight bacterial and two yeasts cultures. The results obtained suggest that the newly synthesized compound is effective in treating the relevant pathogens and is suitable in designing new effective antimicrobial preparations. The incorporation of the compound into thin polylactic acid film and its release into water solution has been also investigated. It was demonstrated that the compound released from the polymer polylactic acid matrix exhibited a prolonged good antibacterial activity. PMID:25596400

  3. Kinetics of emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride and acrylamide with gamma rays

    NASA Astrophysics Data System (ADS)

    Ge, Xuewu; Ye, Qiang; Xu, Xiangling; Zhang, Zhicheng; Sun, Qian

    1997-09-01

    Inverse emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride with acrylamide has been studied with gamma ray dilatometrically. Aqueous monomer solutions were emulsified in kerosene with a blend of two surfactants (Span80 and OP10). The gel effect is evident from the increase of the molecular weight with conversion and also from the percentage conversion versus time curves. Monomer reactivity ratios have been derived as rAM = 0.23 and rDMC = 1.40 at pH 6.8. Initial emulsions and final inverse latexes displayed the same broad size distribution. The effects of dose rate, concentration and composition of the monomer, emulsifier concentration, etc. on polymerization rate and intrinsic viscosity of polymer have been examined. The rate of polymerization ( Rp) can be represented by Rp ? D0.87[M] 1.37[E] 0.53. The overall activation activation energy for the rate of polymerization is 16.9 kJ/mol (32-55°C). Based on these experimental results, some aspects of the polymerization mechanism are discussed.

  4. Ammonium chloride inhibits autophagy of hepatocellular carcinoma cells through SMAD2 signaling.

    PubMed

    Sun, Ranran; Luo, Yonggang; Li, Juan; Wang, Qiongye; Li, Jingjing; Chen, Xiaolong; Guan, Kelei; Yu, Zujiang

    2015-02-01

    Autophagy is a cellular degradation process for the clearance of damaged or superfluous proteins and organelles, the recycling of which serves as an alternative energy source during periods of metabolic stress to maintain cell homeostasis and viability. The anti-necrotic function of autophagy is critical for tumorigenesis of many tumor cells, including hepatocellular carcinoma (HCC). However, the underlying mechanism is not clarified yet. Ammonium chloride (NH4Cl) is a well-known autophagy inhibitor, whereas its interaction with SMAD2 signaling pathway has not been reported previously. Here, we show that NH4Cl significantly inhibited rapamycin-induced autophagy in HCC cells through decreasing the levels of Beclin-1, autophagy-related protein 7 (ATG7), p62, and autophagosome marker LC3 and significantly decreased the level of phosphorylated SMAD2 in rapamycin-treated HCC cells. In order to find out whether NH4Cl may inhibit the autophagy in rapamycin-treated HCC cells through inhibition of SMAD2 signaling, we used transforming growth factor ?1 (TGF?1) to induce phosphorylation of SMAD2 in HCC cells. We found that induction of SMAD2 in HCC cells completely abolished the inhibitory effect of NH4Cl on rapamycin-induced autophagy in HCC cells, suggesting that NH4Cl inhibits autophagy of HCC cells through inhibiting SMAD2 signaling. PMID:25342595

  5. Surface chemical study on the covalent attachment of hydroxypropyltrimethyl ammonium chloride chitosan to titanium surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Xiaofen; Wang, Ling; Guo, Shengrong; Lei, Lei; Tang, Tingting

    2011-10-01

    An anti-microbial and bioactive coating could not only reduce the probability of infection related to titanium implants but also support the growth of surrounding osteogenic cells. Our previous study has showed that hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with a DS (degrees of substitution) of 18% had improved solubility and significantly higher antibacterial activities against three bacteria which were usually associated with infections in orthopaedics. In the current study, HACC with a DS of 18% coating was bonded to titanium surface by a three-step process. The titanium surface after each individual reaction step was analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection (ATR) of Fourier-transformed infrared (FT-IR) spectroscopy. The XPS results demonstrated that there were great changes in the atomic ratios of C/Ti, O/Ti, and N/Ti after each reaction step. The XPS high resolution and corresponding devolution spectra of carbon, oxygen, nitrogen, and titanium were also in good coordination with the anticipated reaction steps. Additionally, the absorption bands around 3365 cm -1 (-OH vibration), 1664 cm -1 (Amide I), 1165 cm -1 ( ?as, C-O-C bridge), and the broad absorption bands between 958 cm -1 and 1155 cm -1 (skeletal vibrations involving the C-O stretching of saccharide structure of HACC) verified that HACC was successfully attached to titanium surface.

  6. [Growth inhibition and mechanism of cetyltrimethyl ammonium chloride on Chlorella vulgaris].

    PubMed

    Xu, Yin; Ge, Fei; Tao, Neng-Guo; Zhu, Run-Liang; Wang, Na

    2009-06-15

    Growth inhibition of cetyltrimethyl ammonium chloride (CTAC), a cationic surfactants, on Chlorella vulgaris was investigated at batch culture in laboratory. Furthermore, the corresponding mechanisms were studied by the determination of absorption capacity, Zeta potential, activity of acid phosphatase and ultrastructure of algae. Results show that the growth inhibition by CATC is enhanced with its concentration increasing from 0.1 mg/L to 1 mg/L, and 96 h-EC50 of CTAC is 0.18 mg/L. In the presence of 0.3 mg/L CTAC in 8 d, the inhibition efficiency of biomass reaches 70.7%. Meanwhile, the absorption of nitrogen and iron is inhibited 83.9% and 86.2% respectively with Zeta potential of algae cell increasing from -12.5 mV to -6.7 mV. Furthermore, the relative activity of acid phosphatase declines to 23.1% at the same time. Plasmolysis, distortion of pyrenoid and swelling of lysosome is observed in the cell. Above phenomena indicates that CTAC increases the Zeta potential of algae cell and thus inhibites the absorption of nitrogen and iron. In addition, CTAC may affect the metabolism of phosphorus and change the ultrastructure of algae cell. PMID:19662866

  7. Adsorption kinetics of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride at oil-water interface

    NASA Astrophysics Data System (ADS)

    Wei, Xi-lian; Wang, Xiu-hong; Liu, Jie; Sun, De-zhi; Yin, Bao-lin; Wang, Xiu-jie

    2012-11-01

    Dynamic interfacial tension (DIT) between aqueous solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride (RnHTAC) and n-octane was measured using spinning drop method. The effects of RnHTAC concentration (the concentration below the CMC) and temperature on DIT have been investigated. The cause of the change of DIT with time has been discussed. The effective diffusion coefficient, Da, and the adsorption barrier, ?a, have been obtained with extended Word-Tordai equation. The results show that the higher the concentration of the surfactant is, the smaller the DIT will be and the lower the curve of the DIT, and the aqueous RnHTAC solutions follow a mixed diffusion-activation adsorption mechanism. With increase of RnHTAC concentration in the bulk solution, Da decreases and ?a increases. Da of aqueous R14HTAC solution decreases from 0.090 × 10-13 m2 s-1 to 0.081 × 10-13 m2 s-1 and ?a increases from 10.12 kJ mol-1 to 11.89 kJ mol-1, with the temperature increasing from 30 °C to 50 °C. This phenomenon indicates that the diffusion tendency becomes weak with the strengthening of the interaction between the surfactant molecules and that the thermo-motion of molecules benefits interface adsorption.

  8. Recognition of N-alkyl and N-aryl acetamides by N-alkyl ammonium resorcinarene chlorides.

    PubMed

    Beyeh, N Kodiah; Ala-Korpi, Altti; Cetina, Mario; Valkonen, Arto; Rissanen, Kari

    2014-11-10

    N-alkyl ammonium resorcinarene chlorides are stabilized by an intricate array of intra- and intermolecular hydrogen bonds that leads to cavitand-like structures. Depending on the upper-rim substituents, self-inclusion was observed in solution and in the solid state. The self-inclusion can be disrupted at higher temperatures, whereas in the presence of small guests the self-included dimers spontaneously reorganize to 1:1 host-guest complexes. These host compounds show an interesting ability to bind a series of N-alkyl acetamide guests through intermolecular hydrogen bonds involving the carbonyl oxygen (C=O) atoms and the amide (NH) groups of the guests, the chloride anions (Cl(-)) and ammonium (NH2(+)) cations of the hosts, and also through CH???? interactions between the hosts and guests. The self-included and host-guest complexes were studied by single-crystal X-ray diffraction, NMR titration, and mass spectrometry. PMID:25257765

  9. Dental plaque microcosm response to bonding agents containing quaternary ammonium methacrylates with different chain lengths and charge densities

    PubMed Central

    Zhou, Han; Li, Fang; Weir, Michael D.; Xu, Hockin H.K.

    2013-01-01

    Objectives Antibacterial bonding agents are promising to combat bacteria and caries at tooth-restoration margins. The objectives of this study were to incorporate new quaternary ammonium methacrylates (QAMs) to bonding agent and determine the effects of alkyl chain length (CL) and quaternary amine charge density on dental plaque microcosm bacteria response for the first time. Methods Six QAMs were synthesized with CL = 3, 6, 9, 12, 16, 18. Each QAM was incorporated into Scotchbond Multi-purpose (SBMP). To determine the charge density effect, dimethylaminododecyl methacrylate (DMAHDM, CL = 16) was mixed into SBMP at mass fraction = 0%, 2.5%, 5%, 7.5%, 10%. Charge density was measured using a fluorescein dye method. Dental plaque microcosm using saliva from ten donors was tested. Bacteria were inoculated on resins. Early-attachment was tested at 4 hours. Biofilm colony-forming units (CFU) were measured at 2 days. Results Incorporating QAMs into SBMP reduced bacteria early-attachment. Microcosm biofilm CFU for CL = 16 was 4 log lower than SBMP control. Charge density of bonding agent increased with DMAHDM content. Bacteria early-attachment decreased with increasing charge density. Biofilm CFU at 10% DMAHDM was reduced by 4 log. The killing effect was similarly-strong against total microorganisms, total streptococci, and mutans streptococci. Conclusions Increasing alkyl chain length and charge density of bonding agent was shown for the first time to decrease microcosm bacteria attachment and reduce biofilm CFU by 4 orders of magnitude. Novel antibacterial resins with tailored chain length and charge density are promising for wide applications in bonding, cements, sealants and composites to inhibit biofilms and caries. PMID:23948394

  10. Separation of aromatic carboxylic acids using quaternary ammonium salts on reversed-phase HPLC. 1. Separation behavior of aromatic carboxylic acids

    SciTech Connect

    Kawamura, K.; Okuwaki, A.; Verheyen, T.; Perry, G.J. [Tohoku University, Miyagi (Japan). Graduate School of Environmental Studies

    2006-02-15

    In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt has been investigated. The retention mechanism of aromatic carboxylic acids was discussed on the basis of both ion-pair partition model and ion-exchange model. The retention behavior of aromatic carboxylic acids possessing one (or two) carboxylic acid group(s) followed the ion-pair partition model, where linear free energy relationship was observed between the capacity factor and the extraction equilibrium constants of benzoic acid and naphthalene carboxylic acid. Besides, the retention behavior followed ion-exchange model with increasing the number of carboxylic acids, where the capacity factor of benzene polycarboxylic acids is proportional to the association constants between aromatic acids and quaternary ammonium ions calculated on the basis of an electrostatic interaction model.

  11. Insights into the transport of aqueous quaternary ammonium cations: a combined experimental and computational study.

    PubMed

    Sarode, Himanshu N; Lindberg, Gerrick E; Yang, Yuan; Felberg, Lisa E; Voth, Gregory A; Herring, Andrew M

    2014-02-01

    This study focuses on understanding the relative effects of ammonium substituent groups (we primarily consider tetramethylammonium, benzyltrimethylammonium, and tetraethylammonium cations) and anion species (OH(-), HCO3(-), CO3(2-), Cl(-), and F(-)) on ion transport by combining experimental and computational approaches. We characterize transport experimentally using ionic conductivity and self-diffusion coefficients measured from NMR. These experimental results are interpreted using simulation methods to describe the transport of these cations and anions considering the effects of the counterion. It is particularly noteworthy that we directly probe cation and anion diffusion with pulsed gradient stimulated echo NMR and molecular dynamics simulations, corroborating these methods and providing a direct link between atomic-resolution simulations and macroscale experiments. By pairing diffusion measurements and simulations with residence times, we were able to understand the interplay between short-time and long-time dynamics with ionic conductivity. With experiment, we determined that solutions of benzyltrimethylammonium hydroxide have the highest ionic conductivity (0.26 S/cm at 65 °C), which appears to be due to differences for the ions in long-time diffusion and short-time water caging. We also examined the effect of CO2 on ionic conductivity in ammonium hydroxide solutions. CO2 readily reacts with OH(-) to form HCO(-)3 and is found to lower the solution ionic conductivity by almost 50%. PMID:24437699

  12. Preparation and characterisation of anion exchangers with dihydroxy-containing alkyl substitutes in the quaternary ammonium functional groups.

    PubMed

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

    2014-01-01

    Novel poly(styrene-divinylbenzene) (PS-DVB) based anion exchangers having one and two (2,3-dihydroxypropyl) substitutes in the quaternary ammonium functional groups are prepared and characterised by ion chromatography (IC). The introduction of bulky and hydrophilic substitutes to the anion-exchange groups allows the elimination of non-ionic interactions between the polarisable anions and the aromatic rings from the matrix and the improvement of separation selectivity as compared with the traditional trimethylammonium (TMA) functionalised ion exchangers. The synthesis of the ion exchangers includes acylation of PS-DVB particles with acetic anhydride followed by reductive amination either with methylamine hydrochloride or dimethylamine and further alkylation with oxiranes under varied conditions. The ion exchange selectivity and separation efficiency of nine adsorbents having different structure of bonded groups, ion exchange capacity (9-98?equiv.g(-1)) or particle size is studied for model mixture of inorganic anions (F(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) using carbonate and hydroxide eluents. The adsorbents with more hydrophilic substitutes provided superior columns efficiencies and better peak symmetry as compared with analogues having hydrophobic functional groups. The calculated values of column efficiencies for polarisable NO3(-) and HPO4(2-) are 18,500 and 29,000N/m, respectively, for anion-exchanger, having N-methyl-N',N?-di-(2,3-dihydroxypropyl)ammonium groups which is significantly higher than 1800 and 12,000N/m obtained for these anions with anion exchanger bearing TMA functional groups. PMID:24309716

  13. Self-assembly and film stability of a micelle of a single-chain quaternary ammonium amphiphile containing azobenzene on mica

    Microsoft Academic Search

    Xueliang Hou; Lu Sun; Bo Zou; Lixin Wu

    2004-01-01

    The self-assembling behavior of a single-chain quaternary ammonium amphiphile bearing azobenzene (C12AzoC6N+) on freshly cleaved mica sheet has been investigated by atomic force microscopy (AFM) method. Confocal microscopic Raman spectra confirm the adsorption of the self-assembled monolayer structure. Ex-situ AFM reveals that C12AzoC6N+ forms branch-like stripes indicating the fusion and reorganization of the micelles during drying in air as the

  14. Separation of aromatic carboxylic acids using quaternary ammonium salts on reversed-phase HPLC. 2. Application for the analysis of Loy Yang coal oxidation products

    SciTech Connect

    Kawamura, K.; Okuwaki, A.; Verheyen, T.V.; Perry, G.J. [Tohoku University, Miyagi (Japan). Graduate School of Environmental Studies

    2006-07-01

    In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt was optimized using the solvent gradient method. This method was applied for the analysis of Loy Yang coal oxidation products. It was confirmed that the analytical data using this method were consistent with those determined using gas chromatography.

  15. Environmental assessment of an alkyl dimethyl benyzl ammonium chloride (ADBAC) based mollusicide using laboratory tests

    SciTech Connect

    Dobbs, M.G.; Cherry, D.S.; Scott, J.C. [Virginia Tech, Blacksburg, VA (United States); Petrille, J.C. [Betz Water Management Center, Trevose, PA (United States)

    1995-06-01

    A series of acute and chronic toxicity tests were conducted to estimate the potential environmental impact of n-alkyl dimethyl benzyl ammonium chloride (ADBAC) when used to control zebra mussels and other types of macrofouling organism in industrial cooling systems. The ADBAC-based molluscicide was tested as pure product and often detoxification with bentonite clay. Six flow-through acute tests were conducted to estimate the toxicity of ADBAC. In addition three chronic toxicity tests using Pimephales promelas, Daphnia magna and Selenastrum capricornutum were carried out to evaluate the efficacy of complexing the ADBAC-based molluscicide with a bentonite clay as a detoxification strategy. A 29-day CO{sub 2} Production test was also conducted to evaluate the biodegradability of the molluscicide. Of the six species tested in acute flow-through experiments, D. magna (LC{sub 50} = 0.02 mg ADBAC/L) was the most sensitive species followed by Mysidopsis bahia (LC{sub 50} = 0.08 mg ADBAC/L), Menidia beryllina (LC{sub 50} = 0.88 mg ADBAC/L), P. promelas (LC{sub 50} = 0.36 mg ADBAC/L), Cyprinodon variegatus (LC{sub 50} = 0.88 mg ADBAC/L), and Oncorhynchus mykiss (LC{sub 50} = 1.01 mg ADBAC/L). In the detoxification studies the three test species were exposed to treatment levels of: 0:0, 2.5:0, 2.5:25, 2.5:37.5, 2.5:50, 2.5:75, and 0:75 as mg/L ADBAC:clay. Bentonite clay was found to be an effective detoxification agent for this molluscicide at all treatment levels, except for the 2.5:25 treatment. In addition, a biodegradation study showed that the ADBAC-based molluscicide was readily biodegradable by unacclimated activated sludge microorganisms releasing 65.9% of the theoretical possible CO{sub 2} after 29 days.

  16. Nitric oxide-releasing quaternary ammonium-modified poly(amidoamine) dendrimers as dual action antibacterial agents.

    PubMed

    Worley, Brittany V; Slomberg, Danielle L; Schoenfisch, Mark H

    2014-05-21

    Herein we describe the synthesis of nitric oxide (NO)-releasing quaternary ammonium (QA)-functionalized generation 1 (G1) and generation 4 (G4) poly(amidoamine) (PAMAM) dendrimers. Dendrimers were modified with QA moieties of different alkyl chain lengths (i.e., methyl, butyl, octyl, dodecyl) via a ring-opening reaction. The resultant secondary amines were then modified with N-diazeniumdiolate NO donors to yield NO-releasing QA-modified PAMAM dendrimers capable of spontaneous NO release (payloads of ~0.75 ?mol/mg over 4 h). The bactericidal efficacy of individual (i.e., non-NO-releasing) and dual action (i.e., NO-releasing) QA-modified PAMAM dendrimers was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacteria. Bactericidal activity was found to be dependent on dendrimer generation, QA alkyl chain length, and bacterial Gram class for both systems. Shorter alkyl chains (i.e., methylQA, butylQA) demonstrated increased bactericidal activity against P. aeruginosa versus S. aureus for both generations, with NO release markedly enhancing overall killing. PMID:24797526

  17. 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.

  18. Efficacies of Sodium Hypochlorite and Quaternary Ammonium Sanitizers for Reduction of Norovirus and Selected Bacteria during Ware-Washing Operations

    PubMed Central

    Feliciano, Lizanel; Li, Jianrong; Lee, Jaesung; Pascall, Melvin A.

    2012-01-01

    Cross-contamination of ready-to-eat (RTE) foods with pathogens on contaminated tableware and food preparation utensils is an important factor associated with foodborne illnesses. To prevent this, restaurants and food service establishments are required to achieve a minimum microbial reduction of 5 logs from these surfaces. This study evaluated the sanitization efficacies of ware-washing protocols (manual and mechanical) used in restaurants to clean tableware items. Ceramic plates, drinking glasses and stainless steel forks were used as the food contact surfaces. These were contaminated with cream cheese and reduced-fat milk inoculated with murine norovirus (MNV-1), Escherichia coli K-12 and Listeria innocua. The sanitizing solutions tested were sodium hypochlorite (chlorine), quaternary ammonium (QAC) and tap water (control). During the study, the survivability and response to the experimental conditions of the bacterial species was compared with that of MNV-1. The results showed that current ware-washing protocols used to remove bacteria from tableware items were not sufficient to achieve a 5 log reduction in MNV-1 titer. After washing, a maximum of 3 log reduction in the virus were obtained. It was concluded that MNV-1 appeared to be more resistant to both the washing process and the sanitizers when compared with E. coli K-12 and L. innocua. PMID:23227163

  19. Characterisation and discrimination of various types of lac resin using gas chromatography mass spectrometry techniques with quaternary ammonium reagents.

    PubMed

    Sutherland, K; del Río, J C

    2014-04-18

    A variety of lac resin samples obtained from artists' suppliers, industrial manufacturers, and museum collections were analysed using gas chromatography mass spectrometry (GCMS) and reactive pyrolysis GCMS with quaternary ammonium reagents. These techniques allowed a detailed chemical characterisation of microgram-sized samples, based on the detection and identification of derivatives of the hydroxy aliphatic and cyclic (sesquiterpene) acids that compose the resin. Differences in composition could be related to the nature of the resin, e.g. wax-containing (unrefined), bleached, or aged samples. Furthermore, differences in the relative abundances of aliphatic hydroxyacids appear to be associated with the biological source of the resin. The diagnostic value of newly characterised lac components, including 8-hydroxyacids, is discussed here for the first time. Identification of derivatised components was aided by AMDIS deconvolution software, and discrimination of samples was enhanced by statistical evaluation of data using principal component analysis. The robustness of the analyses, together with the minimal sample size required, make these very powerful approaches for the characterisation of lac resin in museum objects. The value of such analyses for enhancing the understanding of museum collections is illustrated by two case studies of objects in the collection of the Philadelphia Museum of Art: a restorer's varnish on a painting by Luca Signorelli, and a pictorial inlay in an early nineteenth-century High Chest by George Dyer. PMID:24642395

  20. In situ x-ray diffraction studies of alkyl quaternary ammonium montmorillonite in a CO(2) environment.

    PubMed

    Thompson, M R; Balogh, M P; Speer, R L; Fasulo, P D; Rodgers, W R

    2009-01-28

    An in situ study was conducted using an x-ray diffractometer and a specially designed high pressure cell to examine the effects of carbon dioxide at different pressures and temperatures on three different modified montmorillonite species. These organoclays possessed organic pillars of quaternary ammonium surfactant with either one, two, or three long (C(16)-C(18)) alkyl chains attached to expand the galleries of the clay mineral. The three clay species were tested between 50 degrees C and 200 degrees C with carbon dioxide pressures between 0.1 and 8.4 MPa. Under these conditions, the three organoclays exhibited marked differences in their basal spacing depending on the surfactant used. The physical state of the intercalated surfactant was found to be of critical importance, with no changes in basal spacing noted until the organic component began to melt, in spite of CO(2) being present. A pressure effect was also noted which delayed melting of the surfactants as the pressure of the system increased. In all cases, further cation exchange with residual sodium cation present in the galleries was observed in the presence of CO(2) and above the melting state of the surfactant. The study included examination of the effect of rapid depressurization on the clay structure, which produced only a small change in basal spacing. PMID:19191402

  1. UV-Vis spectrophotometric studies of self-oxidation/dissociation of quaternary ammonium permanganates (QAP) - impact of solvent polarity.

    PubMed

    Bank, Suraj Prakash; Guru, Partha Sarathi; Dash, Sukalyan

    2015-05-01

    Self-oxidation/dissociation of some quaternary ammonium permanganates (QAPs), such as cetyltrimethylammonium permanganate (CTAP) and tetrabutylammonium permanganate (TBAP), have been studied spectrophotometrically in six different organic solvent media of different polarities wherein the compounds show good solubility and stability. The optical densities of the substrates at zero time (ODo) and first-order rate constants of dissociation (k1) have been determined from their successive scanning for 40min. At comparable experimental conditions, absorption capabilities of the substrates are compared from the ODo values in various organic media; the stability of the solutions is compared from the successive scan spectra in those media. The ODo values and the k1 values have been plotted against some solvent parameters to understand their effects on the absorbance and reactivity of the QAPs. These data are also subjected to multiple regression analysis to explain the influence of various solvent parameters on the ion-pairing properties of the substrates, thus elucidating their effects on the process of self-oxidation/dissociation of the substrates. PMID:25699691

  2. Quaternary ammonium salt containing soybean oil: an efficient nanosize gene delivery carrier for halophile green microalgal transformation.

    PubMed

    Akbari, Fariba; Yari Khosroushahi, Ahmad; Yeganeh, Hamid

    2015-01-01

    Dunaliella salina, a halophile green microalga, is considered a robust photobioreactor and a remarkable cost beneficial system for the production of therapeutic recombinant proteins. In this study, with low overall cost, a proper cationic lipid was synthesized from renewable soybean oil as an efficient gene delivery carrier for D. salina cells to create appropriate protein-producing transformed cell lines. To obtain an effective carrier, quaternary ammonium salt containing soybean oil (QASSO) was synthesized through the ring opening reaction of the epoxy groups of epoxidized soybean oil with diethylamine. QASSO was characterized using nuclear magnetic resonance and Fourier-transform infrared instruments. QASSO was used to prepare nanolipoplex construct using plasmid DNA molecules containing green fluorescent protein (GFP) as reporter gene. These nanolipoplexes (QASSO-pGFP, N/P=3) and QASSO had diameter of 63.62 and 110.63 nm, and zeta potential of -68.89 and 48.25 mV at pH 7.0, respectively. Results indicated the GFP gene expression and cytoplasmic accumulation of GFP protein in the transformants after incubation under desirable conditions for 48 h and 1 week. The transformation efficiency was quantitatively assayed by flow cytometry, which yielded transformations of 58.87% and 48.34% for QASSO and 38.32% and a negligible percentage for Polyfect® after 48 h and 1 week incubation, respectively. PMID:25451567

  3. Capillary electrophoresis-mass spectrometry for the analysis of quaternary ammonium herbicides.

    PubMed

    Núñez, Oscar; Moyano, Encarnación; Galceran, Maria Teresa

    2002-10-18

    Conditions for the simultaneous determination of the three herbicides paraquat, diquat and difenzoquat and the two plant growth regulators chlormequat and mepiquat by pressure-assisted capillary electrophoresis coupled to mass spectrometry (ion-trap) using electrospray as ionisation source have been established. A 200 mM formic acid-ammonium formate buffer solution at pH 3.0 with 50% of methanol was used as carrier electrolyte. Some capillary electrophoresis-mass spectrometry parameters such as sheath liquid and sheath gas flow-rates, sheath liquid composition, electrospray voltage andthe CE capillary position were optimised. The MS and MS-MS spectra of positive ions were studied in order to obtain structural information for the confirmation of the identity. The use of labelled standards allowed to confirm fragment ions assignation. The detection limits, based on a signal-to-noise ratio of 3:1, were between 0.5 and 2.5 mg l(-1) with hydrodynamic injection (10 s) and between 1 and 10 microg l(-1) with elecrokinetic injection (20 s, 10 kV) using standards in ultrapure water. Quality parameters such as linearity and run-to-run precision (n=6) were established. Quantitation was carried out using labelled standards. The method has been applied to the analysis of contaminated irrigation water and spiked mineral water samples. PMID:12458941

  4. Nutrient Leaching in Undisturbed Cores of an Acidic Sandy Podosol Following Simultaneous Potassium Chloride and Di-Ammonium Phosphate Application

    Microsoft Academic Search

    Ian R Phillips; Edward D Burton

    2005-01-01

    In south-east Queensland, Australia, extensive areas of sandy soils (Podosols) with shallow (<1 m) watertables are used for\\u000a exotic pine tree production. Despite concerns that surface-applied fertilisers (di-ammonium phosphate (DAP) and potassium\\u000a chloride (KCl)) may be contributing to a decline in local groundwater quality, published information on nutrient leaching\\u000a in these Podosols is scarce. Large (0.3 m i.d. ×0.85 m long) undisturbed soil cores

  5. Survival of Adhering Staphylococci during Exposure to a Quaternary Ammonium Compound Evaluated by Using Atomic Force Microscopy Imaging?

    PubMed Central

    Crismaru, Mihaela; Asri, Lia A. T. W.; Loontjens, Ton J. A.; Krom, Bastiaan P.; de Vries, Joop; van der Mei, Henny C.; Busscher, Henk J.

    2011-01-01

    Effects of a quaternary ammonium compound (QAC) on the survival of adhering staphylococci on a surface were investigated using atomic force microscopy (AFM). Four strains with different minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) for the QAC were exposed to three different concentrations of the QAC in potassium phosphate buffer (0.5×, 1×, and 2× MBC) while adhering to glass. Adhering staphylococci were repeatedly imaged with AFM in the contact mode, and the cell surface was found to wrinkle upon progressive exposure to the QAC until bacteria disappeared from the substratum. Higher concentrations of QAC yielded faster wrinkling and the disappearance of bacteria during imaging. Two slime-producing staphylococcal strains survived longer on the surface than two non-slime-producing strains despite similar MICs and MBCs. All staphylococci adhering in unscanned areas remained adhering during exposure to QAC. Since MICs and MBCs did not relate to bacterial cell surface hydrophobicities and zeta potentials, survival on the surface is probably not determined by the direct interaction of QAC molecules with the cell surface. Instead, it is suggested that the pressure of the AFM tip assists the incorporation of QAC molecules in the membrane and enhances their bactericidal efficacy. In addition, the prolonged survival under pressure from slime-producing strains on a surface may point to a new protective role of slime as a stress absorber, impeding the incorporation of QAC molecules. The addition of Ca2+ ions to a QAC solution yielded longer survival of intact, adhering staphylococci, suggesting that Ca2+ ions can impede the exchange of membrane Ca2+ ions required for QAC incorporation. PMID:21876063

  6. Review and phylogenetic analysis of qac genes that reduce susceptibility to quaternary ammonium compounds in Staphylococcus species

    PubMed Central

    Ussery, David; Nielsen, Lene N.; Ingmer, Hanne

    2015-01-01

    The qac genes of Staphylococcus species encode multidrug efflux pumps: membrane proteins that export toxic molecules and thus increase tolerance to a variety of compounds such as disinfecting agents, including quaternary ammonium compounds (for which they are named), intercalating dyes and some antibiotics. In Stapylococcus species, six different plasmid-encoded Qac efflux pumps have been described, and they belong to two major protein families. QacA and QacB are members of the Major Facilitator Superfamily, while QacC, QacG, QacH, and QacJ all belong to the Small Multidrug Resistance (SMR) family. Not all SMR proteins are called Qac and the reverse is also true, which has caused confusion in the literature and in gene annotations. The discovery of qac genes and their presence in various staphylococcal populations is briefly reviewed. A sequence comparison revealed that some of the PCR primers described in the literature for qac detection may miss particular qac genes due to lack of DNA conservation. Despite their resemblance in substrate specificity, the Qac proteins belonging to the two protein families have little in common. QacA and QacB are highly conserved in Staphylococcus species, while qacA was also detected in Enterococcus faecalis, suggesting that these plasmid-born genes have spread across bacterial genera. Nevertheless, these qacA and qacB genes are quite dissimilar to their closest homologues in other organisms. In contrast, SMR-type Qac proteins display considerable sequence variation, despite their short length, even within the Staphylococcus genus. Phylogenetic analysis of these genes identified similarity to a large number of other SMR members, found in staphylococci as well as in other genera. A number of phylogenetic trees of SMR Qac proteins are presented here, starting with genes present in S. aureus and S. epidermidis, and extending this to related genes found in other species of this genus, and finally to genes found in other genera. PMID:25883793

  7. Highly fluorescent C-dots obtained by pyrolysis of quaternary ammonium ions trapped in all-silica ITQ-29 zeolite

    NASA Astrophysics Data System (ADS)

    Baldovi, Herme G.; Valencia, Susana; Alvaro, Mercedes; Asiri, Abdullah M.; Garcia, Hermenegildo

    2015-01-01

    C-dots obtained in the homogeneous phase may exhibit a broad particle size distribution. The formation of C-dots within nanometric reaction cavities could be a methodology to gain control on their size distribution. Among the various possibilities, in the present work, the cavities of small pore size zeolites have been used to confine C-dots generated by the pyrolysis of the organic structure directing agent present in the synthesis of these crystalline aluminosilicates. To explore this methodology, ITQ-29 zeolite having a Linde type A (LTA) structure was prepared as pure silica with 4-methyl-2,3,6,7-tetrahydro-1H,5H-pyrido[3.2.1-ij]quinolinium as the organic structure directing agent. Pyrolysis under an inert atmosphere at 550 °C of a pure-silica ITQ-29 sample (cubic particles of 4 ?m edge) renders a highly fluorescent zeolite containing about 15 wt% of the carbonised residue. While another small pore zeolite, ITQ-12 (ITW), also renders photoluminescent C-dots under similar conditions, medium or large pore zeolites, such as silicalite (MFI) or pure silica Beta (BEA), failed to produce fluorescent powders under analogous thermal treatment and only decomposition and complete removal of the corresponding quaternary ammonium ion templates was observed for these zeolites. The dissolution of the pyrolysed ITQ-29 zeolite framework and the extraction of the carbon residue with ethyl acetate have allowed the characterisation of C-dots with particle sizes between 5 and 12 nm and a photoluminescence quantum yield of 0.4 upon excitation at 350 nm that is among the highest reported for non-surface functionalized C-dots. Photoluminescence varies with the excitation wavelength and is quenched by oxygen. Pyrolysed ITQ-29 powders can act as fluorescent oxygen sensors.

  8. Diverse inhibitory actions of quaternary ammonium cholinesterase inhibitors on Torpedo nicotinic ACh receptors transplanted to Xenopus oocytes

    PubMed Central

    Olivera-Bravo, Silvia; Ivorra, Isabel; Morales, Andrés

    2007-01-01

    Background and purpose: This work was aimed at comparing and analysing the effects and mechanisms of action of the quaternary ammonium cholinesterase inhibitors (QChEIs) BW284c51, decamethonium and edrophonium, on nicotinic ACh receptor (nAChR) function. Experimental approach: nAChRs purified from Torpedo electroplax were transplanted to oocytes and currents elicited by ACh (IACh) either alone or in presence of these QChEIs were recorded. Key results: None of the QChEIs, by itself, elicited changes in membrane conductance; however, when co-applied with ACh, all of them decreased IACh in a concentration-dependent way. The mechanisms of nAChR inhibition were different for these QChEIs. BW284c51 blockade was non-competitive and voltage-dependent, although it also affected the nH of the dose-response curve. By contrast, decamethonium and edrophonium inhibition, at –60 mV, was apparently competitive and did not modify either desensitisation or nH. Decamethonium effects were voltage-independent and washed out slowly after its removal; by contrast, edrophonium blockade had strong voltage dependence and its effects disappeared quickly after its withdrawal. Analysis of the voltage-dependent blockade indicated that BW284c51 bound to a shallow site into the channel pore, whereas edrophonium bound to a deeper locus. Accordingly, additive inhibitory effects on IACh were found among any pairs of these QChEIs. Conclusions and implications: The tested QChEIs bound to the nAChR at several and different loci, which might account for their complex inhibitory behaviour, acting both as allosteric effectors and, in the case of BW284c51 and edrophonium, as open channel blockers. PMID:17572698

  9. Highly fluorescent C-dots obtained by pyrolysis of quaternary ammonium ions trapped in all-silica ITQ-29 zeolite.

    PubMed

    Baldovi, Herme G; Valencia, Susana; Alvaro, Mercedes; Asiri, Abdullah M; Garcia, Hermenegildo

    2015-02-01

    C-dots obtained in the homogeneous phase may exhibit a broad particle size distribution. The formation of C-dots within nanometric reaction cavities could be a methodology to gain control on their size distribution. Among the various possibilities, in the present work, the cavities of small pore size zeolites have been used to confine C-dots generated by the pyrolysis of the organic structure directing agent present in the synthesis of these crystalline aluminosilicates. To explore this methodology, ITQ-29 zeolite having a Linde type A (LTA) structure was prepared as pure silica with 4-methyl-2,3,6,7-tetrahydro-1H,5H-pyrido[3.2.1-ij]quinolinium as the organic structure directing agent. Pyrolysis under an inert atmosphere at 550 °C of a pure-silica ITQ-29 sample (cubic particles of 4 ?m edge) renders a highly fluorescent zeolite containing about 15 wt% of the carbonised residue. While another small pore zeolite, ITQ-12 (ITW), also renders photoluminescent C-dots under similar conditions, medium or large pore zeolites, such as silicalite (MFI) or pure silica Beta (BEA), failed to produce fluorescent powders under analogous thermal treatment and only decomposition and complete removal of the corresponding quaternary ammonium ion templates was observed for these zeolites. The dissolution of the pyrolysed ITQ-29 zeolite framework and the extraction of the carbon residue with ethyl acetate have allowed the characterisation of C-dots with particle sizes between 5 and 12 nm and a photoluminescence quantum yield of 0.4 upon excitation at 350 nm that is among the highest reported for non-surface functionalized C-dots. Photoluminescence varies with the excitation wavelength and is quenched by oxygen. Pyrolysed ITQ-29 powders can act as fluorescent oxygen sensors. PMID:25516465

  10. Survival of adhering staphylococci during exposure to a quaternary ammonium compound evaluated by using atomic force microscopy imaging.

    PubMed

    Crismaru, Mihaela; Asri, Lia A T W; Loontjens, Ton J A; Krom, Bastiaan P; de Vries, Joop; van der Mei, Henny C; Busscher, Henk J

    2011-11-01

    Effects of a quaternary ammonium compound (QAC) on the survival of adhering staphylococci on a surface were investigated using atomic force microscopy (AFM). Four strains with different minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) for the QAC were exposed to three different concentrations of the QAC in potassium phosphate buffer (0.5×, 1×, and 2× MBC) while adhering to glass. Adhering staphylococci were repeatedly imaged with AFM in the contact mode, and the cell surface was found to wrinkle upon progressive exposure to the QAC until bacteria disappeared from the substratum. Higher concentrations of QAC yielded faster wrinkling and the disappearance of bacteria during imaging. Two slime-producing staphylococcal strains survived longer on the surface than two non-slime-producing strains despite similar MICs and MBCs. All staphylococci adhering in unscanned areas remained adhering during exposure to QAC. Since MICs and MBCs did not relate to bacterial cell surface hydrophobicities and zeta potentials, survival on the surface is probably not determined by the direct interaction of QAC molecules with the cell surface. Instead, it is suggested that the pressure of the AFM tip assists the incorporation of QAC molecules in the membrane and enhances their bactericidal efficacy. In addition, the prolonged survival under pressure from slime-producing strains on a surface may point to a new protective role of slime as a stress absorber, impeding the incorporation of QAC molecules. The addition of Ca(2+) ions to a QAC solution yielded longer survival of intact, adhering staphylococci, suggesting that Ca(2+) ions can impede the exchange of membrane Ca(2+) ions required for QAC incorporation. PMID:21876063

  11. Levels of ammonium, sulfate, chloride, calcium, and sodium in snow and ice from southern Greenland

    Microsoft Academic Search

    Eurybiades Busenberg; Chester C. Langway

    1979-01-01

    Chemical analysis of surface snows and dated ice core samples from Dye 3, Greenland, suggests that the ammonium cation is a major constituent in all samples and that the annual ammonium levels present in the south Greenland samples have varied from 3.3 to 26.3 mug\\/kg between the seventeenth century and the present time. The annual range of 1974-1975 surface samples

  12. Increased serum triglycerides and reduced HDL cholesterol in male rats after intake of ammonium chloride for 3 weeks

    PubMed Central

    2013-01-01

    Background Previous data suggested that intake of sodas and other acid beverages might be associated with increased levels of serum triglycerides, lowered HDL cholesterol, and increased formation of mono unsaturated fatty acids, which are the preferred ones for triglyceride synthesis. The present work is an extension of these studies. Methods Thirty male rats were divided into 3 groups. All groups were given the same food, but various beverages: water (W), ammonium chloride, 200 mmol/L (AC), or sodium bicarbonate, 200 mmol/L (SB). Serum triglycerides, HDL cholesterol, and the fatty acid distribution in total serum lipids were determined. Delta9-desaturase in serum lipids was estimated by the ratio of palmitoleic to palmitic acid, and by the oleic/stearic acid ratio. Correlation and ANOVA were used to study associations and group differences. Results After 3 weeks, the AC group had higher triglyceride concentration and higher Delta9 desaturase indexes, but lower serum HDL and body weight as compared with the SB and W groups. In each of the groups, the oleic acid/stearic acid ratio correlated positively with serum triglycerides; in the pooled group the correlation coefficient was r?=?0.963, p<0.01. Conclusions Rats ingesting ammonium chloride as compared with sodium bicarbonate responded with increased desaturase indexes, increased serum triglycerides, and lowered HDL cholesterol concentration, thereby possibly contributing to explain the increased triglyceride concentration previously observed in subjects with a frequent intake of acid beverages, such as sodas containing carbonic acid, citric acid, and phosphoric acid. PMID:23800210

  13. Radiation Stability of Benzyl Tributyl Ammonium Chloride Towards Technetium-99 Extraction

    SciTech Connect

    Jared Horkley; Audrey Roman; Keri Campbell; Ana Nunez; Amparo Espartero

    2013-02-01

    A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning process, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, low nitric acid concentration in the aqueous phase of a UREX based process will co-extract U(VI) and Tc(VII) by tri-n-butyl phosphate (TBP). Technetium (Tc-99) is recognized to be one of the most abundant, long-lived radiotoxic isotopes in UNF (half-life, t1/2 = 2.13 × 105 years), and as such, it is targeted in UNF separation strategies for isolation and encapsulation in solid waste forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flow sheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste forms for ultimate disposal. Furthermore, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macrocompounds such as crown-ethers, aza-crown ethers, and resorcinarenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO4- by benzyltributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand’s matrix conditions and concentration, as well as varying the organic phase composition (i.e., diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using external Co-60 source. Post-irradiation solvent extraction measurements will be discussed.

  14. A review of methods for the analysis of orphan and difficult pesticides: glyphosate, glufosinate, quaternary ammonium and phenoxy acid herbicides, and dithiocarbamate and phthalimide fungicides.

    PubMed

    Raina-Fulton, Renata

    2014-01-01

    This article reviews the chromatography/MS methodologies for analysis of pesticide residues of orphan and difficult chemical classes in a variety of sample matrixes including water, urine, blood, and food. The review focuses on pesticide classes that are not commonly included in multiresidue analysis methods such as highly polar or ionic herbicides including glyphosate, glufosinate, quaternary ammonium, and phenoxy acid herbicides, and some of their major degradation or metabolite products. In addition, dithiocarbamate and phthalimide fungicides, which are thermally unstable and have stability issues in some solvents or sample matrixes, are also examined due to their special needs in residue analysis. PMID:25145125

  15. Effect of a Novel Quaternary Ammonium Methacrylate Polymer (QAMP) on Adhesion and Antibacterial Properties of Dental Adhesives

    PubMed Central

    Pupo, Yasmine M.; Farago, Paulo Vitor; Nadal, Jessica M.; Simão, Luzia C.; Esmerino, Luís Antônio; Gomes, Osnara M. M.; Gomes, João Carlos

    2014-01-01

    This study investigated the resin–dentin bond strength (?TBS), degree of conversion (DC), and antibacterial potential of an innovative adhesive system containing a quaternary ammonium methacrylate polymer (QAMP) using in situ and in vitro assays. Forty-two human third molars were flattened until the dentin was exposed and were randomly distributed into three groups of self-etching adhesive systems: Clearfil™ SE Bond containing 5% QAMP (experimental group), Clearfil™ Protect Bond (positive control) and Clearfil™ SE Bond (negative control). After light curing, three 1 mm-increments of composite resin were bonded to each dentin surface. A total of thirty of these bonded teeth (10 teeth per group) was sectioned to obtain stick-shaped specimens and tested under tensile stress immediately, and after 6 and 12 months of storage in distilled water. Twelve bonded teeth (4 teeth per group) were longitudinally sectioned in a mesio-to-distal direction to obtain resin-bonded dentin slabs. In situ DC was evaluated by micro-Raman spectroscopy. In vitro DC of thin films of each adhesive system was measured using Fourier transform infrared spectroscopy. In vitro susceptibility tests of these three adhesive systems were performed by the minimum inhibitory/minimum bactericidal concentration (MIC/MBC) assays against Streptococcus mutans, Lactobacillus casei, and Actinomyces naeslundii. No statistically significant difference in ?TBS was observed between Clearfil™ SE Bond containing 5% QAMP and Clearfil™ SE Bond (p > 0.05) immediately, and after 6 and 12 months of water storage. However Clearfil™ Protect Bond showed a significant reduction of ?TBS after 12 months of storage (p = 0.039). In addition, QAMP provided no significant change in DC after incorporating into Clearfil™ SE Bond (p > 0.05). Clearfil™ SE Bond containing 5% QAMP demonstrated MIC/MBC values similar to the positive control against L. casei and A. naeslundii and higher than the negative control for all evaluated bacterial strains. The use of QAMP in an adhesive system demonstrated effective bond strength, a suitable degree of conversion, and adequate antibacterial effects against oral bacteria, and may be useful as a new approach to provide long-lasting results for dental adhesives. PMID:24853131

  16. Effect of quaternary ammonium cation loading and pH on heavy metal sorption to Ca bentonite and two organobentonites.

    PubMed

    Oyanedel-Craver, Vinka A; Smith, James A

    2006-09-21

    Sorption of four heavy metals (Pb, Cd, Zn and Hg) to calcium bentonite (Ca bentonite), hexadecyltrimethylammonium bentonite (HDTMA bentonite) and benzyltriethylammonium bentonite (BTEA bentonite) was measured as a function of the quaternary ammonium cation (QAC) loading at 25, 50 and 100% of the clay's cation-exchange capacity (CEC). The effects of pH on the surface charge of the clays and heavy metal sorption were also measured. Sorption of Cd, Pb, and Zn was non-linear and sorption of all three metals by HDTMA and BTEA bentonites decreased as the QAC loading increased from 25 to 100%. In most cases, sorption of these metals to 25% BTEA and 25% HDTMA bentonite was similar to or greater than sorption to Ca bentonite. Hg sorption was linear for both HDTMA and BTEA bentonite. No significant effect on Hg sorption was observed with increasing QAC loading on BTEA bentonite. However, an increase of Hg sorption was detected with increasing QAC loading on HDTMA bentonite. This behavior suggests that a process different than cation exchange was the predominant Hg sorption mechanism. Cd, Pb, and Zn sorption decreased with pH. However, this effect was stronger for Cd and Pb than Zn. Hg sorption varied inversely with pH. QAC loading affected the surface charge of the clays. Twenty-five and 50% loading of BTEA cations increased the negative charge on the clay's surface relative to the untreated clay, without affecting the zero point of charge (ZPC) of the clay. Increased QAC loading on HDTMA bentonite causes the surface charge to become more positive and the ZPC increased. One hundred percent of HDTMA bentonite maintained a positive surface charge over the range of pH values tested. The organoclays studied have considerable capacity for heavy metal sorption. Given that prior studies have demonstrated the strong sorption capacity of organoclays for nonionic organic pollutants, it is likely that organoclays can be useful sorbents for the treatment of effluent streams containing both organic contaminants and heavy metals. PMID:16647204

  17. Functionalized ionic liquids based on quaternary ammonium cations with two ether groups as new electrolytes for Li/LiFePO4 secondary battery

    NASA Astrophysics Data System (ADS)

    Jin, Yide; Zhang, Jianhao; Song, Jianzhi; Zhang, Zhengxi; Fang, Shaohua; Yang, Li; Hirano, Shin-ichi

    2014-05-01

    New functionalized ILs based on quaternary ammonium cations with two ether groups and bis(trifluoromethanesulfonyl)imide (TFSA-) anion are synthesized and characterized. Physical and electrochemical properties, including melting point, thermal stability, viscosity, conductivity and electrochemical stability are investigated for these ILs. All these ILs are liquids at room temperature except N,N-diethyl-N,N-bis(2-ethoxyethyl)ammonium TFSA (N22(2o2)(2o2)-TFSA, Tm = 29.7 °C), and the viscosities of N-methyl-N-ethyl-N-(2-methoxyethyl)-N-(2-ethoxyethyl)ammonium TFSA (N12(2o1)(2o2)-TFSA) and N-methyl-N-ethyl-N,N-bis(2-ethoxyethyl)ammonium TFSA (N12(2o2)(2o2)-TFSA) are 68.0 cP and 63.0 cP at 25 °C, respectively. N-Methyl-N,N-diethyl-N-(2-methoxyethyl)ammonium TFSA (DEME-TFSA) and five ILs with lower viscosity are chosen to dissolve 0.6 mol kg-1 of LiTFSA as IL electrolytes without additive for lithium battery. Lithium plating and striping on Ni electrode can be observed in these IL electrolytes, and cycle performances of lithium symmetrical cells are also investigated for these IL electrolytes. Li/LiFePO4 cells using these IL electrolytes without additives have good cycle property at the current rate of 0.1 C, and the N-methyl-N-ethyl-N,N-bis(2-methoxyethyl)ammonium TFSA (N12(2o1)(2o1)-TFSA) and N12(2o2)(2o2)-TFSA electrolytes own better rate property than DEME-TFSA electrolyte.

  18. Biocide comparison: Aldehyde versus mixture of aldehyde and quaternary amine

    SciTech Connect

    Prasad, R. [Champion Technologies, Inc., Houston, TX (United States)

    1994-12-31

    Glutaraldehyde and quaternary ammonium chloride salts are widely used biocides in oil field systems to control microbiologically influenced corrosion (MIC). These biocides and others were evaluated for their efficacy to control sessile and planktonic sulfate reducing bacteria (SRB) and aerobic bacteria. The efficacy of these biocides was then compared. In addition to laboratory evaluation, all the biocides were evaluated against SRB and acid producing bacteria in two different field waters. It was found that the blend containing aldehyde and quaternary amino was, in general, a more effective biocide than either glutaraldehyde or quaternary amine alone.

  19. Fire performance and decay resistance of solid wood and plywood treated with quaternary ammonia compounds and common fire retardants

    Microsoft Academic Search

    Evren Terzi; S. Nami Kartal; Robert H. White; Katsumi Shinoda; Yuji Imamura

    2011-01-01

    In this study, the fire performance and decay resistance of solid wood and plywood treated with quaternary ammonia compounds\\u000a (didecyl dimethyl ammonium chloride (DDAC) and didecyl dimethyl ammonium tetrafluoroborate (DBF)) were compared with the performance\\u000a of untreated control specimens and specimens treated with common fire retardants ((monoammonium phosphate (MAP), diammonium\\u000a phosphate (DAP) and ammonium sulphate (AS)). Test specimens were treated

  20. Synthesis and structural studies of a new class of quaternary ammonium salts, which are derivatives of cage adamanzane type aminal 1, 3, 6, 8-tetraazatricyclo[4.3.1.13,8]undecane (TATU)

    PubMed Central

    2011-01-01

    Background Novel mono N-alkyl quaternary ammonium salts (3a-f) were prepared using the Menschutkin reaction from the cage adamanzane type aminal 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecane (TATU) and alkyl iodides, such as methyl, ethyl, propyl, butyl, pentyl and hexyl iodide (2a-f), in dry acetonitrile at room temperature. Results The structures of these new quaternary ammonium salts were established using various spectral and electrospray ionization mass spectrometry (ESI-MS) analyses. Compound (3b) was also analyzed using X-ray crystallography. Conclusion It was noted that alkyl chain length did not significantly affect the reaction because all employed alkyl iodide electrophiles reacted in a similar fashion with the aminal 1 to produce the corresponding mono N-quaternary ammonium salts, which were characterized by spectroscopic and analytical techniques. PMID:21933409

  1. 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.

  2. Selective Detection of Carbohydrates and Their Peptide Conjugates by ESI-MS Using Synthetic Quaternary Ammonium Salt Derivatives of Phenylboronic Acids

    NASA Astrophysics Data System (ADS)

    Kijewska, Monika; Kuc, Adam; Kluczyk, Alicja; Waliczek, Mateusz; Man-Kupisinska, Aleksandra; Lukasiewicz, Jolanta; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2014-06-01

    We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

  3. Corrosion mitigation of N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride as inhibitor on mild steel.

    PubMed

    Sangeetha, Y; Meenakshi, S; SairamSundaram, C

    2015-01-01

    The biopolymer N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride (HTACC) was synthesised and its influence as a novel corrosion inhibitor on mild steel in 1M HCl was studied using gravimetric and electrochemical experiments. The compound obtained was characterised using FTIR and NMR studies. The inhibition efficiency increased with the increase in concentration and reached a maximum of 98.9% at 500 ppm concentration. Polarisation studies revealed that HTACC acts both as anodic and cathodic inhibitor. Electrochemical impedance studies confirmed that the inhibition is through adsorption on the metal surface. The extent of inhibition exhibits a negative trend with increase in temperature. Langmuir isotherm provides the best description on the adsorption nature of the inhibitor. SEM analysis indicated the presence of protective film formed by the inhibitor on the metal surface. PMID:25450546

  4. Synthesis, growth and characterization of non linear optical Bisthiourea ammonium chloride single crystals by slow evaporation technique

    NASA Astrophysics Data System (ADS)

    Ilango, E.; Rajasekaran, R.; Shankar, K.; Krishnan, S.; Chithambaram, V.

    2014-11-01

    A new semi-organic nonlinear optical crystal of Bisthiourea Ammonium Chloride (BTAC) has been grown by slow evaporation technique. The crystal system and lattice parameters were determined from X-ray diffraction. Fourier Transform Infrared (FTIR) studies confirm the various functional groups present in the grown crystal. The transmittance and absorbance of electromagnetic radiation is studied through UV-Visible spectrum. The thermal behavior of the grown crystals has been investigated by TG/DTA analysis. The dielectric constant and dielectric loss has been studied as a function of frequency for various temperatures and the result were discussed in detail. The SEM analysis was also done and it revealed the surface morphology of BTAC crystal. The second harmonic generation has been confirmed by the Kurtz powder test and it is found to be 1.4 times more than that of KDP crystal.

  5. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on low-weight greige and bleached cotton nonwovens in different aqueous environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has shown the adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) on cotton nonwovens is dependent on pretreatment of the substrate, more specifically whether it is greige or bleached fabric. In this work we examine the effect of varying the chemical and physical propert...

  6. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  7. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations using UV/vis spectroscopy. Results show greige...

  8. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    NASA Astrophysics Data System (ADS)

    Supeno, Daik, Rusli; El-Sheikh, Said M.

    2014-09-01

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  9. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    SciTech Connect

    Supeno [Cenderawasih University, Jayapura, Papua, Indonesia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Daik, Rusli, E-mail: rusli@ukm.edu.my [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); El-Sheikh, Said M. [Nano-Structured Materials Division, Advanced Materials Department, Central Metallurgical Research and Development Institute, Cairo (Egypt)

    2014-09-03

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  10. The optical constants of several atmospheric aerosol species - Ammonium sulfate, aluminum oxide, and sodium chloride

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Pollack, J. B.; Khare, B. N.

    1976-01-01

    An investigation is conducted of problems which are related to a use of measured optical constants in the simulation of the optical constants of real atmospheric aerosols. The techniques of measuring optical constants are discussed, taking into account transmission measurements through homogeneous and inhomogeneous materials, the immersion of a material in a liquid of a known refractive index, the consideration of the minimum deviation angle of prism measurement, the interference of multiply reflected light, reflectivity measurements, and aspects of mathematical analysis. Graphs show the real and the imaginary part of the refractive index as a function of wavelength for aluminum oxide, NaCl, and ammonium sulfate. Tables are provided for the dispersion parameters and the optical constants.

  11. Optimizing the concentration of quaternary ammonium dimethacrylate monomer in bis-GMA/TEGDMA dental resin system for antibacterial activity and mechanical properties.

    PubMed

    Liang, Xiaoxu; Söderling, Eva; Liu, Fang; He, Jingwei; Lassila, Lippo V J; Vallittu, Pekka K

    2014-05-01

    Four novel quaternary ammonium dimethacrylate monomers named IMQ (side alkyl chain length from 12 to 18) were synthesized with the aim to synthesize dental resin with antibacterial activity. All of IMQs were added into bis-GMA/TEGDMA dental resin system with a series of mass ratio (5, 10, and 20 wt%), double bond conversion (DC), flexural strength (FS), modulus of elasticity (FM) and biofilm formation inhibitory effect were studied. According to the results of DC, FS, FM, and the biofilm inhibitory effect, IMQ-16 containing polymer had the best comprehensive properties, and the optimal concentration of IMQ-16 in bis-GMA/TEGDMA dental resin would be in the range of 5-10 wt%. PMID:24449028

  12. AGING EFFECTS ON THE PROPERTIES OF IMIDAZOLIUM, QUATERNARY AMMONIUM, PYRIDINIUM AND PYRROLIDINIUM-BASED IONIC LIQUIDS USED IN FUEL AND ENERGY PRODUCTION

    SciTech Connect

    Fox, E.

    2013-08-13

    Ionic liquids are often cited for their excellent thermal stability, a key property for their use as solvents and in the chemical processing of biofuels. However, there has been little supporting data on the long term aging effect of temperature on these materials. Imizadolium, quaternary ammonium, pyridinium, and pyrrolidnium-based ionic liquids with the bis(trifluoromethylsulfonyl)imide and bis(perfluoroethylsulfonyl)imide anions were aged for 2520 hours (15 weeks) at 200?C in air to determine the effects of an oxidizing environment on their chemical structure and thermal stability over time. It was found that the minor changes in the cation chemistry could greatly affect the properties of the ILs over time.

  13. DFT studies of the formation of furanoid derivatives of ammonium chlorides.

    PubMed

    Wieli?ska, Justyna; Liberek, Beata; Nowacki, Andrzej

    2015-03-01

    B3LYP/6-31+G** level computations were performed on the formation of ammonium salts during the reaction of (S)-1,4-anhydro-5-chloro-2,3,5-trideoxypentitol (1) (2S,5S)-2,5-anhydro-6-chloro-1,3,4,6-tetradeoxyhexitol (2) and methyl 5-chloro-2,3,5-trideoxy-?-D-pentofuranoside (3) with ammonia in order to describe the reaction pathway in detail. All the structures were fully optimized in the gas phase, in chloroform and water. In addition, the gas phase activation barrier heights were estimated at B3LYP/6-311++G**, MPWIK/6-31+G**, MPWIK/6-311++G** and MP2/6-311++G(2d,2p)//MPWIK/6-31+G** levels of theory. All the calculations in solvents were performed the using polarizable continuum model (PCM) and the B3LYP functional with the 6-31+G** basis set. A detailed description of all the stationary points is presented, and the conformational behavior of the five-membered ring is discussed in the gas phase and in the solvents. The conversion of the reactant complexes into ion pairs is accompanied by a strong energy decrease in the gas phase and in all the solvents. The overall process is strongly unfavorable in the gas phase, but takes place readily in high-polarity solvents. PMID:25562663

  14. Influence of ammonium, nitrate, and chloride on solution pH and ion uptake by ageratum and salvia in hydroponic culture

    Microsoft Academic Search

    Byoung Ryong Jeong; Chiwon W. Lee

    1996-01-01

    The influence of nitrogen (N) forms and chloride (Cl) on solution pH and ion uptake in the hydroponic culture of Ageratum houstonianum [ammonium (NH4 )?tolerant] and Salvia splendens (NH4 ?sensitive) for a period of 216 hours was investigated. The pH of the hydroponic solution (initially 6.50) containing either NH4 or NH4 +nitrate (NO3 ) was drastically lowered (3.08), whereas that

  15. A family of single-isomer, dicationic cyclodextrin chiral selectors for capillary electrophoresis: mono-6(A)-ammonium-6(C)-butylimidazolium-?-cyclodextrin chlorides.

    PubMed

    Dai, Yun; Wang, Shuye; Zhou, Jie; Tang, Jian; Tang, Weihua

    2013-03-01

    The first member of the single-isomer, dicationic cyclodextrin (CD) family, 6(A)-ammonium-6(C)-butylimidazolium-?-cyclodextrin chlorides (AMBIMCD), has been synthesized, analytically characterized, and used to separate a variety of acidic enantiomers and amino acids by CE. Starting from mono-6(A)-azido-?-cyclodextrin, the cationic imidazolium and ammonium moieties were subsequently introduced onto primary ring of ?-cyclodextrin via nucleophilic addition and Staudinger reaction. The analytically pure AC regio-isomer CD was further obtained via column chromatography. This dicationic CD exhibited excellent enantioselectivities for selected analytes at concentration as low as 0.5 mM, which were even better than those of its mono-imidazolium or ammonium-substitued counterpart CDs at 10 equivalent concentrations. The effective mobilities of all studied analytes were found to decrease with the concentration of AMBIMCD. Inclusion complexation in combination with eletrostatic interactions seemed to account for the enhanced chiral discrimination process. PMID:23335062

  16. The effect of ammonium chloride and urea application on soil bacterial communities closely related to the reductive transformation of pentachlorophenol.

    PubMed

    Yu, Huan-Yun; Wang, Yong-kui; Chen, Peng-cheng; Li, Fang-bai; Chen, Man-jia; Hu, Min

    2014-05-15

    Pentachlorophenol (PCP) is widely distributed in the soil, and nitrogen fertilizer is extensively used in agricultural production. However, studies on the fate of organic contaminants as affected by nitrogen fertilizer application have been rare and superficial. The present study aimed to examine the effect of ammonium chloride (NH4Cl) and urea (CO(NH2)2) application on the reductive transformation of PCP in a paddy soil. The study showed that the addition of low concentrations of NH4Cl/CO(NH2)2 enhanced the transformation of PCP, while the addition of high concentrations of NH4Cl/CO(NH2)2 had the opposite effect. The variations in the abundance of soil microbes in response to NH4Cl/CO(NH2)2 addition showed that both NH4Cl and CO(NH2)2 had inhibitory effects on the growth of dissimilatory iron-reducing bacteria (DIRB) of the genus Comamonas. In contrast, for the genus Shewanella, low concentrations of NH4Cl inhibited growth, and high concentrations of NH4Cl enhanced growth, whereas all concentrations of CO(NH2)2 showed enhancement effects. In addition, consistent patterns of variation were found between the abundances of dechlorinating bacteria in the genus Dehalobacter and PCP transformation rates under NH4Cl/CO(NH2)2 addition. In conclusion, nitrogen application produced variations in the structure of the soil microbial community, especially in the abundance of dissimilatory iron-reducing bacteria and dechlorinating bacteria, which, in turn, affected PCP dechlorination. PMID:24662270

  17. An instrument for semi-continuous monitoring of the size-distribution of nitrate, ammonium, sulphate and chloride in aerosol

    NASA Astrophysics Data System (ADS)

    ten Brink, Harry; Otjes, René; Jongejan, Piet; Slanina, Sjaak

    An instrument was developed for semi-continuous measurement of the size-distribution of submicron nitrate, ammonium, sulphate and chloride. Novel in the instrumentation is the size-classification, which is realised with a pre-separator that consists of a set of four parallel impactors. The cut-off diameters of the impactors are at 0.18, 0.32, 0.56 and 1.0 ?m. Aerosols smaller than the associated cut-off size pass the respective impactor and arrive in the detector. The manifold with impactors contains two additional lines, one open line and one containing a filter that removes all aerosols. This latter line provides an on-line field-blank. The sample air-flow is automatically switched by wide-bore ball valves to one of the six sampling lines for a period of 20 min; a measuring cycle thus takes 2 h. Down-stream of the pre-separator the sampling and automated on-line analysis of the transmitted aerosol is accomplished with a "MARGA". In this instrument steam condensation is used to grow the aerosol. The droplets formed are collected in a cyclone that drains to wet-chemical analysis systems. A wet-denuder between pre-separator and collector removes interfering gases, like nitric acid and ammonia. This enables artefact-free and thus representative semi-continuous measurement of the size-distribution of the semi-volatile (ammonium) nitrate. The novel MARGA-sizer was first used in a 1 week field-test. After modifications it was then deployed in a monitoring campaign of 2 months in the summer of 2002, at the top level of the meteo-tower of Cabauw in the centre of the Netherlands. The high location, 200 m, was chosen to obtain data on ammonium nitrate that are minimally affected by surface emissions of ammonia. The data coverage over the period was over 60%; failure of the instrumentation was mainly associated with spells of extreme solar heating of the tower and associated high temperatures inside. The average concentration of nitrate was 2.6 ?g m -3, which was very similar to the value interpolated from data in the national network. The mass concentration of submicron nitrate was 2.0 ?g m -3, of which 46% was in particles smaller than 0.32 ?m. To put this in perspective: the concentration of submicron sulphate was similar to that of nitrate, while 53% was in particles smaller than 0.32 ?m. The ion balance showed that the compounds were present as the fully neutralised salts. Quite large diurnal variations were observed for nitrate, with a surprising maximum in the afternoon. The size-distribution of the semi-volatile nitrate was rather constant over a daily cycle.

  18. In vitro and in vivo antimicrobial activity of covalently coupled quaternary ammonium silane coatings on silicone rubber

    Microsoft Academic Search

    Bart Gottenbos; Henny C. van der Mei; Flip Klatter; Paul Nieuwenhuis; Henk J. Busscher

    2002-01-01

    Biomaterial-centered infection is a dreaded complication associated with the use of biomedical implants. In this paper, the antimicrobial activity of silicone rubber with a covalently coupled 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) coating was studied in vitro and in vivo. Gram-positive Staphylococcus aureus ATCC 12600, Staphylococcus epidermidis HBH2 102, and Gram-negative Escherichia coli O2K2 and Pseudomonas aeruginosa AK1 were seeded on silicone rubber

  19. Theoretical problems associated with the use of acetic anhydride as a co-solvent for the non-aqueous titration of hydrohalides of organic bases and quaternary ammonium salts.

    PubMed

    Völgyi, Gergely; Béni, Szabolcs; Takács-Novák, Krisztina; Görög, Sándor

    2010-01-01

    A potentiometric titration study of organic base hydrohalides and quaternary ammonium salts using perchloric acid as the titrant and a mixture of acetic anhydride and acetic acid as the solvent was carried out and the titration mixture was analysed by NMR in order to clarify the chemistry of the reactions involved. It was found that in contrast to the general belief the formation of acetyl halides and titratable free acetate ion does not take place prior to the titration but NMR spectra proved the formation of acetyl halides in the course of the titration. This observation and the fact that the shape of the titration curves depends on the nature of the hydrohaloic acid bound to the base or of the anion in the quaternary ammonium salts led to the conclusion that the titrating agent is acetyl perchlorate formed in situ during the titration. Equations of the reactions involved in the titration process are shown in the paper. PMID:19682817

  20. In Vitro Antibacterial Activity of a Novel Resin-Based Pulp Capping Material Containing the Quaternary Ammonium Salt MAE-DB and Portland Cement

    PubMed Central

    Zhang, Hongchen; Zhou, Wei; Ban, Jinghao; Wei, Jingjing; Liu, Yan; Gao, Jing; Chen, Jihua

    2014-01-01

    Background Vital pulp preservation in the treatment of deep caries is challenging due to bacterial infection. The objectives of this study were to synthesize a novel, light-cured composite material containing bioactive calcium-silicate (Portland cement, PC) and the antimicrobial quaternary ammonium salt monomer 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB) and to evaluate its effects on Streptococcus mutans growth in vitro. Methods The experimental material was prepared from a 2?1 ratio of PC mixed with a resin of 2-hydroxyethylmethacrylate, bisphenol glycerolate dimethacrylate, and triethylene glycol dimethacrylate (4?3?1) containing 5 wt% MAE-DB. Cured resin containing 5% MAE-DB without PC served as the positive control material, and resin without MAE-DB or PC served as the negative control material. Mineral trioxide aggregate (MTA) and calcium hydroxide (Dycal) served as commercial controls. S. mutans biofilm formation on material surfaces and growth in the culture medium were tested according to colony-forming units (CFUs) and metabolic activity after 24 h incubation over freshly prepared samples or samples aged in water for 6 months. Biofilm formation was also assessed by Live/Dead staining and scanning electron microscopy. Results S. mutans biofilm formation on the experimental material was significantly inhibited, with CFU counts, metabolic activity, viability staining, and morphology similar to those of biofilms on the positive control material. None of the materials affected bacterial growth in solution. Contact-inhibition of biofilm formation was retained by the aged experimental material. Significant biofilm formation was observed on MTA and Dycal. Conclusion The synthesized material containing HEMA-BisGMA-TEGDMA resin with MAE-DB as the antimicrobial agent and PC to support mineralized tissue formation inhibited S. mutans biofilm formation even after aging in water for 6 months, but had no inhibitory effect on bacteria in solution. Therefore, this material shows promise as a pulp capping material for vital pulp preservation in the treatment of deep caries. PMID:25389975

  1. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

    PubMed Central

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan

    2014-01-01

    Summary The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (M w/M n, 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (M n up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (f PA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). PMID:25161738

  2. Evaluation of aqueous and alcohol-based quaternary ammonium sanitizers for inactivating Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes on peanut and pistachio shells.

    PubMed

    McEgan, Rachel; Danyluk, Michelle D

    2015-05-01

    This study evaluated the efficacy of aqueous (aQUAT) and isopropyl alcohol-based quaternary ammonium (ipQUAT) sanitizers for reducing Salmonella spp., Escherichia coli O157:H7, or Listeria monocytogenes populations on peanut and pistachio shell pieces. Inoculated nutshells were mixed with QUAT sanitizers, water, or 70% ethanol and enumerated immediately or after incubation at 30 °C for 48 h. None of the treatments had any immediate effect on Salmonella or E. coli O157:H7 populations on the peanut or pistachio shells. L. monocytogenes populations declined immediately on the peanut and pistachio shells treated with aQUAT or ipQUAT. After incubation, Salmonella and E. coli O157:H7 populations increased significantly on the water- or aQUAT-treated peanut and pistachio shells. L. monocytogenes populations also increased significantly on the water- or aQUAT-treated peanut shells, but levels did not change on the water-treated pistachio shells and levels were just above the limit of detection on the aQUAT-treated pistachio shells. After treatment with ipQUAT and 48-h incubation, Salmonella and E. coli O157:H7 populations decreased to or below the limit of detection on both shell types; L. monocytogenes populations remained at or below the limit of detection on both shell types. PMID:25583342

  3. Bifunctional quaternary ammonium compounds to inhibit biofilm growth and enhance performance for activated carbon air-cathode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Nan; Liu, Yinan; An, Jingkun; Feng, Cuijuan; Wang, Xin

    2014-12-01

    The slow diffusion of hydroxyl out of the catalyst layer as well as the biofouling on the surface of cathode are two problems affecting power for membrane-less air-cathode microbial fuel cells (MFCs). In order to solve both of them simultaneously, here we simply modify activated carbon air-cathode using a bifunctional quaternary ammonium compound (QAC) by forced evaporation. The maximum power density reaches 1041 ± 12 mW m-2 in an unbuffered medium (0.5 g L-1 NaCl), which is 17% higher than the control, probably due to the accelerated anion transport in the catalyst layer. After 2 months, the protein content reduced by a factor of 26 and the power density increases by 33%, indicating that the QAC modification can effectively inhibit the growth of cathodic biofilm and improve the stability of performance. The addition of NaOH and QAC epoxy have a negative effect on power production due to the clogging of pores in catalyst layer.

  4. Scanning force microscopy of circular and linear plasmid DNA spread on mica with a quaternary ammonium salt.

    PubMed Central

    Schaper, A; Pietrasanta, L I; Jovin, T M

    1993-01-01

    Scanning force microscopy (SFM) offers the potential for subnanometer resolution in the investigation of nucleic acids, proteins, and their complexes. SFM is not bound by the requirement of classical transmission electron microscopy (TEM) for contrast enhancement through shadow casting or negative staining. A primary challenge, however, has been the reproducible fixation of samples on an atomically flat surface such as mica. We have developed a method for the routine imaging by SFM of supercoiled, relaxed, and linearized plasmid DNA, immobilized on freshly cleaved mica through the spreading action of benzyldimethylalkylammonium chloride (BAC) at micromolar concentrations. A reproducibly high yield of well-spread, dispersed molecules is obtained and background contamination is minimal. The contour lengths of the relaxed and linearized molecules imaged in air agree well with the helical rise (3.4 A/bp) of B-DNA in solution. We have also introduced the use of quantitative image analysis of SFM images to determine apparent molecular width and height over the entire molecular path. Images PMID:8290363

  5. Preparation of cross-linked magnetic chitosan with quaternary ammonium and its application for Cr(VI) and P(V) removal.

    PubMed

    Yao, Wei; Rao, Pinhua; Lo, Irene M C; Zhang, Wenqi; Zheng, Wenrui

    2014-12-01

    Pollutants that exist in anionic species are issues of concern in water treatment. Compared to cationic pollutants, the removal of anionic pollutants by adsorption is more difficult because most adsorbents carry predominantly negative charges in neutral and alkaline environments. In this study, a cross-linked chitosan derivative with quaternary ammonium and magnetic properties (QM-chitosan) was prepared and employed to remove chromium (VI) and phosphorus (V) (Cr(VI) and P(V)) from aqueous environments. The QM-chitosan was characterized by Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), energy dispersive X-ray (SEM-EDX) and zeta potential. Batch experiments show that QM-chitosan can effectively remove Cr(VI) and P(V), and the main mechanism was believed to be electrostatic interaction. A pseudo second-order model was fitted to describe the kinetic processes of Cr(VI) and P(V) removal. The adsorption isotherms of both Cr(VI) and P(V) on the QM-chitosan were well fitted by the Langmuir isotherm equation. The saturated adsorption capacity of P(V) (2.783 mmol/g) was found to be higher than that of Cr(VI) (2.323 mmol/g), resulting from the size of the H(2)PO(4)(-) ions being smaller than that of the HCrO(4)(-) ions. However, the theoretical calculation and experimental results showed that QM-chitosan had a stronger affinity for Cr(VI) than P(V). The adsorption-desorption of the QM-chitosan was evaluated, and high regeneration rates were demonstrated. PMID:25499485

  6. Importance of N source on heat stress tolerance due to the accumulation of proline and quaternary ammonium compounds in tomato plants.

    PubMed

    Rivero, R M; Ruiz, J M; Romero, L M

    2004-11-01

    Proline and quaternary ammonium compounds (QAC), in addition to being N-rich, are known to accumulate in plants under different environmental stress conditions. The accumulation of N-rich compounds in plants has been shown to confer stress resistance. The aim of our work is two-fold: first, to study the influence of temperature on proline, QAC, and choline metabolism in tomato leaves; and second, to investigate the relationship between N source applied (NO3- or NH4+) and thermal stress resistance in these plants. To do this, experiments were conducted at three different temperatures (10 degrees C, 25 degrees C, 35 degrees C); at each temperature half of the plants received NO3-, and the other half received NH4+. At 35 degrees C the plants had the lowest biomass production with respect to 25 degrees C (optimal temperature) and 10 degrees C (cold stress), suggesting that tomato plants were most affected by heat stress. At 35 degrees C, there were also high levels of choline and proline due to the activation of Delta1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT), and simultaneous inhibition of proline dehydrogenase (PDH) and proline oxidase (PO). However, plants with NH4+ as the N source exhibited reduced growth with respect to the plants fed with NO3-. This is interesting because, under heat stress (35 degrees C), biomass production, as well as proline and choline accumulation, in NH4+ fed plants was higher than in NO3- fed plants. From this, we concluded that tomato plants fed with NH4+ as the N source show higher tolerance to heat stress (35 degrees C) than plants fed with NO3-. PMID:15570475

  7. Facile preparation of magnetic 2-hydroxypropyltrimethyl ammonium chloride chitosan/Fe3O4/halloysite nanotubes microspheres for the controlled release of ofloxacin.

    PubMed

    Wang, Qin; Zhang, Junping; Mu, Bin; Fan, Ling; Wang, Aiqin

    2014-02-15

    Magnetic microspheres, 2-hydroxypropyltrimethyl ammonium chloride chitosan/Fe3O4/halloysite nanotubes/ofloxacin (HACC/Fe3O4/HNTs/OFL), for the controlled release of OFL were prepared by in situ crosslinking with glutaraldehyde in the spray-drying process. The magnetic microspheres were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and a magnetometer. Various parameters influencing the encapsulation efficiency, drug loading and in vitro controlled release properties of the magnetic microspheres for OFL were also studied. Many stripes were formed and some tubular HNTs could be seen at higher magnification on the surface of the HACC/Fe3O4/HNTs/OFL magnetic microspheres. The magnetic microspheres show superparamagnetic property and fast magnetic response. The encapsulation efficiency and the cumulative release of OFL are closely related to HACC concentration, HNTs contents and crosslinking density. The release of OFL follows the first-order kinetics. PMID:24507359

  8. Ammonium chloride salting out extraction/cleanup for trace-level quantitative analysis in food and biological matrices by flow injection tandem mass spectrometry.

    PubMed

    Nanita, Sergio C; Padivitage, Nilusha L T

    2013-03-20

    A sample extraction and purification procedure that uses ammonium-salt-induced acetonitrile/water phase separation was developed and demonstrated to be compatible with the recently reported method for pesticide residue analysis based on fast extraction and dilution flow injection mass spectrometry (FED-FI-MS). The ammonium salts evaluated were chloride, acetate, formate, carbonate, and sulfate. A mixture of NaCl and MgSO4, salts used in the well-known QuEChERS method, was also tested for comparison. With thermal decomposition/evaporation temperature of <350°C, ammonium salts resulted in negligible ion source residual under typical electrospray conditions, leading to consistent method performance and less instrument cleaning. Although all ammonium salts tested induced acetonitrile/water phase separation, NH4Cl yielded the best performance, thus it was the preferred salting out agent. The NH4Cl salting out method was successfully coupled with FI/MS/MS and tested for fourteen pesticide active ingredients: chlorantraniliprole, cyantraniliprole, chlorimuron ethyl, oxamyl, methomyl, sulfometuron methyl, chlorsulfuron, triflusulfuron methyl, azimsulfuron, flupyrsulfuron methyl, aminocyclopyrachlor, aminocyclopyrachlor methyl, diuron and hexazinone. A validation study was conducted with nine complex matrices: sorghum, rice, grapefruit, canola, milk, eggs, beef, urine and blood plasma. The method is applicable to all analytes, except aminocyclopyrachlor. The method was deemed appropriate for quantitative analysis in 114 out of 126 analyte/matrix cases tested (applicability rate=0.90). The NH4Cl salting out extraction/cleanup allowed expansion of FI/MS/MS for analysis in food of plant and animal origin, and body fluids with increased ruggedness and sensitivity, while maintaining high-throughput (run time=30s/sample). Limits of quantitation (LOQs) of 0.01mgkg(-1) (ppm), the 'well-accepted standard' in pesticide residue analysis, were achieved in >80% of cases tested; while limits of detection (LODs) were typically in the range of 0.001-0.01mgkg(-1) (ppm). A comparison to a well-established HPLC/MS/MS method was also conducted, yielding comparable results, thus confirming the suitability of NH4Cl salting out FI/MS/MS for pesticide residue analysis. PMID:23473245

  9. Infrared band intensities in ammonium hydroxide and ammonium salts

    NASA Technical Reports Server (NTRS)

    Sethna, P. P.; Downing, H. D.; Pinkley, L. W.; Williams, D.

    1978-01-01

    We have applied Kramers-Kronig analysis to reflection spectra to determine the optical constants of ammonium hydroxide and of aqueous solutions of ammonium chloride and bromide. From considerations of the absorption indices k(nu) we conclude that ammonium hydroxide consists of a solution of NH3 in water, in which NH3 molecules are hydrogen bonded to neighboring water molecules. The spectrum of ammonium hydroxide differs from the spectra of ammonium salts, in which bands characteristic of NH4(+) ions are prominent. The existence of ammonium hydroxide as an aerosol in planetary atmospheres is briefly discussed

  10. The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions.

    PubMed

    Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad

    2015-04-01

    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R(2) value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 ± 9 to 102.67 ± 6 mg/g. PMID:25617870

  11. Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride)

    PubMed Central

    Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

    2012-01-01

    Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 ? cm2 and 0.83, respectively. PMID:24958543

  12. Selective encapsulation of chloride ions within novel cage host complexes in the presence of equimolar amounts of chloride and bromide ions.

    PubMed

    Ichikawa, K; Izumi, M; Goto, D; Ito, N

    2001-12-01

    Four macrotricyclic cage hosts which feature four positive binding sites oriented toward the center of the intramolecular cavity are presented as promising candidates for anion receptors and they have been expected to play a important role in the selective encapsulation of the halide ion Cl- or Br . The complementarity between a macrotricyclic quaternary ammonium ion and Cl- was achieved by fine-tuning of the four ammonium nitrogen atoms and the endocyclic methylene groups. The cage hosts [R4N4(C5H10)4(C6H12)2]4+ (abbreviated as [556]) showed perfect encapsulation of all chloride ions in acetonitrile at 0 < r= ([Cl-]o/[[556

  13. Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment

    Microsoft Academic Search

    D. Rose; S. S. Gunthe; E. Mikhailov; G. P. Frank; U. Dusek; M. O. Andreae; U. Pöschl

    2008-01-01

    Experimental and theoretical uncertainties in the measurement of cloud condensation nuclei (CCN) with a continuous-flow thermal-gradient CCN counter from Droplet Measurement Technologies (DMT-CCNC) have been assessed by model calculations and calibration experiments with ammonium sulfate and sodium chloride aerosol particles in the diameter range of 20-220 nm. Experiments have been performed in the laboratory and during field measurement campaigns, covering

  14. The preparation of quaternary ammonium-based ionic liquid containing a cyano group and its properties in a lithium battery electrolyte

    Microsoft Academic Search

    Minato Egashira; Shigeto Okada; Jun-ichi Yamaki; Diego Alejandro Dri; Francesco Bonadies; Bruno Scrosati

    2004-01-01

    A room temperature ionic liquid consisting of N,N,N,N-cyanomethyl trimethyl ammonium (CTMA) cation and bis(trifluoromethane sulfone)imide (TFSI) anion was newly synthesized, and its electrochemical properties were investigated. This ionic liquid has a melting point of 35°C and an order of conductivity of 10?4Scm?1. Lithium deposition\\/dissolution tests in 0.2moldm?3 LiTFSI\\/CTMATFSI electrolytes showed an improved cycle behavior compared with that of a Li

  15. Analysis of residual products in triethylbenzylammonium chloride by HPLC. Study of the retention mechanism.

    PubMed

    Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

    2006-04-01

    The control of industrial products for minimization of their impact on the environment and human health requires the development of specific analysis methods. Information provided by these methods about toxic components, by-products, and other derivatives may also be useful to reduce the possible impact of industrial products. The studied compound in this paper, triethylbenzylammonium chloride (TEBA), is mainly used in industrial synthesis. This quaternary compound and its residual products coming from quaternization reaction (benzyl chloride, benzaldehyde, and benzyl alcohol) are analyzed by HPLC. The separation is based on control of the silanophilic contribution to TEBA retention because of the quaternary nature of this compound. The effect of the three buffers (sodium acetate, ammonium acetate, and sodium formate) and their concentrations in the chromatographic behavior of the quaternary compound is examined. The buffer cation and anion regulate TEBA retention. Also, the concentration of the quaternary compound is another parameter that had influence in some aspects of its chromatographic behavior (e.g., retention and symmetry). The proposed method is applied to TEBA synthesis along, with the formation and removal of impurities with the results compared with those obtained for the quaternary compound benzalkonium chloride. PMID:16620516

  16. High mass accuracy in-source collision-induced dissociation tandem mass spectrometry and multi-step mass spectrometry as complementary tools for fragmentation studies of quaternary ammonium herbicides.

    PubMed

    Núñez, Oscar; Moyano, Encarnación; Galceran, Maria Teresa

    2004-08-01

    Fragmentation studies using both an ion-trap mass analyzer and a hybrid quadrupole time-of-flight (Q-TOF) mass spectrometer were performed in order to establish the fragmentation pathways of organic molecules. A general strategy combining MSn data (n = 1-4) in an ion-trap analyzer with tandem mass spectrometry and in-source collision-induced dissociation tandem mass spectrometry (CID MS/MS) in a Q-TOF instrument was applied. The MSn data were used to propose a tentative fragmentation pathway following genealogical relationships. When several assignments were possible, MS/MS and in-source CID MS/MS (Q-TOF) allowed the elemental compositions of the fragments to be confirmed. Quaternary ammonium herbicides (quats) were used as test compounds and their fragmentation pathways were established. The elemental composition of the fragments was confirmed using the TOF analyzer with relative errors <0.0023 Da. Some fragments previously reported in the literature were reassigned taking advantage of the high mass resolution and accuracy of the Q-TOF instrument, which made it possible to solve losses where nitrogen was involved. PMID:15329839

  17. Analysis of quaternary ammonium compounds in estuarine sediments by LC-ToF-MS: very high positive mass defects of alkylamine ions provide powerful diagnostic tools for identification and structural elucidation

    PubMed Central

    Li, Xiaolin; Brownawell, Bruce J.

    2009-01-01

    A sensitive and robust method of analysis for quaternary ammonium compounds (QACs) in marine sediments is presented. Methods for extraction, sample purification, and HPLC-Time-of-Flight-MS analysis were optimized, providing solutions to problems associated with analysis of QACs, such as dialkyldimethylammonium (DADMAC) and benzalkonium (BAC) compounds experienced previously. Recognized in this study are the exceptionally high positive mass defects characteristic of alkylammonium or protonated alkylamine ions. No alternative and chemically-viable elemental formulas exist within 25.2 mDa when the number of double bond equivalents is low, effectively allowing facile discrimination of this compound class in complex mixtures. Accurate mass measurements of diagnostic collision induced dissociation fragment ions and heavy isotope peaks were obtained and also seen to be uniquely heavy compared to other elemental formulae. In the case of BACs, the ability to resolve masses of alkylamine fragment ions is greater than it is for molecular ions, opening up a wide range of potential applications. The power of utilizing a combination of approaches is illustrated with the identification of non-targeted DADMAC C8:C8 and C8:C10, two widely used biocides previously unreported in environmental samples. Concentrations of QACs in sewage-impacted estuarine sediments (up to 74 ?g/g) were higher than concentrations of other organic contaminants measured in the same or nearby samples, suggesting further study is needed. PMID:19739657

  18. Ammoniums quaternaires et pathologies professionnelles

    Microsoft Academic Search

    M.-L. Hemery

    2008-01-01

    Quaternary ammonium compounds are widely used in many occupations (conservation, cleaning and disinfection) and all the workers in these occupations are exposed to the potentially irritant or allergenic effects to these products. The clinical manifestations are usually dermatological but respiratory symptoms such as rhinitis or respiratory symptoms are more and more often seen by occupational disease. The nature of the

  19. Highly sensitive assay for tiotropium, a quaternary ammonium, in human plasma by high-performance liquid chromatography/tandem mass spectrometry.

    PubMed

    Wang, Jiang; Jiang, Yao; Wang, Yingwu; Li, Hao; Fawcett, J Paul; Gu, Jingkai

    2007-01-01

    Tiotropium bromide, a long-acting inhaled bronchodilator analogous to ipratropium bromide, is currently undergoing development for the treatment of chronic obstructive pulmonary disease. To evaluate its systemic absorption in humans, we have developed a rapid and sensitive method for its determination in human plasma based on high-performance liquid chromatography with tandem mass spectrometric detection (HPLC/MS/MS). Reversed-phase chromatography of tiotropium and the internal standard clenbuterol was carried out using acetonitrile/10 mM ammonium acetate (1% formic acid) 40:60 as mobile phase in a run time of 3.0 min. The sample preparation involved deproteination with acetonitrile, extraction into dichloromethane and back-extraction into hydrochloric acid. The assay was linear over the concentration range 0.500-50.0 pg/mL with intra- and inter-day precision (as relative standard deviation) both

  20. Methyl chloride via oxhydrochlorination of methane

    SciTech Connect

    Jarvis, R.F. Jr.

    1997-12-31

    Dow Corning is developing a route from methane to methyl chloride via oxyhydrochlorination (OHC) chemistry with joint support from the Gas Research Institute and the Department of Energy Federal Energy Technology Center. Dow Corning is the world`s largest producer of methyl chloride and uses it as an intermediate in the production of silicone materials. Other uses include production of higher hydrocarbons, methyl cellulose, quaternary ammonium salts and herbicides. The objective of this project is to demonstrate and develop a route to methyl chloride with reduced variable cost by using methane instead of methanol raw materials. Methyl chloride is currently produced from methanol, but U.S. demand is typically higher than available domestic supply, resulting in fluctuating prices. OHC technology utilizes domestic natural gas as a feedstock, which allows a lower-cost source of methyl chloride which is independent of methanol. In addition to other uses of methyl chloride, OHC could be a key step in a gas-to-liquid fuels process. These uses could divert significant methanol demand to methane. A stable and selective catalyst has been developed in the laboratory and evaluated in a purpose-built demonstration unit. Materials of construction issues have been resolved and the unit has been run under a range of conditions to evaluate catalyst performance and stability. Many technological advances have been made, especially in the areas of catalyst development, online FTIR analysis of the product stream, and recovery of methyl chloride product via an absorber/stripper system. Significant technological hurdles still remain including heat transfer, catalysts scaleup, orthogonality in modeling, and scaleable absorption data. Economics of the oxyhydrochlorination process have been evaluated an found to be unfavorable due to high capital and utility costs. Future efforts will focus on improved methane conversion at high methyl chloride selectivity.

  1. A comparative study on absorption and selectivity of organic vapors by using ionic liquids based on imidazolium, quaternary ammonium, and guanidinium cations.

    PubMed

    Kulkarni, Prashant S; Branco, Luís C; Crespo, João G; Afonso, Carlos A M

    2007-01-01

    A novel study on organic solute absorption from the vapor phase is reported. The organic solutes chosen for the absorption studies include 1,4-benzodioxane, biphenyl, xanthene, and menthol. A series of imidazolium, ammonium, and guanidinium-based ionic liquids (ILs) containing several types of anions were used as absorbents. Absorption of water vapor was also studied along with the organic solutes. Absorption studies of each organic solute were performed by using a specially devised glass apparatus at 50 degrees C. It was observed that the rate of absorption increases with time and is faster in the case of 1,4-benzodioxane (24 h). The absorption process for each organic solute with different classes of ionic liquids was studied and the results were compared with each other. Absorption values of more than 25,000 ppm were observed in some ionic liquids. Distribution ratios of organic solutes in an ionic liquid and in the vapor phase were measured and the selectivity was evaluated by using the distribution ratio values. A remarkable selectivity was observed for some ionic liquids towards a specific organic solute. Importantly, it was observed that the selectivity remained constant, even though a mixture of solute was used for the absorption study. Desorption of organic vapors from ionic liquids was successfully carried out by applying a vacuum. Further, it was observed that the same ionic liquid can be repeatedly reused several times for absorption. These studies reveal that, in future, a task-specific ionic liquid can be prepared and used for specific solute capture from the vapor phase. PMID:17566129

  2. 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.

  3. Effects of Benzalkonium Chloride on Planktonic Growth and Biofilm Formation by Animal Bacterial Pathogens

    PubMed Central

    Ebrahimi, Azizollah; Hemati, Majid; Shabanpour, Ziba; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Lotfalian, Sharareh; Khubani, Shahin

    2015-01-01

    Background: Resistance toward quaternary ammonium compounds (QACs) is widespread among a diverse range of microorganisms and is facilitated by several mechanisms such as biofilm formation. Objectives: In this study, the effects of benzalkonium chloride on planktonic growth and biofilm formation by some field isolates of animal bacterial pathogens were investigated. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus aureus and Streptococcus agalactiae (10 isolates of each) were examined for effects of benzalkonium chloride on biofilm formation and planktonic growth using microtiter plates. For all the examined strains in the presence of benzalkonium chloride, biofilm development and planktonic growth were affected at the same concentrations of disinfectant. Results: The means of strains growth increase after the minimal inhibitory concentration (MIC) were significant in all the bacteria (except for E. coli in 1/32 and S. agalactiae in of 1/8 MIC). Biofilm formation increased with decrease of antiseptics concentration; a significant increase was found in all the samples. The most turbidity related to S. aureus and the least to Salmonella. Conclusions: Bacterial resistance against quaternary ammonium compounds is increasing which can increase the bacterial biofilm formation.

  4. Synthesis and application of a quaternary phosphonium polymer coagulant to avoid N-nitrosamine formation.

    PubMed

    Zeng, Teng; Pignatello, Joseph J; Li, Russell Jingxian; Mitch, William A

    2014-11-18

    Quaternary ammonium cationic polymers, such as poly(diallyldimethylammonium chloride) (polyDADMAC) are widely used for coagulating and removing negatively charged particles and dissolved organic matter (DOM) from drinking water. Their use, however, has been linked to the formation of carcinogenic N-nitrosamines as byproducts during chloramine-based drinking water disinfection. In this study, a novel quaternary phosphonium cationic polymer, poly(diallyldiethylphosphonium chloride) (polyDADEPC), was synthesized such that the quaternary nitrogen atom of polyDADMAC was substituted with a phosphorus atom. Formation potential tests revealed that even under strong nitrosation conditions, polyDADEPC and related lower-order P-based compounds formed oxygenated and not nitrosated products. Bench-scale jar tests using three different source waters further demonstrated that polyDADEPC achieved coagulation performance comparable to commercial polyDADMACs for particle and DOM removals within the typical dose range used for drinking water treatment. This work highlights the potential use of a phosphonium coagulant polymer, polyDADEPC, as a viable alternative to polyDADMAC to avoid nitrosated byproduct formation during chloramination. PMID:25322258

  5. Ammonium fluoride as a novel chemical modifier for the elimination of magnesium chloride interference on the determination of lead by graphite furnace atomic absorption spectrometry.

    PubMed

    Husáková, Lenka; Srámková, Jitka; Cernohorský, Tomás; Barinová, Martina

    2007-06-15

    Ammonium fluoride was found to be very efficient modifier for the elimination of MgCl(2) interference on Pb determination. Ammonium fluoride probably converts strongly interfering volatile MgCl(2) to less volatile MgF(2) matrix that makes possible the release of Pb analyte at lower temperature, before the matrix starts to vaporize. It was observed likewise that NH(4)F removes the interferences mentioned, i.e. caused by MgCl(2) presence, much more effectively as compared with some modifiers, before now recommended for this purpose. The application of this modifier to the determination of Pb in 2% (m/v) MgCl(2) has ensured the characteristic mass and LOD value in the original sample of 12pg and 60ngg(-1), respectively (10mul aliquots of sample). Applying the modifier to standards and samples enables the use of matrix-free standard solutions for attaining accurate analysis as verified by recovery studies. PMID:19071775

  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. Quaternary Studies

    NSDL National Science Digital Library

    First, the Irish Quaternary Association (IQUA) website publicizes its aim "to promote Quaternary studies in Ireland through its publications, and the organization of field meetings and conferences" (1). Visitors can learn about the importance of quaternary studies as well as find out the latest news and upcoming meetings. At the second website, the University of Wisconsin-Madison describes the current and recent studies dealing with "basic and applied problems in glacial geology, surficial geology, palynology, sedimentology, geologic mapping, hydrogeology, soils, and environmental geology "(2). The website offers abstracts of publications of members of the Department of Geology and Geophysics and the Wisconsin Geological and Natural History Survey along with descriptions of the lab, a shaded relief map of the Wisconsin area, and amusing glacial songs. Next, the Godwin Institute of Quaternary Research (GIQR) presents the University of Cambridge's history in quaternary research and the seven current research groups and four recent research projects (3 ). The website furnishes news from the research groups, a gallery of historical images of the East Anglia excursion, and summaries of the Institute's reference collections. Fourth, the International Union for Quaternary Research (INQUA) discusses quaternary scientists' investigations "to interpret the changing world of the glacial ages and their impact on our planet's surface environments" (4). Researchers can find out about INQUA-funded projects, meetings, and scientific commissions. Next, the Quaternary Research Association explains that it "exists to promote understanding of the Quaternary Period by publishing field guides, technical guides, and an international journal as well as holding field meetings and speaker meetings" (5). Students and researchers can discover employment, research, grant, meetings, and educational opportunities. Sixth, the University of Wales presents its investigations in the Remote Sensing Laboratory, Palaeoecology Laboratory, and the Luminescence Laboratory (6 ). Users can find concise descriptions of individual researchers' successes, abstracts of published papers, and links to conference information. The seventh website illustrates the Alaska Quaternary Center's commitment "to the promotion of interdisciplinary research and the enhancement of interdisciplinary instruction in Quaternary sciences" (7). Users can view images of the field work and learn how to obtain quaternary data from the Geographic Information Network of Alaska (GINA). Lastly, Rutgers University promotes its Graduate Certificate in Quaternary Studies where students take part in geology, geography, meteorology, and other disciplines interested in the last couple of million years of Earth's history (8). Students and educators can find information on the researchers involved with the program and the necessary course work.

  8. Quaternary investigation

    SciTech Connect

    Stieve, A.

    1991-05-15

    The primary purpose of the Quaternary investigation is to provide information on the location and age of Quaternary deposits for use in evaluating the presence or absence of neotectonic deformation or paleoliquefaction features within the Savannah River Site (SRS) region. The investigation will provide a basis for evaluating the potential for capable faults and associated deformation in the SRS vicinity. Particular attention will be paid to the Pen Branch fault.

  9. Liquid chromatography of hydrocarbonaeous quaternary amines on cyclodextrin bonded silica

    USGS Publications Warehouse

    Abidi, S.L.

    1986-01-01

    Mixtures of n-alkylbenzyldimethylammonium chloride (ABDAC) were resolved into homologous components by high-performance liquid chromatography (HPLC) with a cyclodextrin-bonded silica stationary phase. With a few exceptions, results from this study are similar to those obtained from traditional reversed-phase HPLC. It was found that the presence of electrolytes in aqueous mobile phases is not a critical factor in determining the success of HPLC separation. Under normal HPLC conditions, a mobile phase consisting of either methanol–water (50:50) or acetonitrile–water (30:70) was employed for obtaining adequate resolution of the quaternary ammonium mixtures. Although the percent organic modifier–water profiles were similar to those in previous studies with these compounds, resolution (R) and selectivity (?) parameters were found to be quite susceptible to changes in the mobile phase solvent composition. The retention behavior of the cationic analytes in the homologous series is consistent with the hydrophobic-interaction concept proposed for the retention mechanism via dominant inclusion complex formation. Several electrolytes were chosen for a study of the counter ion effect on the chromatographic characteristics of ABDAC components. Among the electrolytes examined, the perchlorate ion was found most likely to act as an ion-pairing counter ion for ammonium cations in the HPLC system studied. A correlation study established linear relationships between the chain length of ABDAC and the logarithmic capacity factor (k2). The analytical utility of the HPLC method was demonstrated by the analysis of various unknown mixtures.

  10. [Properties of benzethonium chloride in micellar solutions and the effect of added sodium chloride].

    PubMed

    Kopecký, F; Kopecká, B; Kaclík, P

    2006-07-01

    Aqueous solutions of the antimicrobially effective quaternary ammonium salt benzethonium chloride (hyamine 1622) were studied using UV spectrophotometry and partially conductometry. The spectra of micellar solutions of benzethonium chloride revealed a concentration-dependent bathochromic and hyperchromic shift of a weak UV absorption band in the region 250-300 nm. This served to elaborate the spectrophotometric determination of the critical micellar concentration (CMC) of benzethonium chloride and the concentration of free benzethonium cations in micellar solutions without an addition of NaCl and with a constant addition of NaCl 0.003, 0.1 and 0.15 mol/l. Premicellar associations were not observed and in NaCl-free solutions CMC 0.0028 mol/l was spectrophotometrically determined. An addition of NaCl resulted in an increased hyperchromic effect and strengthening of micellization, manifested by a more than ten-times decrease in the CMC as well as the concentration of free benzethonium cations in micellar solutions. The courses of the determined concentrations of free benzethonium cations in the solutions both without and with the presence of NaCl were quite similar; their maximal values were always just a little higher than the corresponding CMC and with a further growth of the total concentration of benzethonium chloride there was, on the other hand, a marked decrease in the concentration of its free cations in micellar solution. Possible effects of a decreased concentration of free benzethonium cations due to an added electrolyte on antimicrobial activity and formation of ionic pairs are discussed. PMID:16921736

  11. Comparative toxicity of ammonium and nitrate compounds to Pacific treefrog and African clawed frog tadpoles

    Microsoft Academic Search

    G. S. Schuytema; A. V. Nebeker

    1999-01-01

    The effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific treefrog (Pseudacris regilla [Baird and Girard]) and African clawed frog (Xenopus laevis [Daudin]) tadpoles were determined in static-renewal tests. The 10-d ammonium nitrate and ammonium sulfate LC50s for P. regilla were 55.2 and 89.7 mg\\/L NHâ-N, respectively. The 10-d LC50s for X.

  12. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...prescribed conditions: (a) The food additive is produced by one of the following...hexa-decyl-ammonium chloride. (b) The food additive described in paragraph...

  13. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...prescribed conditions: (a) The food additive is produced by one of the following...hexa-decyl-ammonium chloride. (b) The food additive described in paragraph...

  14. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...prescribed conditions: (a) The food additive is produced by one of the following...hexa-decyl-ammonium chloride. (b) The food additive described in paragraph...

  15. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...prescribed conditions: (a) The food additive is produced by one of the following...hexa-decyl-ammonium chloride. (b) The food additive described in paragraph...

  16. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...prescribed conditions: (a) The food additive is produced by one of the following...hexa-decyl-ammonium chloride. (b) The food additive described in paragraph...

  17. The size of hydroxyl groups in solution and the changes in size associated with the ionization of phenolic, carboxylic and amino groups in phenolic quaternary ammonium salts, nicotine and some amino acids: possible implications for drug-water and drug-receptor interactions.

    PubMed Central

    Barlow, R. B.

    1980-01-01

    Size in solution can be expressed either as the apparent molal volume at infinite dilution (phi 0v) amd the concentration parameter (j) or as the partial molal volume of the solute at infinite dilution (V0(2)) and the concentration parameter for the solute or solvent (qs or qw). Although calculated differently, these are derived from the same results and are equivalent. From measurement with phenolic quaternary ammonium salts, including compounds with high nicotine-like activity, the apparent size of the hydroxyl group in water is small and variable. Phenolic groups are slightly larger than alcoholic groups, which should be better hydrogen donors. By measuring the volume change associated with ionisation it is possible to measure the size of charged groups such as phenate and carboxylate; these are much smaller than phenolic and carboxyl. Ammonium groups, however, are only slightly smaller than the corresponding amines. The zwitterion forms of amino acids are associated with a minimum in volume but the volume changes increase with chain length from glycine to gamma-aminobutyric acid. Groups separated by less than this distance interact in their effects on water. Decreases in volume or unexpectedly small increments in apparent molal volume represent decreases in entropy which must be taken into account in drug-water-receptor interactions. Although they may be offset by enthalpy changes, they should favour binding because there is more scope for an increase in entropy. This might explain the association of the small apparent size in water of the hydroxyl group in many compounds with its effects of their affinity for receptors. PMID:7470734

  18. Supporting Information for: Ammonium Bicarbonate Transport in Anion Exchange Membranes

    E-print Network

    S1 Supporting Information for: Ammonium Bicarbonate Transport in Anion Exchange Membranes was measured by first equilibrating the polymer film in the desired solution [e.g., DI water, 0.5 mol/L sodium chloride (NaCl), or 0.5 mol/L ammonium bicarbonate (AmB)]. Films were allowed to equilibrate

  19. The Alaska Quaternary Center

    NSDL National Science Digital Library

    This website illustrates the Alaska Quaternary Center's (at the University of Alaska, Fairbanks) commitment "to the promotion of interdisciplinary research and the enhancement of interdisciplinary instruction in Quaternary sciences." Users can view images of the field work and learn how to obtain quaternary data from the AQC Quaternary Research Geodatabase.

  20. Irish Quaternary Association (IQUA)

    NSDL National Science Digital Library

    The Irish Quaternary Association (IQUA) website publicizes its aim "to promote Quaternary studies in Ireland through its publications, and the organization of field meetings and conferences." Visitors can learn about the importance of quaternary studies, find out the latest news and upcoming meetings, and find links to Quaternary studies journals.

  1. Salmonella enterica Strains with Reduced Susceptibility to Quarternary Ammonium Compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Salmonella spp. are responsible for 76 million illnesses per year in the U.S. Quaternary ammonium compounds (QAC) are commonly used antimicrobial agents. Reduced susceptibility to these compounds by a broad spectrum of organisms is a concern. Methods: Salmonella enterica strains with r...

  2. Comparative Effects of Ammonium and Nitrate Compounds on Pacific Treefrog and African Clawed Frog Embryos

    Microsoft Academic Search

    G. S. Schuytema; A. V. Nebeker

    1999-01-01

    .   The effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific\\u000a treefrog (Pseudacris regilla) and African clawed frog (Xenopus laevis) embryos were determined in static-renewal tests. The 10-day LC50s for the three ammonium compounds for P. regilla ranged from 25.0–32.4 mg\\/L NH4 -N. The 10-day sodium nitrate LC50 for P. regilla was

  3. NEUTRON SCATTERING AND CATION ROTATIONAL MOTION IN TETRAMETHYLAMMONIUM MANGANESE CHLORIDE

    E-print Network

    Paris-Sud XI, Université de

    473 NEUTRON SCATTERING AND CATION ROTATIONAL MOTION IN TETRAMETHYLAMMONIUM MANGANESE CHLORIDE B sample of tetramethylammonium manganese chloride has been measured for 0-500 cm-1energy transfers, both ammonium manganese chloride, (CH3)4MnCl3 exhibits the properties of a one-dimen- sional anti-ferro magnet

  4. Vinyl Chloride

    Cancer.gov

    Vinyl chloride is a colorless gas that burns easily. It does not occur naturally and must be produced industrially for its commercial uses. Vinyl chloride is used primarily to make polyvinyl chloride (PVC); PVC is used to make a variety of plastic products, including pipes, wire and cable coatings, and packaging materials. Vinyl chloride is also produced as a combustion product in tobacco smoke.

  5. Quaternary and Geomorphology.

    ERIC Educational Resources Information Center

    Andrews, J. T.; Graf, W. L.

    1983-01-01

    Highlights conferences and meetings of organizations involved with quaternary geology and geomorphology, including International Union of Quaternary Research Conference held in Moscow. The impetus of a revision of "The Quaternary of the United States" resulted from this conference. Includes activities/aims of "Friends of the Pleistocene"…

  6. Ammonium metabolism in humans.

    PubMed

    Adeva, Maria M; Souto, Gema; Blanco, Natalia; Donapetry, Cristóbal

    2012-11-01

    Free ammonium ions are produced and consumed during cell metabolism. Glutamine synthetase utilizes free ammonium ions to produce glutamine in the cytosol whereas glutaminase and glutamate dehydrogenase generate free ammonium ions in the mitochondria from glutamine and glutamate, respectively. Ammonia and bicarbonate are condensed in the liver mitochondria to yield carbamoylphosphate initiating the urea cycle, the major mechanism of ammonium removal in humans. Healthy kidney produces ammonium which may be released into the systemic circulation or excreted into the urine depending predominantly on acid-base status, so that metabolic acidosis increases urinary ammonium excretion while metabolic alkalosis induces the opposite effect. Brain and skeletal muscle neither remove nor produce ammonium in normal conditions, but they are able to seize ammonium during hyperammonemia, releasing glutamine. Ammonia in gas phase has been detected in exhaled breath and skin, denoting that these organs may participate in nitrogen elimination. Ammonium homeostasis is profoundly altered in liver failure resulting in hyperammonemia due to the deficient ammonium clearance by the diseased liver and to the development of portal collateral circulation that diverts portal blood with high ammonium content to the systemic blood stream. Although blood ammonium concentration is usually elevated in liver disease, a substantial role of ammonium causing hepatic encephalopathy has not been demonstrated in human clinical studies. Hyperammonemia is also produced in urea cycle disorders and other situations leading to either defective ammonium removal or overproduction of ammonium that overcomes liver clearance capacity. Most diseases resulting in hyperammonemia and cerebral edema are preceded by hyperventilation and respiratory alkalosis of unclear origin that may be caused by the intracellular acidosis occurring in these conditions. PMID:22921946

  7. Additive Screen HTTM -HR2-138 Scoring Sheet 1. (A1) 0.1 M Barium Chloride

    E-print Network

    Hill, Chris

    Chloride 3. (A3) 0.1 M Calcium Chloride 4. (A4) 0.1 M Cobaltous Chloride 5. (A5) 0.1 M Cupric Chloride 6 Praseodymium (III) Acetate 15. (B3) 1.0 M Ammonium Sulfate 16. (B4) 1.0 M Potassium Chloride 17. (B5) 1.0 M

  8. Synthesis and properties of chiral ammonium-based ionic liquids.

    PubMed

    Pernak, Juliusz; Feder-Kubis, Joanna

    2005-07-18

    New chiral ammonium-based ionic liquids containing the (1R,2S,5R)-(-)-menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air- and moisture-stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single-crystal X-ray structure of butyldimethyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride has been determined. The chiral, room-temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities. PMID:15883984

  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. Bacterial resistance to Quaternary Ammonium Compounds (QAC) disinfectants.

    PubMed

    Bragg, Robert; Jansen, Arina; Coetzee, Marisa; van der Westhuizen, Wouter; Boucher, Charlotte

    2014-01-01

    Control of bacterial diseases has, for many years, been dependent on the use of antibiotics. Due to the high levels of efficacy of antibiotics in the past other disease control options have, to a large extent, been neglected. Mankind is now facing an increasing problem with antibiotic resistance. In an effort to retain some antibiotics for human use, there are moves afoot to limit or even ban the use of antibiotics in animal production. The use of antibiotics as growth promoters have been banned in the European Union and the USA. The potential ban on the use of antibiotics to treat diseases in production animals creates a dilemma for man-suffer significant problem with bacterial infection or suffer from a severe shortage of food! There are other options for the control of bacterial diseases. These include vaccine development, bacteriophage therapy, and improved biosecurity. Vaccine development against bacterial pathogens, particularly opportunistic pathogens, is often very challenging, as in many cases the molecular basis of the virulence is not always clearly understood. This is particularly true for Escherichia coli. Biosecurity (disinfection) has been a highly neglected area in disease control. With the ever-increasing problems with antibiotic resistance-the focus should return to improvements in biosecurity. As with antibiotics, bacteria also have mechanisms for resistance to disinfectants. To ensure that we do not replace one set of problems (increasing antibiotic resistance) with another (increasing resistance to disinfectants) we need to fully understand the modes of action of disinfectants and how the bacteria develop resistance to these disinfectants. Molecular studies have been undertaken to relate the presence of QAC resistance genes in bacteria to their levels of sensitivity to different generations of QAC-based products. The mode of action of QAC on bacteria has been studied using NanoSAM technology, where it was revealed that the QAC causes disruption of the bacterial cell wall and leaking of the cytoplasm out of the cells. Our main focus is on the control of bacterial and viral diseases in the poultry industry in a post-antibiotic era, but the principles remain similar for disease control in any veterinary field as well as in human medicine. PMID:24595606

  11. Quaternary ammonium borohydride adsorption in mesoporous silicate MCM-48

    SciTech Connect

    Wolverton, Michael J [Los Alamos National Laboratory; Daemen, Luke L [Los Alamos National Laboratory; Hartl, Monika A [Los Alamos National Laboratory

    2010-01-01

    Inorganic borohydrides have a high gravimetric hydrogen density but release H2 only under energetically unfavorable conditions. Surface chemistry may help in lowering thermodynamic barriers, but inclusion of inorganic borohydrides in porous silica materials has proved hitherto difficult or impossible. We show that borohydrides with a large organic cation are readily adsorbed inside mesoporous silicates, particularly after surface treatment. Thermal analysis reveals that the decomposition thermodynamics of tetraalkylammonium borohydrides are substantially affected by inclusion in MCM-48. Inelastic neutron scattering (INS) data show that the compounds adsorb on the silica surface. Evidence of pore loading is supplemented by DSC/TGA, XRD, FTIR, and BET isotherm measurements. Mass spectrometry shows significant hydrogen release at lower temperature from adsorbed borohydrides in comparison with the bulk borohydrides. INS data measured for partially decomposed samples indicates that the decomposition of the cation and anion is likely simultaneous. Additionally, these data confirm the formation of Si-H bonds on the silica surface upon decomposition of adsorbed tetramethylammonium borohydride.

  12. AMBIENT AMMONIA AND AMMONIUM AEROSOL ACROSS A REGION OF VARIABLE AMMONIA EMISSION DENSITY

    EPA Science Inventory

    The paper presents one year of ambient ammonia (NH3), ammonium (NH4+), hydrochloric acid (HCI), chloride (CI¯), nitric acid (HNO3), nitrate (NO3¯), nitrous acid (HONO), sulfur dioxide (SO2), and sulfate (SO4...

  13. Adverse Effect of Ammonium Salts on the Antibacterial Activity of Paraformaldehyde Solutions

    PubMed Central

    Myers, G. E.; McCready, R. G. L.

    1963-01-01

    The antibacterial activity of aqueous solutions of paraformaldehyde in concentrations from 0.1 to 0.4% (w/v) is bacteriostatic rather than bactericidal in the presence or absence of ammonium chloride. The presence of ammonium chloride significantly lengthened the time of exposure to paraformaldehyde necessary for inhibition of growth of the test organism (Staphylococcus aureus FDA 209) when unbuffered solutions were used. Elevation of the pH of the reacting mixture of paraformaldehyde and ammonium chloride by partial buffering lengthened the time of exposure necessary for inhibition of growth of the test organism. Decrease of antibacterial activity was concomitant with the disappearance of paraformaldehyde from the reacting mixture. The reaction of paraformaldehyde with ammonium chloride was rapid at room temperature (25 C) and at pH levels near neutrality. The fate of the reacting paraformaldehyde, including the possibility of the formation of hexamethylenetetramine or methylenimine, is discussed with particular reference to loss of antibacterial activity. PMID:13936950

  14. DEMONSTRATION OF TWO STABLE POTENTIAL STATES IN THE SQUID GIANT AXON UNDER TETRAETHYLAMMONIUM CHLORIDE

    Microsoft Academic Search

    ICHIJI TASAKI; SUSUMU HAGIWARA

    1957-01-01

    During the course of experiments designed to investigate the effects of various chemicals injected into squid giant axons (2), it was found that quater- nary ammonium ions are capable of prolonging the duration of the action potential without affecting the properties of the resting membrane appreciably. A similar effect of quaternary ammonium ions upon the action potential of other excitable

  15. Quaternary Research Association

    NSDL National Science Digital Library

    The Quaternary Research Association explains that it "exists to promote understanding of the Quaternary Period by publishing field guides, technical guides, and an international journal as well as holding field meetings and speaker meetings." Students and researchers can discover employment, research, grant, meetings, and educational opportunities.

  16. 40 CFR Table 2 to Subpart B of... - MON Source Categories

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Production. Polyvinyl Alcohol Production. Polyvinyl Butyral Production. Ammonium Sulfate Production-Caprolactam By-Product Plants. Quaternary Ammonium Compounds Production. Benzyltrimethylammonium Chloride Production....

  17. 40 CFR Table 2 to Subpart B of... - MON Source Categories

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Production. Polyvinyl Alcohol Production. Polyvinyl Butyral Production. Ammonium Sulfate Production-Caprolactam By-Product Plants. Quaternary Ammonium Compounds Production. Benzyltrimethylammonium Chloride Production....

  18. 40 CFR Table 2 to Subpart B of... - MON Source Categories

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Production. Polyvinyl Alcohol Production. Polyvinyl Butyral Production. Ammonium Sulfate Production-Caprolactam By-Product Plants. Quaternary Ammonium Compounds Production. Benzyltrimethylammonium Chloride Production....

  19. 40 CFR Table 2 to Subpart B of... - MON Source Categories

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Production. Polyvinyl Alcohol Production. Polyvinyl Butyral Production. Ammonium Sulfate Production-Caprolactam By-Product Plants. Quaternary Ammonium Compounds Production. Benzyltrimethylammonium Chloride Production....

  20. 40 CFR Table 2 to Subpart B of... - MON Source Categories

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Production. Polyvinyl Alcohol Production. Polyvinyl Butyral Production. Ammonium Sulfate Production-Caprolactam By-Product Plants. Quaternary Ammonium Compounds Production. Benzyltrimethylammonium Chloride Production....

  1. Impaired Urinary Ammonium Excretion in Patients With Isolated Proximal Renal Tubular Acidosis

    Microsoft Academic Search

    Luis G. Brenes; Marta I. Sanchez

    During previous studies in patients with isolated prox- imal renal tubular acidosis (pRTA), the rates of urinary ammonium excretion were considered inappro- priately low for their state of chronic metabolic aci- dosis. These observations were made while the pa- tients were on a normal diet as well as when they were undergoing a short ammonium chloride test. Because these findings

  2. Overcoming ammonium toxicity.

    PubMed

    Bittsánszky, András; Pilinszky, Katalin; Gyulai, Gábor; Komives, Tamas

    2015-02-01

    Ammonia (ammonium ion under physiological conditions) is one of the key nitrogen sources in cellular amino acid biosynthesis. It is continuously produced in living organisms by a number of biochemical processes, but its accumulation in cells leads to tissue damage. Current knowledge suggests that a few enzymes and transporters are responsible for maintaining the delicate balance of ammonium fluxes in plant tissues. In this study we analyze the data in the scientific literature and the publicly available information on the dozens of biochemical reactions in which endogenous ammonium is produced or consumed, the enzymes that catalyze them, and the enzyme and transporter mutants listed in plant metabolic and genetic databases (Plant Metabolic Network, TAIR, and Genevestigator). Our compiled data show a surprisingly high number of little-studied reactions that might influence cellular ammonium concentrations. The role of ammonium in apoptosis, its relation to oxidative stress, and alterations in ammonium metabolism induced by environmental stress need to be explored in order to develop methods to manage ammonium toxicity. PMID:25576003

  3. Mechanism of HERG potassium channel inhibition by tetra-n-octylammonium bromide and benzethonium chloride

    SciTech Connect

    Long, Yan; Lin, Zuoxian [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Xia, Menghang; Zheng, Wei [National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892 (United States); Li, Zhiyuan, E-mail: li_zhiyuan@gibh.ac.cn [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

    2013-03-01

    Tetra-n-octylammonium bromide and benzethonium chloride are synthetic quaternary ammonium salts that are widely used in hospitals and industries for the disinfection and surface treatment and as the preservative agent. Recently, the activities of HERG channel inhibition by these compounds have been found to have potential risks to induce the long QT syndrome and cardiac arrhythmia, although the mechanism of action is still elusive. This study was conducted to investigate the mechanism of HERG channel inhibition by these compounds by using whole-cell patch clamp experiments in a CHO cell line stably expressing HERG channels. Tetra-n-octylammonium bromide and benzethonium chloride exhibited concentration-dependent inhibitions of HERG channel currents with IC{sub 50} values of 4 nM and 17 nM, respectively, which were also voltage-dependent and use-dependent. Both compounds shifted the channel activation I–V curves in a hyperpolarized direction for 10–15 mV and accelerated channel activation and inactivation processes by 2-fold. In addition, tetra-n-octylammonium bromide shifted the inactivation I–V curve in a hyperpolarized direction for 24.4 mV and slowed the rate of channel deactivation by 2-fold, whereas benzethonium chloride did not. The results indicate that tetra-n-octylammonium bromide and benzethonium chloride are open-channel blockers that inhibit HERG channels in the voltage-dependent, use-dependent and state-dependent manners. - Highlights: ? Tetra-n-octylammonium and benzethonium are potent HERG channel inhibitors. ? Channel activation and inactivation processes are accelerated by the two compounds. ? Both compounds are the open-channel blockers to HERG channels. ? HERG channel inhibition by both compounds is use-, voltage- and state dependent. ? The in vivo risk of QT prolongation needs to be studied for the two compounds.

  4. Chloride Test

    MedlinePLUS

    ... problem with your body's electrolyte balance or acid-base balance and to monitor treatment When to Get ... fluid in the body and maintain the acid-base balance . Chloride is present in all body fluids ...

  5. Molecular Structure of Ammonium ion

    NSDL National Science Digital Library

    2002-09-10

    The first widespread production of ammonium compounds occurred during the 1890s when ammonium sulfate was produced as a by-product from coke oven gas. Ammonium ion is produced as a product of the reaction of water and ammonia. Often, ammonium salts are isomorphous. They have a similar solubility to potassium and rubidium salts, whose ions are similar in size to ammonium. The ion is most stable in the presence of a large compound with a single negative charge.

  6. 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

  7. Chloride channelopathies.

    PubMed

    Planells-Cases, Rosa; Jentsch, Thomas J

    2009-03-01

    Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms. Impaired chloride transport can cause diseases as diverse as cystic fibrosis, myotonia, epilepsy, hyperekplexia, lysosomal storage disease, deafness, renal salt loss, kidney stones and osteopetrosis. These disorders are caused by mutations in genes belonging to non-related gene families, i.e. CLC chloride channels and transporters, ABC transporters, and GABA- and glycine receptors. Diseases due to mutations in TMEM16E and bestrophin 1 might be due to a loss of Ca++-activated Cl- channels, although this remains to be shown. PMID:19708126

  8. Purification of Ammonium Alum

    Microsoft Academic Search

    G. Dillon; A. Armington

    1962-01-01

    IGH-purity ammonium alum is of interest in the magnetics field as a starting compound in the preparation of aluminum oxide for use as a matrix material in synthetic crystals. The authors investi­ gated several purification procedures in an attempt to improve the purity of presently available alums; zone refining of hydrated alum, recrystallization, and sol­ vent extraction. Zone-refining experiments were

  9. Ammonium inhibition of nitrogenase activity in Herbaspirillum seropedicae

    SciTech Connect

    Fu, H.; Burris, R.H. (Univ. of Wisconsin, Madison (USA))

    1989-06-01

    The effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated N{sub 2}-fixing bacterium Herbaspirillum seropedicae was investigated in comparison with Azospirillum spp. and Rhodospirillum rubrum. H. seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kPa for dinitrogen fixation but higher when it is supplied with fixed nitrogen. No nitrogenase activity was detected when the dissolved O{sub 2} level corresponded to 4.0 kPa. Ammonium, a product of the nitrogenase reaction, reversible inhibited nitrogenase activity when added to derepressed cell cultures. However, the inhibition of nitrogenase activity was only partial even with concentrations of ammonium chloride as high as 20 mM. Amides such as glutamine and asparagine partially inhibited nitrogenase activity, but glutamate did not. Nitrogenase in crude extracts prepared from ammonium-inhibited cells showed activity as high as in extracts from N{sub 2}-fixing cells. The pattern of the dinitrogenase and the dinitrogenase reductase revealed by the immunoblotting technique did not change upon ammonium chloride treatment of cells in vivo. No homologous sequences were detected with the draT-draG probe from Azospirillum lipoferum. There is no clear evidence that ADP-ribosylation of the dinitrogenase reductase is involved in the ammonium inhibition of H. seropedicae. The uncoupler carbonyl cyanide m-chlorophenylhydrazone decreased the intracellular ATP concentration and inhibited the nitrogenase activity of whole cells. The ATP pool was significantly disturbed when cultures were treated with ammonium in vivo.

  10. Synthesis and performance of ester quaternary biodegradable softeners

    Microsoft Academic Search

    R. Lagerman; S. Clancy; D. Tanner; N. Johnston; B. Callian; F. Friedli

    1994-01-01

    Reaction of hydroxyethylpiperazine with two moles of fatty acid, followed by quaternization with methyl chloride, methyl bromide\\u000a or dimethyl sulfate, resulted in new quaternaries useful as biodegradable fabric softeners. Additional softeners were synthesized\\u000a from hard tallow propane diamine by reaction with butyrolactone, followed by ethoxylation, esterification with one mole of\\u000a fatty acid and quaternization.

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

  14. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

  15. 4, 29492971, 2004 Ammonium sulfate

    E-print Network

    Paris-Sud XI, Université de

    ACPD 4, 2949­2971, 2004 Ammonium sulfate ­ malonic acid aerosols C. F. Braban and J. P. D. Abbatt and Physics Discussions A study of the phase transition behavior of mixed ammonium sulfate ­ malonic acid Ammonium sulfate ­ malonic acid aerosols C. F. Braban and J. P. D. Abbatt Title Page Abstract Introduction

  16. Quaternary Faunal Environments

    NSDL National Science Digital Library

    Christopher Hill

    Students collect information the environments associated with a list of presently living mammals. Students use FAUNMAP to explore the spatial patterns associated with these living mammals during the late Quaternary. They compare these distributions for living mammals to the distribution patterns for a set of extinct mammals. Students answer a set of questions that provide a basis for a summary report.

  17. Experimental study of directional solidification of aqueous ammonium chloride solution

    NASA Technical Reports Server (NTRS)

    Chen, C. F.; Chen, Falin

    1991-01-01

    Directional solidification experiments have been carried out using the analog casting system of NH4Cl-H2O solution by cooling it from below with a constant-temperature surface ranging from -31.5 C to +11.9 C. The NH4Cl concentration was 26 percent in all solutions, with a liquidus temperature of 15 C. It was found that finger convection occurred in the fluid region just above the mushy layer in all experiments. Plume convection with associated chimneys in the mush occurred in experiments with bottom temperatures as high as +11.0 C. However, when the bottom temperature was raised to +11.9 C, no plume convection was observed, although finger convection continued as usual. A method has been devised to determine the porosity of the mush by computed tomography. Using the mean value of the porosity across the mush layer and the permeability calculated by the Kozeny-Carman relationship, the critical solute Rayleigh number across the mush layer for onset of plume convection was estimated to be between 200 and 250.

  18. The shape of ammonium chloride dendrite tips at small supersaturation

    NASA Astrophysics Data System (ADS)

    Dougherty, Andrew; Lahiri, Mayank

    2003-03-01

    We report detailed measurements of the tip shapes of three-dimensional NH_4Cl dendrites grown from aqueous solution at small supersaturation.[1] We compare three different models for determining the tip position and shape: parabolic, parabolic with a fourth-order correction, and power law[2]. We also consider an intensity centroid method[3] useful for locating tip positions even when the tip is too small to image accurately. None of these methods is ideal, but the fourth-order fit appears to provide the most robust description of both the tip shape and position for the crystals grown in this work. Since all models considered include data a finite distance back from the tip, the question of whether incipient sidebranches contaminate the computed tip position and shape will be considered when looking for possible tip oscillations. 1. More details and references are available at http://www.lafayette.edu/%7Edoughera/talks/aps2003/index.html 2. U. Bisang and J. H. Bilgram, Phys. Rev. E 54, 5309 (1996). 3. J. C. LaCombe et al., Phys. Rev. E 65, 031604 (2002).

  19. Sidebranching in the Dendritic Crystal Growth of Ammonium Chloride

    NASA Astrophysics Data System (ADS)

    Dougherty, Andrew; Stinner, Franklin

    2010-03-01

    We report new measurements of the dendritic crystal growth of NH4Cl from supersaturated aqueous solution. We report the first measurement of the capillary length d0 to be approximately 2 x10-4 ?m. For growth at small dimensionless supersaturations ? on the order of 0.005, we have estimated the stability constant &*circ; to be approximately 0.008. The origin of the sidebranches in dendritic growth is not fully understood, but one model is that they result from the selective amplification of microscopic noise. We will compare measurements of the sidebranch envelope with predictions of the noise-induced sidebranching model of Gonz'alez-Cinca, Ram'irez-Piscina, Casademunt, and Hern'andez-Machado [Phys Rev. E, 63, 051602 (2001)]. A second model is that sidebranches result from small oscillations of the tip. We have observed no such oscillations, but very small ones can not be ruled out. Given the finite experimental resolution, no measurement of the tip region can be completely free of contamination from early sidebranches. We will discuss this and other experimental challenges that need to be overcome before we can understand the origin of sidebranches.

  20. Sidebranching in the Dendritic Crystal Growth of Ammonium Chloride

    NASA Astrophysics Data System (ADS)

    Dougherty, Andrew

    2012-02-01

    We report measurements of the dendritic crystal growth of NH4Cl from supersaturated aqueous solution at small supersaturations. Sidebranch growth in this regime is challenging to model well, and the origin of the sidebranches is not fully understood. The early detection of sidebranches requires measurements of small deviations from the smooth steady state shape, but that shape is not well known at the intermediate distances relevant for sidebranch measurements. One model is that sidebranches result from the selective amplification of microscopic noise. We compare measurements of the sidebranch envelope with predictions of the noise-induced sidebranching model of Gonz'alez-Cinca, Ram'irez-Piscina, Casademunt, and Hern'andez-Machado [Phys Rev. E, 63, 051602 (2001)]. We find that the measured amplitude is somewhat larger than predicted, and the shape of the sidebranch envelope is also different. A second model is that sidebranches result from small oscillations of the tip. We have observed no such oscillations, but very small ones can not be ruled out. No measurement of the tip region can be completely free of contamination from early sidebranches, so it can be challenging to distinguish between an oscillating tip and a smooth tip with sidebranches starting nearby.

  1. Isotopic and Hydrogeochemical Studies on Abnormally High Ammonium of Natural Origin in A Coastal Aquifer-aquitard System

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Jiao, J. J.; Cherry, J.

    2010-12-01

    Excessive nitrogen concentration in water bodies is regarded as an environmental contamination because of its possible harm to human bodies and significant ecological effects. Previous studies commonly concerned on elevated nitrogen in water of anthropogenic origins, such as agricultural, domestic, sewage and industrial discharges, because people realize that it is necessary to manage negative influences of human being to the natural environment. Understanding contamination sources of nitrogen is crucial for both waste discharge management and pollutants cleanup. This study was aimed to 1) understand the spatial distribution of abnormally high ammonium groundwater in the Quaternary basalt aquifer in the Pearl River Delta (PRD), China; 2) to distinguish sources of recharge to the basalt aquifer; and 3) to identify the origin of the ammonium in the aquitard and aquifer system. Total 40 boreholes were drilled, and approximately 1000 deposit samples from the aquitard and over 200 groundwater samples from the Quaternary basalt aquifer were collected. A cluster of 7 piezometers was installed in Minzhong Town to study the hydraulic relationships between the aquitard and the basalt aquifer. The results demonstrated that the greater groundwater ammonium concentrations were preserved in the aquifer buried deeper. The ammonium concentration up to 390 mg/L was observed in the basalt sand and gravel Pleistocene aquifer of 20-50m deep, and this is the greatest concentration ever reported for natural groundwater globally. The Quaternary aquitard, which contained abundant sedimentary organic matter and was mainly composed of silt and clay, provided a strict anaerobic environment for sedimentary organic matter mineralization and ammonium preservation. Ammonium concentrations in the aquifer were predominantly controlled by the aquitard ammonium content. This naturally occurring abnormally high ammonium in the Quaternary sediments is areally extensive (over 1600 km2). Great groundwater salinity originated from a marine source redounded to the release of adsorbed ammonium to groundwater via ion exchange processes. This naturally originated high ammonium groundwater may find its way to the river channels and estuary. The flow paths are likely shortened by sand dredging activities Literature shows that no particular studies have been developed for ammonium research in delta aquitards and aquifers. The geological settings of fine texture of delta sediments containing abundant sedimentary organic matter are not unique to the PRD, and this “geological” ammonium may not be an uncommon source of nitrogen and may present as a large and hitherto unappreciated source of nitrogen for surface water bodies.

  2. Altered pulmonary defense system in lung injury induced by didecyldimethylammonium chloride in mice.

    PubMed

    Ohnuma, Aya; Yoshida, Toshinori; Horiuchi, Haruka; Fukumori, Junko; Tomita, Mariko; Kojima, Sayuri; Takahashi, Naofumi; Fukuyama, Tomoki; Hayashi, Koichi; Yamaguchi, Satoru; Ohtsuka, Ryoichi; Kashimoto, Yukiko; Kuwahara, Maki; Takeda, Makio; Kosaka, Tadashi; Nakashima, Nobuaki; Harada, Takanori

    2011-07-01

    Didecyldimethylammonium chloride (DDAC), a representative dialkyl-quaternary ammonium compound (QAC), could contaminate working atmospheres when used in disinfectant operation and adversely affect human health. Furthermore, the development of bacteria resistant to DDAC might become public health concern. We postulated that DDAC instillation in the lungs alters pulmonary antioxidant and antimicrobial responses and increases susceptibility to systemic administration of a bacterial component lipopolysaccharide (LPS). Mice were intratracheally instilled with DDAC and sacrificed 1, 3, or 7 days after treatment. Pulmonary cytotoxicity in recovered bronchoalveolar lavage was evident on Days 1 and 7, and inflammatory cell influx and interleukin-6 expression peaked on Day 7, in association with altered antioxidant and antimicrobial responses, as demonstrated by measuring heme oxygenase-1, glutathione peroxidase 2, lactoferrin, and mouse ?-defensin-2 and -3 mRNA in the lung samples. The impaired defense system tended to enhance the inflammatory reaction caused by a systemic administration of LPS; the effect was in association with increased expression of toll-like receptor-4 mRNA. The results suggest that DDAC alters pulmonary defense system, which may contribute to susceptibility to an exogenous infectious agent. PMID:21689009

  3. Ammonium diphosphitoindate(III).

    PubMed

    Hamchaoui, Farida; Rebbah, Houria; Le Fur, Eric

    2013-04-01

    The crystal structure of the title compound, NH4[In(HPO3)2], is built up from In(III) cations (site symmetry 3m.) adopting an octa-hedral environment and two different phosphite anions (each with site symmetry 3m.) exhibiting a triangular-pyramidal geometry. Each InO6 octa-hedron shares its six apices with hydrogen phosphite groups. Reciprocally, each HPO3 group shares all its O atoms with three different metal cations, leading to [In(HPO3)2](-) layers which propagate in the ab plane. The ammonium cation likewise has site symmetry 3m.. In the structure, the cations are located between the [In(HPO3)2](-) layers of the host framework. The sheets are held together by hydrogen bonds formed between the NH4 (+) cations and the O atoms of the framework. PMID:23633983

  4. 76 FR 47238 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ...Second Review] Ammonium Nitrate From Russia Determination On the basis of the record...antidumping duty order on ammonium nitrate from Russia would be likely to lead to continuation...2011), entitled Ammonium Nitrate from Russia: Investigation No....

  5. 76 FR 11273 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ...Second Review)] Ammonium Nitrate From Russia AGENCY: United States International Trade...investigation on ammonium nitrate from Russia...investigation on ammonium nitrate from Russia would be likely to lead to...

  6. Density, local composition and diffusivity of aqueous choline chloride solutions: a molecular dynamics study

    Microsoft Academic Search

    Timothy I. Morrow; Edward J. Maginn

    2004-01-01

    We report the results of a molecular dynamics study of aqueous solutions of n-hydroxyethyl-trimethyl-ammonium chloride (choline chloride). An all-atom forcefield is developed for choline chloride, while the SPC\\/E model is used for water. The calculations predict densities that agree to within 1% of the values subsequently reported by the National Institute of Standards and Technology as part of the Industrial

  7. 75 FR 56489 - Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ...maximum elemental sulfur, 0.150% maximum chloride as Cl, or particulated elemental metals...than 90 percent ammonium nitrate mixed with calcium carbonate and/or dolomite and/or mineral calcium sulphate, and not more than 0.4...

  8. Quaternary GIS Laboratory

    NSDL National Science Digital Library

    This is the home page of the Quaternary Geographic Information System (GIS) Laboratory at the Institute of Arctic and Alpine Research (INSTAAR) at the University of Colorado. The laboratory supports quantitative spatial analysis of glacier, climate, coastal, and other environmental relationships at high latitudes. Users can access a collection of climate animations for the State of Alaska which show seasonal variation in monthly temperature and precipitation. There is also a set of high-resolution imagery and terrain models for Barrow, Alaska, an animation of the land bridge between Asia and North America, an atlas of paleoglaciation for the state, and links to a variety of other projects involving climatology, paleoclimatology, and glacial geomorphology in the Sate of Alaska.

  9. Global modeling of nitrate and ammonium aerosols using EQSAM3

    NASA Astrophysics Data System (ADS)

    Xu, L.; Penner, J. E.

    2009-12-01

    Atmospheric aerosols, particles suspending in air, are important as they affect human health, air quality, and visibility as well as climate. Sulfate, nitrate, ammonium, chloride and sodium are among the most important inorganic aerosol species in the atmosphere. These compounds are hygroscopic and absorb water under almost all ambient environmental conditions. The uptake of water alters the aerosol size, and causes water to become the constituent with the largest atmospheric aerosol mass, especially when the aerosols grow into fog, haze or clouds. Furthermore, several global model studies have demonstrated that rapid increases in nitrogen emissions could produce enough nitrate in aerosols to offset the expected decline in sulfate forcing by 2100 for the extreme IPCC A2 scenario (Bauer et al., 2007). Although nitrate and ammonium were identified as significant anthropogenic sources of aerosols by a number of modeling studies, most global aerosol models still exclude ammonium-nitrate when the direct aerosol forcing is studied. In this study, the computationally efficient equilibrium model, EQSAM3, is incorporated into the UMICH-IMPACT-nitrate model using the hybrid dynamical solution method (Feng and Penner, 2007). The partitioning of nitrate and ammonium along with the corresponding water uptake is evaluated by comparing the model to the EQUISOLVE II method used in Feng and Penner (2007). The model is also evaluated by comparison with the AERONET data base and satellite-based aerosol optical depths.

  10. Thermal decomposition of ammonium uranates

    Microsoft Academic Search

    Taichi Sato; Shigeaki Shiota

    1985-01-01

    The thermal decomposition of ammonium uranates precipitated from uranyl nitrate solution on the addition of aqueous ammonium hydroxide and hexamine under various conditions has been studied by means of thermogravimetry, differential thermal analysis, infrared spectroscopy and X-ray diffraction. Although all precipitates show the composition corresponding to UO3 · NH3 · H2O, the precipitates with hexamine give X-ray diffraction patterns designed

  11. Prolonged exposure of mixed aerobic cultures to low temperature and benzalkonium chloride affect the rate and extent of nitrification.

    PubMed

    Yang, Jeongwoo; Tezel, Ulas; Li, Kexun; Pavlostathis, Spyros G

    2015-03-01

    The combined effect of benzalkonium chloride (BAC) and prolonged exposure to low temperature on nitrification was investigated. Ammonia oxidation at 22-24°C by an enriched nitrifying culture was inhibited at increasing BAC concentrations and ceased at 15 mg BAC/L. The non-competitive inhibition coefficient was 1.5±0.9 mg BAC/L. Nitrification tests were conducted without and with BAC at 5mg/L using an aerobic, mixed heterotrophic/nitrifying culture maintained at a temperature range of 24-10°C. Maintaining this culture at 10°C for over one month in the absence of BAC, resulted in slower nitrification kinetics compared to those measured when the culture was first exposed to 10°C. BAC was degraded by the heterotrophic population, but its degradation rate decreased significantly as the culture temperature decreased to 10°C. These results confirm the negative impact of quaternary ammonium compounds on the nitrification process, which is further exacerbated by prolonged, low temperature conditions. PMID:25544497

  12. Long-term exposure to benzalkonium chloride disinfectants results in change of microbial community structure and increased antimicrobial resistance.

    PubMed

    Tandukar, Madan; Oh, Seungdae; Tezel, Ulas; Konstantinidis, Konstantinos T; Pavlostathis, Spyros G

    2013-09-01

    The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health. PMID:23924280

  13. 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. PMID:22366608

  14. Natrix -Scoring Sheet 1. 0.01 M Mg Chloride, 0.05 M MES pH 5.6, 2.0 M Lithium Sulfate

    E-print Network

    Hill, Chris

    Acetate, 0.05 M MES pH 5.6, 2.5 M Ammonium Sulfate 3. 0.1 M Mg Acetate, 0.05 M MES pH 5.6, 20% MPD 4. 0 Chloride, 0.05 M MES pH 5.6, 5% PEG 8000 6. 0.1 M Ammonium Sulfate, 0.01 M Mg Chloride, 0.05 M MES pH 5 Sulfate 13. 0.015 M Mg Acetate, 0.05 M Na Cacodylate pH 6.0, 1.7 M Ammonium Sulfate 14. 0.1 M K Chloride

  15. Chromate ion adsorption by agricultural by-products modified with dimethyloldihydroxyethylene urea and choline chloride

    Microsoft Academic Search

    Lynda H. Wartelle; Wayne E. Marshall

    2005-01-01

    The use of cellulose-containing agricultural by-products modified with the cross-linking reagent dimethyloldihydroxyethylene urea (DMDHEU) and the quaternary amine, choline chloride, as anion exchange resins, has not been reported. The objective of the present study was to convert the readily available by-products, soybean hulls, sugarcane bagasse and corn stover to functional anion exchange resins using DMDHEU and choline chloride. Optimization of

  16. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...

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

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  17. Saline-water contamination in Quaternary deposits and the Poplar River, East Poplar Oil Field, northeastern Montana

    USGS Publications Warehouse

    Thamke, J.N.; Craigg, S.D.

    1997-01-01

    The extent of saline-water contamination in Quaternary deposits in and near the East Poplar oil field may be as much as 12.4 square miles and appears to be present throughout the entire saturated zone. The saline-water contamination affects 9-60 billion gallons of ground water. Saline- contaminated water moves westward through Quaternary glacial deposits and merges with southward-flowing water in Quaternary alluvium in the Poplar River valley. Saline ground water discharges into the Poplar River, and increases the dissolved-solids and chloride concentrations of the river. The probable source of saline-water contamination in the Quaternary deposits is brine that is a byproduct of the production of crude oil in the East Poplar oil field study area.

  18. TOXICOLOGICAL REVIEW OF METHYL CHLORIDE [AND IRIS SUMMARY] (EXTERNAL PEER REVIEW DRAFT)

    EPA Science Inventory

    Methyl chloride (CAS No. 74-87-3) is a gaseous chlorohydrocarbon under ambient conditions. It is principally used in the manufacture of silicones, agrichemicals, methyl cellulose and quaternary amines. Numerous case reports involving overexposure over the last 60 years indicate t...

  19. Crystal Screen HT -Scoring Sheet A1. 30% MPD, 0.1 M Na Acetate pH 4.6, 0.02 M Calcium Chloride

    E-print Network

    Hill, Chris

    . 0.4 M K, Na Tartrate A3. 0.4 M Ammonium Phosphate A4. 2.0 M Ammonium Sulfate, 0.1 M Tris HCl pH 8.2 M Calcium Chloride B3. 30% PEG 8000, 0.1 M Na Cacodylate pH 6.5, 0.2 M Ammonium Sulfate B4. 1.5 M HCl pH 8.5, 0.2 M Ammonium Acetate B8. 25% PEG 4000, 0.1 M Na Acetate pH 4.6, 0.2 M Ammonium Sulfate B

  20. Crystal Screen Lite -Scoring Sheet 1. 15% MPD, 0.1 M Na Acetate pH 4.6, 0.02 M Calcium Chloride

    E-print Network

    Hill, Chris

    . 0.2 M K, Na Tartrate 3. 0.2 M Ammonium Phosphate 4. 1.0 M Ammonium Sulfate, 0.1 M Tris HCl pH 8.5 5 Calcium Chloride 15. 15% PEG 8000, 0.1 M Na Cacodylate pH 6.5, 0.2 M Ammonium Sulfate 16. 0.75 M Lithium.5, 0.2 M Ammonium Acetate 20. 12.5% PEG 4000, 0.1 M Na Acetate pH 4.6, 0.2 M Ammonium Sulfate 21. 15

  1. Influence of Heterogeneous Ammonium Availability on Bacterial

    E-print Network

    Lovley, Derek

    and the Expression of Nitrogen Fixation and Ammonium Transporter Genes during in Situ Bioremediation of Uranium bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by 2 orders microbial processes during bioremediation. Introduction

  2. Quaternary Glaciers of New Zealand

    Microsoft Academic Search

    D. J. A. Barrell

    2011-01-01

    Located in the southwestern Pacific Ocean, New Zealand's record of Quaternary glaciations, preserved in landforms and near-surface deposits, begins at the margins of modern glaciers and extends outwards geographically and backwards in time, to the last glaciation and beyond. The record becomes increasingly fragmentary into the Middle and Early Pleistocene.

  3. Quaternary uplift of southern Italy

    Microsoft Academic Search

    Rob Westaway

    1993-01-01

    Dramatic coastline changes demonstrate rapid Quaternary uplift of Calabria in southern Italy. Because most of the west (Tyrrhenian Sea) coast is normal fault bounded, previous work has asserted that its uplift is local footwall uplift related to extension. However, the east (Ionian Sea) coast is also uplifting but is not normal fault bounded. This reanalysis, based on original field work

  4. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a...

  5. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a...

  6. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a...

  7. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a...

  8. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a...

  9. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...is manufactured by the reaction of 99.5 percent ammonia...of 37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...for reporting adverse reactions or to request a...

  10. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...is manufactured by the reaction of 99.5 percent ammonia...of 37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...for reporting adverse reactions or to request a...

  11. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...is manufactured by the reaction of 99.5 percent ammonia...of 37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...for reporting adverse reactions or to request a...

  12. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...is manufactured by the reaction of 99.5 percent ammonia...of 37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...37 percent ammonium salt of formic acid and 62...for reporting adverse reactions or to request a...

  13. Deliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate/Succinic Acid Microparticles

    E-print Network

    not take up a significant amount of water. Additionally, the deliquescence relative humidity is foundDeliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate of ammonium nitrate/water and mixed ammonium nitrate/succinic acid/water microparticles. The water activity

  14. Quaternary polymethacrylate-magnesium aluminum silicate films: molecular interactions, mechanical properties and tackiness.

    PubMed

    Rongthong, Thitiphorn; Sungthongjeen, Srisagul; Siepmann, Juergen; Pongjanyakul, Thaned

    2013-12-15

    The aim of this study was to investigate the impact of the addition of magnesium aluminum silicate (MAS), a natural clay, on the properties of polymeric films based on quaternary polymethacrylates (QPMs). Two commercially available aqueous QPM dispersions were studied: Eudragit(®) RS 30D and Eudragit(®) RL 30D (the dry copolymers containing 5 and 10% quaternary ammonium groups, respectively). The composite QPM-MAS films were prepared by casting. Importantly, QPM interacted with MAS and formed small flocculates prior to film formation. Continuous films were obtained up to MAS contents of 19% (referred to the QPM dry mass). ATR-FTIR and PXRD revealed that the positively charged quaternary ammonium groups of QPM interacted with negatively charged SiO(-) groups of MAS, creating nanocomposite materials. This interaction led to improved thermal stability of the composite films. The puncture strength and elongation at break of dry systems decreased with increasing MAS content. In contrast, the puncture strength of the wet QPM-MAS films (upon exposure to acidic or neutral media) increased with increasing MAS content. Furthermore, incorporation of MAS into QPM films significantly decreased the latter's tackiness in the dry and wet state. These findings suggest that nanocomposite formation between QPM and MAS in the systems can enhance the strength of wet films and decrease their tackiness. Thus, MAS offers an interesting potential as novel anti-tacking agent for QPM coatings. PMID:24144950

  15. Comparison of the ion exchange uptake of ammonium ion onto New Zealand clinoptilolite and mordenite.

    PubMed

    Weatherley, L R; Miladinovic, N D

    2004-12-01

    In this study the uptake performances of the naturally occurring zeolite, clinoptilolite, and of New Zealand mordenite are compared. The uptake of fully ionised ammonium ion from aqueous solutions in the concentration range 0-200 mg/l on to these two materials was compared. The influence of other cations present in water upon the ammonia uptake was also determined. The cations studied were potassium, calcium and magnesium. In all cases the anionic counterion present was chloride. The results showed that the mordenite exhibited higher overall uptake concentrations at equilibrium compared with clinoptilolite at solution concentrations greater than 80 mg/l. Beyond this value, the difference in solid-phase equilibrium concentrations on the mordenite became greater at higher solution-phase ammonium ion concentrations. The effect of the other cations upon uptake of ammonium ion was relatively small. In all cases, the ammonium ion showed the highest uptake on to both the mordenite and the clinoptilolite. In the case of clinoptilolite this was rather an unexpected result since the majority of other work shows clinoptilolite exhibiting a higher affinity for potassium ion compared with ammonium ion. This may be explained by the fact that the clinoptilolite came from volcanic deposits in New Zealand. This is the first such study on this material. At solution-phase equilibrium concentrations of greater than 80 mg/l, the mordenite showed smaller reductions in ammonium ion uptake in the presence of the other cations when compared with clinoptilolite. PMID:15556205

  16. Determination of benzethonium chloride in anthrax vaccine adsorbed by HPLC

    Microsoft Academic Search

    Hsiaoling Wang; Alfred V. Del Grosso; Joan C. May

    2006-01-01

    A novel and sensitive HPLC method for the determination of benzethonium chloride (BZC) in anthrax vaccine was developed. Adjuvant Alhydrogel was removed by syringe filter after a simple sample pretreatment—acidification prior to injection. Chromatography was performed by isocratic reverse phase separation with methanol\\/262mM ammonium acetate (80\\/20, v\\/v) on an endcapped C18 column with diode array detector (DAD). The method showed

  17. (2-Chloroethyl)-trimethylammonium Chloride inhibits Gametogenesis in Locusts

    Microsoft Academic Search

    D. B. Carlisle; Peggy E. Ellis; L. J. McVeigh

    1968-01-01

    THE plant growth retardant (2-chloroethyl)-trimethyl-ammonium chloride (CCC, `Cycocel') has been shown to reduce the longevity and fecundity of aphids. Van Emden1 grew brussels sprouts in soil to which CCC had been added; Tahori, Halevy and Zeidler2 used cut oleander leaves with their petioles standing in a solution, while Bhalla and Robinson3 added 0.5 to 2.0 per cent of CCC to

  18. 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...

  19. Antimicrobial and inhibitory enzyme activity of N-(benzyl) and quaternary N-(benzyl) chitosan derivatives on plant pathogens.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I; Taktak, Nehad E M

    2014-10-13

    Chemical modification of a biopolymer chitosan by introducing quaternary ammonium moieties into the polymer backbone enhances its antimicrobial activity. In the present study, a series of quaternary N-(benzyl) chitosan derivatives were synthesized and characterized by (1)H-NMR, FT-IR and UV spectroscopic techniques. The antimicrobial activity against crop-threatening bacteria Agrobacterium tumefaciens and Erwinia carotovora and fungi Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum and Phytophthora infestans were evaluated. The results proved that the grafting of benzyl moiety or quaternization of the derivatives onto chitosan molecule was successful in inhibiting the microbial growth. Moreover, increase water-solubility of the compounds by quaternization significantly increased the activity against bacteria and fungi. Exocellular enzymes including polygalacturonase (PGase), pectin-lyase (PLase), polyphenol oxidase (PPOase) and cellulase were also affected at 1000 mg/L. These compounds especially quaternary-based chitosan derivatives that have good inhibitory effect should be potentially used as antimicrobial agents in crop protection. PMID:25037402

  20. 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 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

  1. 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 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

  2. 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 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

  3. 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 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

  4. 3,16-Bisquaternary ammonium steroid derivatives as neuromuscular blocking agents: Synthesis and biological evaluation.

    PubMed

    Hu, Hao; Rao, Zhigang; Feng, Min; Wu, Zhe; Xu, Jianrong; Chen, Hongzhuan; Liu, Peng; Xiao, Yuling; Hong, Xuechuan; Hu, Xianming; Ke, Xianbing

    2015-04-01

    Neuromuscular blocking agents (NMBAs) are widely used in surgery to achieve skeleton muscles relaxation under light anesthesia status. In this work, we synthesized a series of 3,16-bisquaternary ammonium steroidal NMBAs. Among them, three compounds exhibited higher in vitro activities than the commenced drug rocuronium. In addition, structure-activity relationship was unveiled. We found that the intact acetylcholine-like moiety in D-ring was not necessary for maintaining activity but both the acetyl group and the quaternary nitrogen were very essential. PMID:25637675

  5. Polyurethane-based polymer surface modifiers with alkyl ammonium copolyoxetane soft segments: Reaction engineering, surface morphology and antimicrobial behavior

    NASA Astrophysics Data System (ADS)

    Brunson, Kennard Marcellus, Jr.

    Concentrating quaternary (positive) charge at polymer surfaces is important for applications including layer-by-layer polyelectrolyte deposition and antimicrobial coatings. Prior techniques to introduce quaternary charge to the surface involve grafting of quaternary ammonium moieties to a substrate or using polyurethanes with modified hard segments however there are impracticalities involved with these techniques. In the case of the materials discussed, the quaternary charge is introduced via polyurethane based polymer surface modifiers (PSMs) with quaternized soft segments. The particular advantage to this method is that it utilizes the intrinsic phase separation between the hard and soft segments of polyurethanes. This phase separation results in the surface concentration of the soft segments. Another advantage is that unlike grafting, where modification has to take place after device fabrication, these PSMs can be incorporated with the matrix material during device fabrication. The soft segments of these quaternized polyurethanes are produced via ring opening co-polymerization of oxetane monomers which possess either a trifluoroethoxy (3FOx) side chains or a quaternary ammonium side chain (C12). These soft segments are subsequently reacted with 4,4'-(methylene bis (p-cyclohexyl isocyanate)), HMDI and butanediol (BD) to form the PSM. It was initially intended to increase the concentration of quaternary ammonium charge by increasing PSM soft segment molecular weight. Unexpectedly, produced blends with surface microscale phase separation. This observation prompted further investigation of the effect of PSM soft segment molecular weight on phase separation in PSM-base polyurethane blends and the subsequent effects of this phase separation on the biocidal activity. Analysis of the surface morphology via tapping mode atomic force microscopy (TM-AFM) and scanning electron microscopy (SEM) revealed varying complexities in surface morphology as a function of the PSM soft segment molecular weight and initial annealing temperature. Many of these features include what are described as nanodots (100-300 nm), micropits (0.5-2 mum) and micropeaks (1-10 mum). It was also observed that surface morphology continued to coarsen with time and that the larger features were typically observed in blends containing PSMs with low molecular weight soft segments. This appearance of surface morphological feature correlates with decreased biocidal activity of the PSM blends, that is, the PSM blends exhibit little to no activity upon development of phase separated features. A model has been developed for phase separation and concomitant reduction of surface quaternary charge. This model points the way to future work that will stabilize surface charge and provide durability of surface modification.

  6. Quaternary ecology: A paleoecological perspective

    SciTech Connect

    Delcourt, H.R.; Delcourt, P.A.

    1991-01-01

    This book considers issues and problems in ecology which may be illuminated, if not solved, by considering paleoecology. The five central chapters include a discussion of application of Quaternary ecology to future global climate change, including global warming. Other areas presented include: population dispersal, invasions, expansions, and migrations; plant successions; ecotones; factors in community structure; ecosystem patterns and processes. Published case studies are numerous. The role played by continuing climatic change in vegetation change is acknowledged but not stressed.

  7. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron-reducing conditions

    NASA Astrophysics Data System (ADS)

    Huang, S.; Jaffé, P. R.

    2015-02-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron was measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454 pyrosequencing, and real-time quantitative PCR analysis. We be Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  8. Equilibrium Studies of Sodium-Ammonium, Potassium-Ammonium, and Calcium-Ammonium Exchanges on Clinoptilolite Zeolite

    Microsoft Academic Search

    M. A. Jama; H. Yuecel

    1989-01-01

    Forward and reverse ion-exchange isotherms for the binary sodium-ammonium, potassium-ammonium, and calcium-ammonium systems on clinoptilolite have been measured in aqueous solutions at a total concentration of 0.1 equiv\\/dm and at 298 K. Prior to exchange experiments it was attempted to prepare homoionic forms of the zeolite by exhaustive treatments with appropriate salt solutions of cations. With no binary exchanges, full

  9. ANAEROBIC AMMONIUM OXIDATION IN THE MARINE ENVIRONMENT

    Microsoft Academic Search

    Marcel M. M. Kuypers; Gaute Lavik; Bo Thamdrup

    Oceanographers noticed already many years ago that far less ammonium accumulated in anoxic fjords and basins, than would be\\u000a expected from the stoichiometry of heterotrophic denitrification. It was suggested that this ‘missing’ ammonium was oxidized\\u000a with nitrate to freeN2. Since then several otherworkers have argued based on chemical profiles that ammonium is oxidized anaerobically in oxygen\\u000a deficient marine sediments and

  10. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate...Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY...

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...5 compatibility group D. (f) No mixture containing ammonium nitrate and any ingredient which would accelerate the decomposition of ammonium nitrate under conditions incident to transportation may be transported by vessel. [Amdt. 176-30,...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...5 compatibility group D. (f) No mixture containing ammonium nitrate and any ingredient which would accelerate the decomposition of ammonium nitrate under conditions incident to transportation may be transported by vessel. [Amdt. 176-30,...

  13. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...5 compatibility group D. (f) No mixture containing ammonium nitrate and any ingredient which would accelerate the decomposition of ammonium nitrate under conditions incident to transportation may be transported by vessel. [Amdt. 176-30,...

  14. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...5 compatibility group D. (f) No mixture containing ammonium nitrate and any ingredient which would accelerate the decomposition of ammonium nitrate under conditions incident to transportation may be transported by vessel. [Amdt. 176-30,...

  15. Ammonium assmilation in spruce ectomycorrhizas

    SciTech Connect

    Chalot, M.; Brun, A.; Botton, B. (Univ. of nancy, Vandoeuvre-les-Nancy (France)); Stewart, G. (University College, London (England))

    1990-05-01

    Assimilation of labelled NH{sub 4}{sup +} into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH{sub 4}{sup +} feeding, Gln, Glu and Ala became the most abundant amino acids. Gln was also the most highly labelled amino acid during the experiment, followed by Glu and Ala. This result indicates that Gln synthesis is an important ammonium utilization reaction in spruce mycorrhizas. Addition of MSX to NH{sub 4}{sup +} fed mycorrhizas caused an inhibition of Gln accumulation with a corresponding increase in Glu, Ala and Asn levels. The supply of MSX induced a sharp diminution of {sup 15}N enrichment in both amino and amido groups of glutamine. In contrast, the {sup 15}N incorporation into Glu and derivatives (Ala and Asp) remained very high. This study demonstrates that the fungal glutamate dehydrogenase is quite operative in spruce ectomycorrhizas since it is able to sustain ammonium assimilation when glutamine synthetase is inhibited.

  16. An Electronic Tongue Designed to Detect Ammonium Nitrate in Aqueous Solutions

    PubMed Central

    Campos, Inmaculada; Pascual, Lluis; Soto, Juan; Gil-Sánchez, Luis; Martínez-Máñez, Ramón

    2013-01-01

    An electronic tongue has been developed to monitor the presence of ammonium nitrate in water. It is based on pulse voltammetry and consists of an array of eight working electrodes (Au; Pt; Rh; Ir; Cu; Co; Ag and Ni) encapsulated in a stainless steel cylinder. In a first step the electrochemical response of the different electrodes was studied in the presence of ammonium nitrate in water in order to further design the wave form used in the voltammetric tongue. The response of the electronic tongue was then tested in the presence of a set of 15 common inorganic salts; i.e.; NH4NO3; MgSO4; NH4Cl; NaCl; Na2CO3; (NH4)2SO4; MgCl2; Na3PO4; K2SO4; K2CO3; CaCl2; NaH2PO4; KCl; NaNO3; K2HPO4. A PCA plot showed a fairly good discrimination between ammonium nitrate and the remaining salts studied. In addition Fuzzy Art map analyses determined that the best classification was obtained using the Pt; Co; Cu and Ni electrodes. Moreover; PLS regression allowed the creation of a model to correlate the voltammetric response of the electrodes with concentrations of ammonium nitrate in the presence of potential interferents such as ammonium chloride and sodium nitrate. PMID:24145916

  17. Comparative effects of ammonium and nitrate compounds on Pacific treefrog and African clawed frog embryos.

    PubMed

    Schuytema, G S; Nebeker, A V

    1999-02-01

    The effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific treefrog (Pseudacris regilla) and African clawed frog (Xenopus laevis) embryos were determined in static-renewal tests. The 10-day LC50s for the three ammonium compounds for P. regilla ranged from 25.0-32. 4 mg/L NH4 -N. The 10-day sodium nitrate LC50 for P. regilla was 578. 0 mg/L NO3-N. LC50s for X. laevis exposed for 4 or 5 days to the three ammonium compounds ranged from 27.5-60.2 mg/L NH4-N. The sodium nitrate LC50 for X. laevis ranged from 438.4-871.6 mg/L NO3-N. The lowest LOAEL based on length or weight was 6.1 mg/L NH4-N for the two species. The lowest LOAELs for NO3-N were 111.1 mg/L for P. regilla and 56.7 mg/L for X. laevis. Calculated unionized NH3 comprised 0.5-1.8% of measured NH4-N concentrations. Potential harm to amphibian populations could occur if NH4-N and NO3-N in agricultural runoff or drainage impacts sensitive life stages for a sufficiently long period. PMID:9888966

  18. Nitric oxide supplementation alleviates ammonium toxicity in the submerged macrophyte Hydrilla verticillata (L.f.) Royle.

    PubMed

    Wang, Chao; Zhang, Song He; Li, Wei; Wang, Pei Fang; Li, Li

    2011-01-01

    The likely protective effects of nitric oxide (NO) against ammonium toxicity were investigated in the submerged macrophyte Hydrilla verticillata. The plants were subjected to ammonium stress (3mM ammonium chloride) in the presence of sodium nitroprusside (SNP, 10 ?M), an NO donor. Treatment with SNP significantly increased the NO content and partially reversed the ammonium-induced negative effects, including membrane damage and the decrease in levels of chlorophyll, malondialdehyde, glutathione and ascorbic acid. Further, SNP application increased the catalytic activities of ascorbate peroxidase, superoxide dismutase, guaiacol peroxidase, catalase and glutathione S-transferase, but decreased that of NADH-oxidase. Histochemical staining showed that SNP application caused a significant decrease in the levels of superoxides and hydrogen peroxide. In contrast, application of other breakdown products of SNP (10 ?M sodium ferrocyanide, 10 ?M sodium nitrite and 10 ?M sodium nitrate) failed to show any protective effect. The results suggest that the increased intracellular NO, resulting from SNP application, improved the antioxidant capacity of H. verticillata plants in coping with ammonium-induced oxidative stress. PMID:20655590

  19. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, ...

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

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT OF CENTER WITH TOP OF SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  20. Comparative toxicity of ammonium and nitrate compounds to Pacific treefrog and African clawed frog tadpoles

    SciTech Connect

    Schuytema, G.S.; Nebeker, A.V.

    1999-10-01

    The effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific treefrog (Pseudacris regilla [Baird and Girard]) and African clawed frog (Xenopus laevis [Daudin]) tadpoles were determined in static-renewal tests. The 10-d ammonium nitrate and ammonium sulfate LC50s for P. regilla were 55.2 and 89.7 mg/L NH{sub 4}-N, respectively. The 10-d LC50s for X. laevis for the three ammonium compounds ranged from 45 to 64 mg/L NH{sub 4}-N. The 10-d sodium nitrate LC50s were 266.2 mg/L NO{sub 3}-N for P. regilla and 1,236.2 mg/L NO{sub 3}-N for X. laevis. The lowest observed adverse effect level (LOAEL) of ammonium compound based on reduced length or weight was 24.6 mg/L NH{sub 4}-N for P. regilla and 99.5 mg/L NH{sub 4}-N for X. laevis. The lowest sodium nitrate LOAELs based on reduced length or weight were {lt}30.1 mg/L NO{sub 3}-N for P. regilla and 126.3 mg/L NO{sub 3}-N for X. laevis. Calculated un-ionized NH{sub 3} comprised 0.3 to 1.0% of measured NH{sub 4}-N concentrations. Potential harm to amphibians could occur if sensitive life stages were impacted by NH{sub 4}-N and NO{sub 3}-N in agricultural runoff or drainage for a sufficiently long period.

  1. Stereoselective Synthesis of Quaternary Proline Analogues

    PubMed Central

    Calaza, M. Isabel

    2009-01-01

    This review describes available methods for the diastereoselective and asymmetric synthesis of quaternary prolines. The focus is on the preparation of ?-functionalized prolines with the pyrrolidine moiety not embedded in a polycyclic frame. The diverse synthetic approaches are classified according to the bond which is formed to complete the quaternary skeleton. PMID:19655047

  2. 75 FR 40729 - Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ...product (4% ai.)) mg/kg/day (333 ug/ guinea pigs MRID cm2)b 41105801 UFA = 3x...Formulated-based dermal endpoint = (20 mg/kg guinea pig x 0.43 kg guinea pig x 1,000 ug/mg)/25.8cm2 area of guinea...

  3. Quaternary ammonium functionalized clay film electrodes modified with polyphenol oxidase for the sensitive detection of catechol

    Microsoft Academic Search

    Justin Kemmegne Mbouguen; Emmanuel Ngameni; Alain Walcarius

    2007-01-01

    Naturally occurring Cameroonian smectite clay has been grafted with trimethylpropylammonium (TMPA) groups and the resulting organoclay has been deposited onto a glassy carbon electrode surface as a suitable immobilization matrix for polyphenol oxidase (PPO). High sensitivity of the electrochemical device to catechol biosensing can be achieved when the enzyme was impregnated within the organoclay film subsequent to its deposition due

  4. Interactions between Quaternary Ammonium Surfactant Oligomers and Water-Soluble Modified Guars.

    PubMed

    Kästner; Zana

    1999-10-15

    The interaction between hydroxypropylguar (HPG) and its dodecyl-modified derivative (HMHPG) and cationic surfactant oligomers has been investigated by measurements of the solution viscosity at constant shear rate, microviscosity of the aggregates (dipyrenylpropane fluorescence emission spectra), and aggregation number of the polymer hydrophobe and of the surfactant (time-resolved fluorescence quenching). The surfactants are dodecyltrimethylammonium bromide (DTAB, monomeric surfactant) and some of its dimers and trimers which differed by the carbon number s of the polymethylene spacer connecting the surfactant moieties (2

  5. Solvation effects on cation–p interactions: a test study involving the quaternary ammonium ion

    Microsoft Academic Search

    Carlo Adamo; Gaston Berthier; Roger Savinelli

    2004-01-01

    Water solvation effects on theoretical binding energies of the tetramethylammonium cation with benzene, phenol and indole have been analyzed as a prototype of biological cation–p interactions. Solvent effects were introduced in the quantum chemical computations either by considering molecules belonging to the first solvation of the tetramethylammonium or by a polarizable continuum model. Our results show that the calculated binding

  6. Synthesis and Properties of Piperazine Derivatives and Their Quaternary Ammonium Amphiphilic Salts

    Microsoft Academic Search

    L. H. Gan; G. Roshan Deen; Y. Y. Gan; C. H. Chew

    1996-01-01

    A series of long-chain piperazine derivatives,N-alkyl-N?-methyl piperazine and their amphiphilic salts,N-alkyl-N?-ethyl-N?-methyl piperazinium bromide, and the relatedN-alkyl-N,N?-dimethyl piperazinium bromide were synthesized and characterized by1H and13C NMR and FTIR spectroscopy. Under the experimental conditions used, the NMR data showed unequivocally that quaternarization ofN-alkyl-N?-methyl piperazine by the reaction with ethyl bromide occurred exclusively at the nitrogen atom bearing the methyl group due to

  7. Quaternary ammonium functionalized clay film electrodes modified with polyphenol oxidase for the sensitive detection of catechol.

    PubMed

    Mbouguen, Justin Kemmegne; Ngameni, Emmanuel; Walcarius, Alain

    2007-09-30

    Naturally occurring Cameroonian smectite clay has been grafted with trimethylpropylammonium (TMPA) groups and the resulting organoclay has been deposited onto a glassy carbon electrode surface as a suitable immobilization matrix for polyphenol oxidase (PPO). High sensitivity of the electrochemical device to catechol biosensing can be achieved when the enzyme was impregnated within the organoclay film subsequent to its deposition due to favorable electrostatic interaction between PPO and the TMPA-clay layer. The bioelectrode preparation method was also compatible with the use of a mediator (i.e., ferrocene) and the best performance was obtained with a three-layer configuration made of glassy carbon coated with a first layer of ferrocene (Fc), which was then covered with the PPO-impregnated TMPA-clay layer, and finally overcoated with an enzyme-free TMPA-clay film acting as a protecting overlayer to avoid leaching of the biomolecule in solution. The electrochemical behavior of the modified film electrodes was first characterized by cyclic voltammetry and, then, they were evaluated for the amperometric biosensing of the model analyte catechol in batch conditions and in flow injection analysis. Various experimental parameters likely to influence the biosensor response have been investigated, including the electrode preparation mode (composition configuration, thickness), the usefulness of a mediator, the operating potential and pH of the medium, as well as the advantageous features of the TMPA-clay in comparison to related film electrodes based on non-functionalized clays. The organoclay was found to provide a favorable environment to enzyme activity and the multilayer configuration of the film electrode to provide a biosensor with good characteristics, such as an extended linear range for catechol detection (2 x 10(-8) to 1.2 x 10(-5)M) and a detection limit in the nanomolar range (9 x 10(-9)M). PMID:17537626

  8. Sphere?to?Rod Transitions in Cationic Micelles: Quaternary Ammonium Halides+Phenol+Water Systems

    Microsoft Academic Search

    Kirankumar N. Panchal; Ajit Desai; Tapeshwar Nagar

    2006-01-01

    Viscosity measurements on aqueous micellar solutions of cationic surfactants containing phenol with and without sodium bromide were made to study the sphere?to?rod transitions. Effect of surfactant structure (nonpolar tail, polar head group sizes and counterion), temperature, and phenol and sodium bromide concentration on the viscosity behavior of the surfactant solution is discussed. The sphere?to?rod transition is usually indicated by a

  9. 40 CFR 721.10666 - Quaternary ammonium compounds, bis(fattyalkyl) dimethyl, salts with tannins (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...bis(fattyalkyl) dimethyl, salts with tannins (generic). 721.10666 Section...bis(fattyalkyl) dimethyl, salts with tannins (generic). (a) Chemical substance...bis(fattyalkyl) dimethyl, salts with tannins (PMN P-12-437) is subject to...

  10. 40 CFR 721.10666 - Quaternary ammonium compounds, bis(fattyalkyl) dimethyl, salts with tannins (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...bis(fattyalkyl) dimethyl, salts with tannins (generic). 721.10666 Section...bis(fattyalkyl) dimethyl, salts with tannins (generic). (a) Chemical substance...bis(fattyalkyl) dimethyl, salts with tannins (PMN P-12-437) is subject to...

  11. Determination of quaternary ammonium pesticides by liquid chromatography-electrospray tandem mass spectrometry.

    PubMed

    Castro, R; Moyano, E; Galceran, M T

    2001-04-20

    A method for the direct determination of paraquat, diquat, chlormequat and difenzoquat in water samples, using an on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry system was developed. No sample preparation was required and the detection limits were below the European Union maximum residue levels. The chromatographic separation was performed using an XTera MS C8 column. The concentration of the ion pair reagent, the pH and the gradient elution were optimized to give high recoveries and good chromatographic resolution between quats. The detection was carried out using an ion trap as mass analyzer. Parameters such as the magnitude and duration of the resonant excitation voltage and the magnitude of the trapping RF voltage for full scan tandem mass spectrometry (MS-MS) experiments were studied to establish the optimal experimental conditions. Moreover, the accurate optimization of these parameters allowed MS-MS experiments of low mass ions, below m/z 200, providing unambiguous peak identification. Finally, the reproducibility of the proposed method was shown by good run-to-run and day-to-day precision values and its applicability to the determination of quats in drinking water was evaluated using spiked samples. PMID:11358204

  12. Ammonium repression of nitrate reductase formation in Lemna minor L

    Microsoft Academic Search

    T. O. Orebamjo; G. R. Stewart

    1975-01-01

    The presence of ammonium is shown to inhibit the nitrate-promoted formation of nitrate reductase in Lemna minor L. The ammonium inhibition does not result from an inhibition of nitrate accumulation. The kinetics of the ammonium inhibition suggest it is not a direct effect of ammonium. The inhibition could result from the build up of a product of ammonium assimilation or

  13. Equilibrium studies of sodium-ammonium potassium-ammonium, and calcium-ammonium exchanges on clinoptilolite zeolite

    SciTech Connect

    Jama, M.A.; Yuecel, H. (Middle East Technical Univ., Ankara (Turkey))

    1989-12-01

    Forward and reverse ion-exchange isotherms for the binary sodium-ammonium, potassium-ammonium, and calcium-ammonium systems on clinoptilolite have been measured in aqueous solutions at a total concentration of 0.1 equiv/dm{sup 3} and at 298 K. Prior to exchange experiments it was attempted to prepare homoionic forms of the zeolite by exhaustive treatments with appropriate salt solutions of cations. With no binary exchanges, full replacement of the cation by the ammonium ion is observed, which conflicts with some earlier work on clinoptilolite. Despite the observed partial exchange levels, clinoptilolite shows a very high preference for ammonium ion over sodium and calcium but not over potassium. Thermodynamic values for the exchanges were calculated and compared with data in the literature. Both the selectivity and thermodynamic affinity sequence, in agreement with previous work reported in the literature, are K{sup +} > NH{sub 4}{sup +} > Na{sup +} > Ca{sup 2+}.

  14. Effect of ammonium sulfate, ammonium chloride and root-zone acidity on inorganic ion content of tobacco

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

    1990-01-01

    Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH4)2SO4 or NH4Cl at root-zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH4+ source or root-zone pH. Plants supplied with NH4Cl accumulated up to 1.2 mM Cl g DW-1, but accumulated 37% less inorganic H2PO4- and 47% less SO4(2-) than plants supplied with (NH4)2SO4. The large Cl- accumulation resulted in NH4Cl- supplied plants having a 31% higher inorganic anion (NO3-, H2, PO4-, SO4(2-), and Cl-) charge. This higher inorganic anion charge in the NH4Cl-supplied plants was balanced by a similar increase in K+ charge. Plants supplied with NH4Cl accumulated greater concentrations of Cl- in leaves (up to 5.1% of DW) than plants supplied with (NH4)2SO4 (less than -% DW). Despite the high Cl- concentration of leaves in NH4Cl supplied plants, these plants showed no symptoms of Cl- toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl- concentration in tissue and NH4+ nutrition. The increase in root-zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.

  15. Ammonium content and buoyancy in midwater cephalopods

    E-print Network

    Thuesen, Erik V.

    Ammonium content and buoyancy in midwater cephalopods Brad A. Seibela,*, Shana K. Goffredib , Erik the cation concentrations in several midwater cephalopod species. High NH4 + levels were confirmed in cephalopods is the exchange of sodium for ammonium ions creating low-density fluids that impart lift (Clarke

  16. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  17. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  18. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  19. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  20. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  1. 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.

  2. Effect of ammonium nitrate on precipitation of Ammonium Di-Uranate (ADU) and its characteristics

    NASA Astrophysics Data System (ADS)

    Paik, Shrishma; Biswas, S.; Bhattacharya, S.; Roy, S. B.

    2013-09-01

    Effect of ammonium nitrate on precipitation of Ammonium Di-Uranate (ADU) from nitric acid medium via gaseous ammonia route had been investigated. Studies on effect of ammonium nitrate on precipitation time, particle size, shape, surface morphology, flowability, oxygen/uranium (O/U) ratio and tap density of calcined ADU were carried out at various ammonium nitrate concentrations. It was observed that, the presence of excess ammonium nitrate influences the precipitation time, particle size distribution and surface morphology of the ADU. ADU and uranium oxide were characterized with Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). Presence of ammonium nitrate during precipitation leads to the formation of bigger, porous and uniform particles as compared to the ADU prepared without ammonium nitrate additions.

  3. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

  4. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

  5. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

  6. 78 FR 32690 - Certain Ammonium Nitrate From Ukraine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ...Review)] Certain Ammonium Nitrate From Ukraine Determination On the basis of the record...order on certain ammonium nitrate from Ukraine would be likely to lead to continuation...entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

  7. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  8. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  9. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  10. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  11. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  12. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  13. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  14. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  15. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  16. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  17. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184...Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4 H2 PO4 , CAS...

  18. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...glufosinate-ammonium (butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...3-methylphosphinico-propionic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  19. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  20. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  1. Molecular Structure of Barium Chloride

    NSDL National Science Digital Library

    2002-08-15

    Barium Chloride was the byproduct of the discovery of radium by Madame Curie. When refining radium, the final separation resulted in barium chloride and radium chloride. Electrophoresis of barium chloride produces small-scale amounts of barium atom. This can be used for obtaining barium for commercial uses. Applications of barium chloride include stimulating the heart and other muscles for medicinal purposes, and also for softening water. Other uses of barium chloride include the manufacturing of barium salts, as pesticide, pigments, boiler detergent, in purifying sugar, as mordant in dyeing and printing textiles, and in the manufacture of caustic soda, polymers, and stabilizers.

  2. The comparison of cation-anion interactions of phosphonium- and ammonium-based ionic liquids - A theoretical investigation

    NASA Astrophysics Data System (ADS)

    Lü, Renqing; Lin, Jin; Lu, Yukun; Liu, Dong

    2014-03-01

    The phosphonium- and ammonium-based ionic liquids combined with three anions, such as chloride, tetrafluoroborate and trifluoromethanesulfonate were used to perform a systematic study by theoretical method. The results demonstrate that the cation-anion interaction energies between phosphonium-based ionic liquids are slightly larger than that of their analogues. The larger phosphonium cations can form associated species that chloride, tetrafluoroborate, and trifluoromethanesulfonate anions are able to approach the centre of positive charge more closely than it can in the equivalent nitrogen-based cation due to the less steric effect of phosphorium cation.

  3. Phase diagram of ammonium nitrate

    SciTech Connect

    Dunuwille, Mihindra; Yoo, Choong-Shik, E-mail: csyoo@wsu.edu [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)] [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)

    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.

  4. Ionic liquid electrolytes based on multi-methoxyethyl substituted ammoniums and perfluorinated sulfonimides: Preparation, characterization, and properties

    Microsoft Academic Search

    Hong-Bo Han; Kai Liu; Shao-Wei Feng; Si-Si Zhou; Wen-Fang Feng; Jin Nie; Hong Li; Xue-Jie Huang; Hajime Matsumoto; Michel Armand; Zhi-Bin Zhou

    2010-01-01

    New functionalized ionic liquids (ILs), comprised of multi-methoxyethyl substituted quaternary ammonium cations (i.e. [N(CH2CH2OCH3)4?n(R)n]+; n=1, R=CH3OCH2CH2; n=1, R=CH3, CH2CH3; n=2, R=CH3CH2), and two representative perfluorinated sulfonimide anions (i.e. bis(fluorosulfonyl)imide (FSI?) and bis(trifluoromethanesulfonyl)imide (TFSI?)), were prepared. Their fundamental properties, including phase transition, thermal stability, viscosity, density, specific conductivity and electrochemical window, were extensively characterized. These multi-ether functionalized ionic liquids exhibit good

  5. Quantum description of quaternary nuclear fission

    Microsoft Academic Search

    S. G. Kadmensky; O. V. Smolyansky

    2007-01-01

    The quantum theory of binary and ternary fission is generalized to the case of recently observed quaternary nuclear fission.\\u000a Formulas for the amplitudes of partial fission widths and angular and energy distributions of quaternary fission products\\u000a are derived with allowance for strong channel coupling. The nonevaporation mechanism for formation of light particles is used\\u000a to explain the experimentally observed decrease

  6. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    PubMed

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-01

    The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment. PMID:25587644

  7. SOURCE ASSESSMENT: POLYVINYL CHLORIDE

    EPA Science Inventory

    This report summarizes data on air emissions from the polyvinyl chloride (PVC) industry. PVC is manufactured by 20 companies at 35 plants. Each plant uses one or more of four possible polymerization processes: (1) suspension polymerization, (2) emulsion polymerization, (3) bulk p...

  8. 77 FR 59106 - Glufosinate Ammonium; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ...subchronic study were increased liver and kidney weights with increases in serum aspartate amino transferase and alkaline phosphatase. Additional toxicity testing was conducted with the L-isomer of glufosinate ammonium, and degradates...

  9. 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.

  10. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...sulfate ((NH4 )2 SO4 , CAS Reg. No. 7783-20-2) occurs naturally and consists of colorless or white, odorless crystals or granules. It is prepared by the neutralization of sulfuric acid with ammonium hydroxide. (b) The...

  11. 21 CFR 184.1135 - Ammonium bicarbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...bicarbonate (NH4 HCO3 , CAS Reg. No. 1066-33-7) is prepared by reacting gaseous carbon dioxide with aqueous ammonia. Crystals of ammonium bicarbonate are precipitated from solution and subsequently washed and dried. (b) The ingredient...

  12. Chloride Channels of Intracellular Membranes

    PubMed Central

    Edwards, John C.; Kahl, Christina R.

    2010-01-01

    Proteins implicated as intracellular chloride channels include the intracellular ClC proteins, the bestrophins, the cystic fibrosis transmembrane conductance regulator, the CLICs, and the recently described Golgi pH regulator. This paper examines current hypotheses regarding roles of intracellular chloride channels and reviews the evidence supporting a role in intracellular chloride transport for each of these proteins. PMID:20100480

  13. Sodium Chloride (Catheter Flush) Injection

    MedlinePLUS

    ... use a sodium chloride flush several times a day. Your health care provider will determine the number of sodium chloride flushes you will need a day. ... health care provider probably will give you several days supply of sodium chloride. You will be told ...

  14. Molecular Structure of Thionyl chloride

    NSDL National Science Digital Library

    2002-10-01

    Thionyl chloride is a slightly yellowish liquid with an intense odor and low viscosity. It reacts with lithium to produce lithium chloride and is a good solvent for most organic compounds. Other uses of thionyl chloride include as an intermediate for the production of pharmaceutically active ingredients, as an electrolyte in lithium batteries, and in crop protection.

  15. Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Periparturient hypocalcemia, or milk fever, occurs in dairy cattle when their dietary cation-anion difference (DCAD) is too high. DCAD can be favorably altered to prevent milk fever by either decreasing K and Na or increasing Cl and S in forages for cows in late gestation. The objective of this st...

  16. Evaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer

    E-print Network

    hygroscopic inorganic salts (i.e., ammonium sulfate, ammonium nitrate) which increase in size with increasingEvaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer: Implications for Field National Laboratory, Upon, New York, 11973-5000 Ammonium nitrate is a semivolatile aerosol component under

  17. Memanti­nium chloride 0.1-hydrate

    PubMed Central

    Lou, Wei-Jian; Hu, Xiu-Rong; Gu, Jian-Ming

    2009-01-01

    The crystal structure of the title compound, C12H22N+·Cl?·0.1H2O, consists of (3,5-dimethyl-1-adamantyl)ammonium chloride (memanti­nium chloride) and uncoordinated water mol­ecules. The four six-membered rings of the memanti­nium cation assume typical chair conformations. The Cl? counter-anion links with the memanti­nium cation via N—H?Cl hydrogen bonding, forming channels where the disordered crystal water molecules are located. The O atom of the water mol­ecule is located on a threefold rotation axis, its two H atoms symmetrically distributed over six sites; the water mol­ecule links with the Cl? anions via O—H?Cl hydrogen bonding. PMID:21577595

  18. Tn6188 - A Novel Transposon in Listeria monocytogenes Responsible for Tolerance to Benzalkonium Chloride

    PubMed Central

    Muhterem-Uyar, Meryem; Zaiser, Andreas; Stessl, Beatrix; Guinane, Caitriona M.; Cotter, Paul D.; Wagner, Martin; Schmitz-Esser, Stephan

    2013-01-01

    Controlling the food-borne pathogen Listeria (L.) monocytogenes is of great importance from a food safety perspective, and thus for human health. The consequences of failures in this regard have been exemplified by recent large listeriosis outbreaks in the USA and Europe. It is thus particularly notable that tolerance to quaternary ammonium compounds such as benzalkonium chloride (BC) has been observed in many L. monocytogenes strains. However, the molecular determinants and mechanisms of BC tolerance of L. monocytogenes are still largely unknown. Here we describe Tn6188, a novel transposon in L. monocytogenes conferring tolerance to BC. Tn6188 is related to Tn554 from Staphylococcus (S.) aureus and other Tn554-like transposons such as Tn558, Tn559 and Tn5406 found in various Firmicutes. Tn6188 comprises 5117 bp, is integrated chromosomally within the radC gene and consists of three transposase genes (tnpABC) as well as genes encoding a putative transcriptional regulator and QacH, a small multidrug resistance protein family (SMR) transporter putatively associated with export of BC that shows high amino acid identity to Smr/QacC from S. aureus and to EmrE from Escherichia coli. We screened 91 L. monocytogenes strains for the presence of Tn6188 by PCR and found Tn6188 in 10 of the analyzed strains. These isolates were from food and food processing environments and predominantly from serovar 1/2a. L. monocytogenes strains harboring Tn6188 had significantly higher BC minimum inhibitory concentrations (MICs) (28.5 ± 4.7 mg/l) than strains without Tn6188 (14 ± 3.2 mg/l). Using quantitative reverse transcriptase PCR we could show a significant increase in qacH expression in the presence of BC. QacH deletion mutants were generated in two L. monocytogenes strains and growth analysis revealed that ?qacH strains had lower BC MICs than wildtype strains. In conclusion, our results provide evidence that Tn6188 is responsible for BC tolerance in various L. monocytogenes strains. PMID:24098567

  19. Ice Age refugia and Quaternary extinctions: An issue of Quaternary evolutionary palaeoecology

    NASA Astrophysics Data System (ADS)

    Stewart, John R.; Cooper, Alan

    2008-12-01

    Quaternary palaeoecology, as a discipline, involves the analysis of a large range of fossil organisms from the last ca. 2 million years. This paper considers the role that these Quaternary records can take in better understanding the evolution of those organisms. We also discuss the surprisingly low uptake of evolutionary biology in Quaternary palaeoecological studies. This leads us to encourage an advance on both these fronts with a greater degree of collaboration with phylogeographic and ancient DNA researchers. These discussions accompany a summary of a special issue of Quaternary Science Reviews representing the proceedings of the XVII INQUA held in Cairns Australia in 2007. This special issue includes papers on a wide variety of Quaternary evolutionary palaeoecological and population dynamic subjects including extinct Pacific Island palm trees, Beringian beetles, Scandinavian trees, and the effects on human and animal populations of an extraterrestrial impact event in the Late Glacial of North America.

  20. Anisotropies in Quaternary Intermetallic Compounds

    NASA Astrophysics Data System (ADS)

    Lee, W. C.

    2008-03-01

    From the high-temperature series expansion of magnetic susceptibilities and the anisotropic Weiss temperatures, the first Steven's parameter, B2^0 , and the magnetic exchange interaction constant Jex^ll of each R^=3 ions magnetic sublattice in quaternary intermetallic compounds, RNi2B2C B(R= Tm, Er, Ho, Dy, and Tb) were obtained. The R =Dy system shows the biggest B2^0 value and the R = Tb system does the smallest one. Also we have measured and analyzed the anisotropic M(H) isotherms as a function of applied magnetic fields for H perpendicular and parallel to the c-axis for each compounds to check out our crystalline electric field (CEF) results obtained from the previous mentioned method by using the anisotropic Weiss temperatures. It turned out that most of the temperature dependence of magnetization curve M (T) for H perpendicular the c-axis at low temperature comes from the temperature dependent population of the singlet ground state in group L among groups L(low-lying levels of ground states), H(high levels of ground states), and M(first excited states).

  1. Quaternary glaciation of Mount Everest

    NASA Astrophysics Data System (ADS)

    Owen, Lewis A.; Robinson, Ruth; Benn, Douglas I.; Finkel, Robert C.; Davis, Nicole K.; Yi, Chaolu; Putkonen, Jaakko; Li, Dewen; Murray, Andrew S.

    2009-07-01

    The Quaternary glacial history of the Rongbuk valley on the northern slopes of Mount Everest is examined using field mapping, geomorphic and sedimentological methods, and optically stimulated luminescence (OSL) and 10Be terrestrial cosmogenic nuclide (TCN) dating. Six major sets of moraines are present representing significant glacier advances or still-stands. These date to >330 ka (Tingri moraine), >41 ka (Dzakar moraine), 24-27 ka (Jilong moraine), 14-17 ka (Rongbuk moraine), 8-2 ka (Samdupo moraines) and ˜1.6 ka (Xarlungnama moraine), and each is assigned to a distinct glacial stage named after the moraine. The Samdupo glacial stage is subdivided into Samdupo I (6.8-7.7 ka) and Samdupo II (˜2.4 ka). Comparison with OSL and TCN defined ages on moraines on the southern slopes of Mount Everest in the Khumbu Himal show that glaciations across the Everest massif were broadly synchronous. However, unlike the Khumbu Himal, no early Holocene glacier advance is recognized in the Rongbuk valley. This suggests that the Khumbu Himal may have received increased monsoon precipitation in the early Holocene to help increase positive glacier mass balances, while the Rongbuk valley was too sheltered to receive monsoon moisture during this time and glaciers could not advance. Comparison of equilibrium-line altitude depressions for glacial stages across Mount Everest reveals asymmetric patterns of glacier retreat that likely reflects greater glacier sensitivity to climate change on the northern slopes, possibly due to precipitation starvation.

  2. Chloride channels as drug targets

    PubMed Central

    Verkman, Alan S.; Galietta, Luis J. V.

    2013-01-01

    Chloride channels represent a relatively under-explored target class for drug discovery as elucidation of their identity and physiological roles has lagged behind that of many other drug targets. Chloride channels are involved in a wide range of biological functions, including epithelial fluid secretion, cell-volume regulation, neuroexcitation, smooth-muscle contraction and acidification of intracellular organelles. Mutations in several chloride channels cause human diseases, including cystic fibrosis, macular degeneration, myotonia, kidney stones, renal salt wasting and hyperekplexia. Chloride-channel modulators have potential applications in the treatment of some of these disorders, as well as in secretory diarrhoeas, polycystic kidney disease, osteoporosis and hypertension. Modulators of GABAA (?-aminobutyric acid A) receptor chloride channels are in clinical use and several small-molecule chloride-channel modulators are in preclinical development and clinical trials. Here, we discuss the broad opportunities that remain in chloride-channel-based drug discovery. PMID:19153558

  3. Chloride and Salinity

    NSDL National Science Digital Library

    2011-07-15

    This learning activity from the Advanced Technology Environmental and Energy Center (ATEEC) will provide a good introduction for students studying chloride and salinity. A list of required materials is included as well as the step by step procedure for conducting the experiment. Student worksheets are also included. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

  4. Dioxanates of Cadmium Chloride

    Microsoft Academic Search

    Martin G. Chasanov; Cecil C. Lynch

    1957-01-01

    DIOXANATES of cadmium chloride were precipitated from a solution of the anhydrous salts (certified purity) in acetal-free dioxane, prepared from Eastman Kodak technical 1,4-dioxane by the method of Eigenberger1. The crude dioxanate (that is, wet with dioxane) was placed in the bulb of the isotenoscope of Smith and Menzies2, and oil of paraffin, U.S.P., was employed as the levelling liquid.

  5. 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.

  6. Benzyl­tris­[2-(di­benzyl­amino)­eth­yl]ammonium iodide

    PubMed Central

    Bello, Mollie J.; Brady, Sarah E.; Zakharov, Lev N.; Tyler, David R.

    2014-01-01

    In the title quaternary ammonium salt, C55H61N4 +·I?, all three N,N-di­benzyl­ethanamine, –(CH2)2N(CH2C6H5)2, groups have different conformations. The N—C—C—N torsion angles are significantly different [89.86?(13), 162.61?(10) and 175.70?(10)°] and the dihedral angles between the phenyl rings in these groups are different as well [58.21?(4), 43.73?(4) and 76.72?(5)°]. In the crystal, the I? anions fill empty spaces between the bulky cations. The cations and anions are linked by weak C—H?I inter­actions, forming a chain along [110]. PMID:24526992

  7. 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.

  8. Benchmark binding energies of ammonium and alkyl-ammonium ions interacting with water. Are ammonium-water hydrogen bonds strong?

    NASA Astrophysics Data System (ADS)

    Vallet, Valérie; Masella, Michel

    2015-01-01

    Alkyl-ammonium ion/water interactions are investigated using high level quantum computations, yielding thermodynamics data in good agreement with gas-phase experiments. Alkylation and hydration lead to weaken the NHsbnd O hydrogen bonds. Upon complete hydration by four water molecules, their main features are close to those of the OHsbnd O bond in the isolated water dimer. Energy decomposition analyses indicate that hydration of alkyl-ammonium ions are mainly due to electrostatic/polarization effects, as for hard monoatomic cations, but with a larger effect of dispersion.

  9. 40 CFR 721.10569 - Tricyclic quaternary amine salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Tricyclic quaternary amine salt (generic). 721.10569 Section 721...721.10569 Tricyclic quaternary amine salt (generic). (a) Chemical substance...generically as tricyclic quaternary amine salt (PMN P-08-471) is subject to...

  10. Eutectic composite explosives containing ammonium nitrate

    SciTech Connect

    Stinecipher, M.M.

    1981-01-01

    The eutectic of ammonium nitrate (AN), the ammonium salt of 3,5-dinitro-1,2,4-triazole was prepared and its sensitivity and performance were studied. It was found that this AN formulation was unusual in that it performed ideally at small diameter, which indicated that it was a monomolecular explosive. Sensitivity tests included type 12 impact, Henkin thermal and wedge tests, and performance tests included rate stick/plate dent, cylinder, and aquarium tests. Results were compared with calculations, standard explosives, and another eutectic, ethylendiamine dinitrate (EDD)/AN.

  11. Supercritical water oxidation of ammonium picrate

    SciTech Connect

    LaJeunesse, C.A.; Mills, B.E.; Brown, B.G.

    1994-11-01

    This study demonstrates the feasibility of using supercritical water oxidation to destroy ammonium picrate. Analyses of reactor effluent composition at various temperatures, residence times, and oxidant concentrations were used to design an improved reactor configuration for achieving destruction with minimum corrosion. The engineering evaluation reactor, a room-sized laboratory scale reactor, was reconfigured to incorporate this design change. Destruction of ammonium picrate with minimized corrosion was demonstrated on this reconfigured reactor. Factors that must be considered in scaling up to pilot plant size are discussed.

  12. On the evaporation of ammonium sulfate solution

    PubMed Central

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-01-01

    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. PMID:19861551

  13. 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.

  14. Catalytic enantioselective synthesis of quaternary carbon stereocentres

    NASA Astrophysics Data System (ADS)

    Quasdorf, Kyle W.; Overman, Larry E.

    2014-12-01

    Quaternary carbon stereocentres--carbon atoms to which four distinct carbon substituents are attached--are common features of molecules found in nature. However, before recent advances in chemical catalysis, there were few methods of constructing single stereoisomers of this important structural motif. Here we discuss the many catalytic enantioselective reactions developed during the past decade for the synthesis of single stereoisomers of such organic molecules. This progress now makes it possible to incorporate quaternary stereocentres selectively in many organic molecules that are useful in medicine, agriculture and potentially other areas such as flavouring, fragrances and materials.

  15. Catalytic enantioselective synthesis of quaternary carbon stereocentres.

    PubMed

    Quasdorf, Kyle W; Overman, Larry E

    2014-12-11

    Quaternary carbon stereocentres-carbon atoms to which four distinct carbon substituents are attached-are common features of molecules found in nature. However, before recent advances in chemical catalysis, there were few methods of constructing single stereoisomers of this important structural motif. Here we discuss the many catalytic enantioselective reactions developed during the past decade for the synthesis of single stereoisomers of such organic molecules. This progress now makes it possible to incorporate quaternary stereocentres selectively in many organic molecules that are useful in medicine, agriculture and potentially other areas such as flavouring, fragrances and materials. PMID:25503231

  16. IUPAC-NIST Solubility Data Series. 87. Rare Earth Metal Chlorides in Water and Aqueous Systems. Part 3. Heavy Lanthanides (Gd-Lu)

    NASA Astrophysics Data System (ADS)

    Mioduski, Tomasz; Gumi?ski, Cezary; Zeng, Dewen

    2009-12-01

    This is the third and last part of the volume devoted to solubility data of rare earth metal chlorides in water and in ternary and quaternary aqueous systems. Compilations of all available experimental data for each rare earth metal chloride are introduced with a corresponding critical evaluation. Every such evaluation contains a tabulated collection of all solubility results in water, a scheme of the water-rich part of the equilibrium LnCl3-H2O phase diagram, solubility equation(s), a selection of suggested solubility data, and a brief discussion of the multicomponent systems. Because the ternary and quaternary systems were almost never studied more than once, no critical evaluations or systematic comparisons of such data were possible. Simple chlorides (no complexes) of Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu are treated as the input substances. The literature (including a thorough coverage of papers in Chinese and Russian) has been covered through the middle of 2008.

  17. Molecular Structure of Ferric chloride

    NSDL National Science Digital Library

    2002-08-27

    Ferric chloride is a corrosive chemical, thus, it is used to deodorize sewage and industrial waste by partially reducing to ferrous chloride. It is also employed as an engraving reagent on metal surfaces. Other applications include its use as a flocculating agent in water treatment. Ferric chloride is a hazardous chemical that irritates the skin and eyes and is toxic if ingested, however it can be used as a reagent in pharmaceutical preparations.

  18. 40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

  19. 40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

  20. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). (a...polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (PMN...

  1. 40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

  2. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). (a...polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (PMN...

  3. 40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

  4. 40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

  5. 21 CFR 180.37 - Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...true Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. 180...37 Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. ...additives saccharin, ammonium saccharin, calcium saccharin, and sodium...

  6. MECHANISM BY WHICH AMMONIUM FERTILIZERS KILL LARKSPUR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental concerns of using pesticides on public lands have greatly reduced the use of herbicides to control tall larkspur (Delphinium barbeyi). Alternative methods of control have used ammonium sulfate placed in the crown of individual plants to kill larkspur. The objective of this study was ...

  7. Diamond Head Revisited with Ammonium Dichromate.

    ERIC Educational Resources Information Center

    Arrigoni, Edward

    1981-01-01

    The classroom demonstration using ammonium dichromate to simulate a volcanic eruption can be modified into a more dramatic and accurate representation of the geologic processes involved in the formation of a volcanic crater. The materials, demonstration setup, safety procedures, and applications to instruction are presented. (Author/WB)

  8. Tunicate Eggs Utilize Ammonium Ions for Flotation

    Microsoft Academic Search

    Charles C. Lambert; Gretchen Lambert

    1978-01-01

    Unlike most solitary ascidians, Corella willmeriana retains its eggs and embryos well past hatching. The early stages float to the top of the enlarged atrium from which they cannot escape. Ammonium ions replace other more dense substances in the cell sap of the float cells surrounding the embryo. Energy derived from glycolysis but not mitochondrial processes supports this process.

  9. Review on Thermal Decomposition of Ammonium Nitrate

    Microsoft Academic Search

    Shalini Chaturvedi; Pragnesh N. Dave

    2013-01-01

    In this review data from the literature on thermal decomposition of ammonium nitrate (AN) and the effect of additives to their thermal decomposition are summarized. The effect of additives like oxides, cations, inorganic acids, organic compounds, phase-stablized CuO, etc., is discussed. The effect of an additive mainly occurs at the exothermic peak of pure AN in a temperature range of

  10. Ammonium nitrate: a promising rocket propellant oxidizer

    Microsoft Academic Search

    C. Oommen; S. R. Jain

    1999-01-01

    Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been

  11. 77 FR 47291 - Residues of Didecyl Dimethyl Ammonium Chloride; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ...Dietary Exposure 1. Food. Studies have...University, Commercial Vegetable Production Guides...treatment, and oil field uses. The pond and oil field uses are...drinking water sources. Therefore, the...to residues in food or in...

  12. Surface tension measurements of aqueous ammonium chloride (NH4Cl) in air

    NASA Technical Reports Server (NTRS)

    Lowry, S. A.; Mccay, M. H.; Mccay, T. D.; Gray, P. A.

    1989-01-01

    Aqueous NH4Cl's solidification is often used to model metal alloy solidification processes. The present determinations of the magnitude of the variation of aqueous NH4Cl's surface tension as a function of both temperature and solutal concentration were conducted at 3, 24, and 40 C over the 72-100 wt pct water solutal range. In general, the surface tension increases 0.31 dyn/cm per percent decrease in wt pct of water, and decreases 0.13 dyn/cm for each increase in deg C. Attention is given to the experimental apparatus employed.

  13. Ammonium chloride causes reversible inhibition of low density lipoprotein receptor recycling and accelerates receptor degradation.

    PubMed

    Grant, K I; Casciola, L A; Coetzee, G A; Sanan, D A; Gevers, W; van der Westhuyzen, D R

    1990-03-01

    The effects of the acidotropic agent, NH4Cl, on the recycling and turnover of low density lipoprotein (LDL) receptors were analyzed in human skin fibroblasts using ligand binding assays, [35S]methionine pulse-chase experiments, and electron microscopy. NH4Cl did not prevent receptor internalization but caused a marked redistribution of LDL receptors to intracellular sites (endosomes) that was completely dependent on the presence of apolipoprotein-B- or -E-containing ligands. Maximal inhibition of recycling was observed at LDL concentrations that only partially saturated receptors, suggesting that the receptors function as oligomers. In contrast, full receptor occupancy by the multivalent, apolipoprotein-E-containing beta-very low density lipoprotein was required for the same effect. The intracellular accumulation was reversible and the majority of receptors returned to the cell surface when NH4Cl was removed after short treatments. The rate of degradation of LDL receptors was greatly accelerated in the presence of NH4Cl and ligand, with a t1/2 of about 2 h (approximately 6 times faster than receptor degradation in the absence of NH4Cl). Neither the redistribution nor the accelerated loss of immunoprecipitable LDL receptors was observed in an LDL receptor internalization-defective mutant cell line. We conclude that NH4Cl inhibited the recycling specifically of occupied receptors, thereby accelerating their degradation, probably in endosomes. PMID:2303493

  14. The Optical Constants of Several Atmospheric Aerosol Species: Ammonium Sulfate, Aluminum Oxide, and Sodium Chloride

    Microsoft Academic Search

    Owen B. Toon; James B. Pollack; Bishun N. Khare

    1976-01-01

    The optical constants of substances composing atmospheric aerosols are required to evaluate properly the effects of aerosols on the earth's radiation balance. We briefly review techniques for determining optical constants and also discuss pitfalls in using measured optical constants to simulate the optical constants of the real particles found in the atmosphere. We then compile the optical constants of (NH4hSO4,

  15. Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride

    SciTech Connect

    Magirl, C.S.; Incropera, F.P.

    1993-01-01

    Using 27% aq. NH[sub 4]Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

  16. Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride. Annual performance report

    SciTech Connect

    Magirl, C.S.; Incropera, F.P.

    1993-01-01

    Using 27% aq. NH{sub 4}Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

  17. Journal of Crystal Growth 274 (2005) 233240 Shape of ammonium chloride dendrite tips at small

    E-print Network

    Lahiri, Mayank

    2005-01-01

    exploration of different tip shape models for dendrites resulting from phase-field simulations was reported grown from supersaturated aqueous solution. For growth at small supersaturation, we compare two models observed microstruc- tural form resulting from the diffusion-limited solidification of non

  18. The role of the anion in the reaction of reducing sugars with ammonium salts.

    PubMed

    Agyei-Aye, Kwasi; Chian, May X; Lauterbach, John H; Moldoveanu, Serban C

    2002-11-19

    Reactions of reducing sugars with ammonia and its compounds are important commercially, particularly in the preparation of flavors and caramel colors. However, such reactions generally produce a complex series of products ranging from simple molecules to complex polymeric materials, particularly since commercial systems generally involve mixtures of sugars as opposed to single sugars. This complexity has made understanding the mechanisms of such reactions difficult. Therefore, investigatory work has generally been focused on model systems. Herein we report one such study with model systems: the effects of the nature of the anion of the reactions of reducing sugars with ammonium salts. D-Glucose was reacted in aqueous solution with each of the following ammonium salts: acetate, bicarbonate, carbonate, chloride, citrate, formate, monohydrogenphosphate (DAP), sulfate, and sulfite. These reactions were carried out in a Parr bomb at 93 degrees C for 2.5 h. The initial pH of the reaction mixtures was adjusted to pH 8.0 at 25 degrees C. The resulting mixtures were analyzed by LC-MS, and the results were analyzed by comparing the product yields and distributions with those obtained with DAP. The major reaction product of interest was 2,6-deoxyfructosazine, as it had been shown to be a marker for the polymeric material formed from such reactions. It was found that ammonium salts of weak acids were much more effective in effecting the desired reactions than were those of strong acids; however, none was as effective as DAP. PMID:12433492

  19. Antibacterial and Hemolytic Activities of Quaternary Pyridinium

    E-print Network

    bacteria but not mammalian cells.[2­4] Polymers have been used as antimicrobial agents due commonly used as biocidal agents.[6­15] A number of polymeric disinfectants based on quaternary pyridinium bacteria. Recently, Gao and coworkers synthesized random copolymers of acrylamide and vinyl pyridine

  20. Enantioselective construction of remote quaternary stereocentres

    NASA Astrophysics Data System (ADS)

    Mei, Tian-Sheng; Patel, Harshkumar H.; Sigman, Matthew S.

    2014-04-01

    Small molecules that contain all-carbon quaternary stereocentres--carbon atoms bonded to four distinct carbon substituents--are found in many secondary metabolites and some pharmaceutical agents. The construction of such compounds in an enantioselective fashion remains a long-standing challenge to synthetic organic chemists. In particular, methods for synthesizing quaternary stereocentres that are remote from other functional groups are underdeveloped. Here we report a catalytic and enantioselective intermolecular Heck-type reaction of trisubstituted-alkenyl alcohols with aryl boronic acids. This method provides direct access to quaternary all-carbon-substituted ?-, ?-, ?-, ?- or ?-aryl carbonyl compounds, because the unsaturation of the alkene is relayed to the alcohol, resulting in the formation of a carbonyl group. The scope of the process also includes incorporation of pre-existing stereocentres along the alkyl chain, which links the alkene and the alcohol, in which the stereocentre is preserved. The method described allows access to diverse molecular building blocks containing an enantiomerically enriched quaternary centre.

  1. Quaternary Geochronology 2 (2007) 290295 Research paper

    E-print Network

    Long, Bernard

    at the beginning of the Last Interglacial. These are in good agreement with the 10 Be cosmogenic dates obtained of the strongest ever recorded intracontinental earthquakes (magnitude 8.3 on Richter scale). PreviousQuaternary Geochronology 2 (2007) 290­295 Research paper Luminescence dating of a gigantic

  2. Quaternary geology of the Amazonian Lowland

    Microsoft Academic Search

    Georg Irion; Jens Müller; Jose Nunes de Mello; Wolfgang J. Junk

    1995-01-01

    The Quaternary history of the Amazon lowlands is characterized by deposition of sediments of Andean provenance and by the influences of changing sea levels. Areas well above the present water tables were not reached by Pleistocene high-water stages. These areas have been intensively weathered since the Tertiary, forming hard lateritic weathering horizons. These weathering horizons are best explained by the

  3. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized product is filtered, washed...pigment consists principally of ferric ammonium ferrocyanide with smaller amounts of...

  4. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized product is filtered, washed...pigment consists principally of ferric ammonium ferrocyanide with smaller amounts of...

  5. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized product is filtered, washed...pigment consists principally of ferric ammonium ferrocyanide with smaller amounts of...

  6. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized product is filtered, washed...pigment consists principally of ferric ammonium ferrocyanide with smaller amounts of...

  7. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized product is filtered, washed...pigment consists principally of ferric ammonium ferrocyanide with smaller amounts of...

  8. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt...equivalent of 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium...

  9. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt...equivalent of 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium...

  10. Ammonium tris­(tetra­ethyl­ammonium) hexa­cosa­oxidoocta­molybdate

    PubMed Central

    Zebiri, Ikram; Bencharif, Leïla; Direm, Amani; Bencharif, Mustapha; Benali-Cherif, Nourredine

    2008-01-01

    The structure of the title compound, NH4(C8H20N)3[Mo8O26], is built up by discrete cations and anions, with two formula units in the asymmetric unit. The ?-octa­molybdate anions are linked to the ammonium cations via N—H?O hydrogen bonding involving terminal oxide groups and to the tetra­ethyl­ammonium cations via weak C—H?O inter­actions. PMID:21201863

  11. Molecular Structure of Picryl chloride

    NSDL National Science Digital Library

    2002-09-20

    Picryl chloride is ranked as one of the 100 most commonly found explosive and shock sensitive materials. It is made by reacting 2,4,6 trinitrophenol with thionyl chloride. This highly reactive compound is known to be hazardous and toxic, and to cause liver injury in mice. It is often used as a sensitization agent in mice when their cells undergo hypersensitivity studies.

  12. Ammonium inactivation of nitrate reductase in Lemna minor L

    Microsoft Academic Search

    T. O. Orebamjo; G. R. Stewart

    1975-01-01

    The addition of ammonium to nitrate induced plants of Lemna minor L. brings about a rapid loss in extractable nitrate reductase activity. This inactivation is reversible both in vivo and in vitro. Inhibitors of RNA and protein synthesis do not protect nitrate reductase against ammonium inactivation. It is suggested that factors, in addition to ammonium ions, are components of the

  13. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Drugs 6 2011-04-01 2011-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

  14. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Drugs 6 2012-04-01 2012-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

  15. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Drugs 3 2013-04-01 2013-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

  16. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Drugs 6 2014-04-01 2014-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

  17. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Drugs 3 2014-04-01 2014-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

  18. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Drugs 3 2012-04-01 2012-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

  19. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Drugs 3 2011-04-01 2011-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

  20. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Drugs 6 2013-04-01 2013-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

  1. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 ...721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant...generically as alkyl phosphonate ammonium salts (PMNs P-93-725 and...

  2. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 ...721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant...generically as alkyl phosphonate ammonium salts (PMNs P-93-725 and...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Tetra alkyl ammonium salt (generic). 721.10430 Section 721... § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance...identified generically as tetra alkyl ammonium salt (PMN P-97-823) is subject to...

  4. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

  5. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Drugs 3 2010-04-01 2009-04-01 true Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

  6. STUDIES ON THE EFFECT OF AMMONIUM SULFATE ON CARCINOGENESIS

    EPA Science Inventory

    The project was designed to evaluate the health effects of ammonium sulfate (Nh4)2 SO4 inhalation using experimental animals. The questions studied were: (1) Is inhaled ammonium sulfate co-carcinogenic. (2) What are the deposition and clearance patterns of inhaled ammonium sulfat...

  7. Effect of ammonium ion distribution on Nafion ® conductivity

    Microsoft Academic Search

    Kitiya Hongsirikarn; Thirapong Napapruekchart; Xunhua Mo; James G. Goodwin Jr.

    2011-01-01

    Nafion® conductivity in a proton exchange membrane fuel cell (PEMFC) with the fuel stream containing ammonia is mainly affected by the ammonium ion composition and operating conditions. In this study, the effect of ammonium ion distribution on Nafion conductivity was investigated for the first time. The conductivities of two kinds of contaminated membranes having uniform and non-uniform ammonium ion distributions

  8. Benzalkonium Chloride and Glaucoma

    PubMed Central

    Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Abstract Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology. PMID:24205938

  9. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 2010-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements...

  10. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric chloride hexahydrate (iron (III) chloride...o)(12) of this chapter, with no limitation other than current good manufacturing practice. (d) Prior sanctions for...

  11. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric chloride hexahydrate (iron (III) chloride...o)(12) of this chapter, with no limitation other than current good manufacturing practice. (d) Prior sanctions for...

  12. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric chloride hexahydrate (iron (III) chloride...o)(12) of this chapter, with no limitation other than current good manufacturing practice. (d) Prior sanctions for...

  13. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric chloride hexahydrate (iron (III) chloride...o)(12) of this chapter, with no limitation other than current good manufacturing practice. (d) Prior sanctions for...

  14. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Agriculture 3 2011-01-01 2011-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  15. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Agriculture 3 2013-01-01 2013-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  16. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Agriculture 3 2012-01-01 2012-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  17. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Agriculture 3 2014-01-01 2014-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  18. 21 CFR 182.8252 - Choline chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Choline chloride. 182.8252 Section 182.8252 Food...RECOGNIZED AS SAFE Nutrients § 182.8252 Choline chloride. (a) Product. Choline chloride. (b) Conditions of use. This...

  19. 21 CFR 182.8252 - Choline chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Choline chloride. 182.8252 Section 182.8252 Food...RECOGNIZED AS SAFE Nutrients § 182.8252 Choline chloride. (a) Product. Choline chloride. (b) Conditions of use. This...

  20. 21 CFR 182.8252 - Choline chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Choline chloride. 182.8252 Section 182.8252 Food...RECOGNIZED AS SAFE Nutrients § 182.8252 Choline chloride. (a) Product. Choline chloride. (b) Conditions of use. This...