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Fragmentation mechanism of alkyl- monoglycosides by mass spectrometry / N. A. Sayed in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 217-221 Titre : Fragmentation mechanism of alkyl- monoglycosides by mass spectrometry Type de document : texte imprimé Auteurs : N. A. Sayed, Auteur ; M. M. A. El-Sukkary, Auteur ; W. I. M. El-Azab, Auteur Année de publication : 2010 Article en page(s) : p. 217-221 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Aglucone Alkyl polyglycosides Spectrométrie de masse Surfactants Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Alkylmonoglycosides with different alkyl chain lengths (APG8, APG9, APG10 and APG14) were prepared by Fisher reaction of glucose with fatty alcohols. Excess alcohol was used to increase the possibility of producing alkyl monoglycosides products. Mass spectrometry with chemical ionization was used to confirm their structures as alkyl monoglycosides. Accordingly, the obtained signals at m/z = 293, 307, 321 and 377 corresponds to their protonated molecules. The base lines which are the most intensive signals in each spectrum at m/z = 145, 127, 141 and 197 represent the most abundant ions and define the pathway of their fragmentation mechanism. The mass 145 for APG8 is generated from the parent ion by elimination of the mass ROH followed by H2O. For this compound cleavage occurs at the C–O bond next to the glucose ring, while fragmentation of alkyl monoglycosides with carbon number 9, 10 and 14 occurs at the O–R bond releasing the alkyl cation R of the aglucone moiety (CnH2n+1) along with large fragment ions characteristic of the glucose moiety. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9799 [article]

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Concentrations of Endocrine Disrupting Alkylphenols and Their mono- and diethoxylates in sediments and water from artificial lake Malta in Poland / A. Zgola-Grzeskowiak in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 222-227 Titre : Concentrations of Endocrine Disrupting Alkylphenols and Their mono- and diethoxylates in sediments and water from artificial lake Malta in Poland Type de document : texte imprimé Auteurs : A. Zgola-Grzeskowiak, Auteur ; T. Grzeskowiak, Auteur ; R. Rydlichowski, Auteur ; Z. Lukaszewski, Auteur Année de publication : 2010 Article en page(s) : p. 222-227 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alkylphénols Eau -- Pollution Ethoxylate d'alkylphénol Extraction par ultrasons Sédiments contaminés Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : In the present paper analysis of alkylphenols and their short-chained ethoxylates was presented. The analytes were determined in sediments from Lake Malta as well as in water incoming to and outgoing from the lake. Sonication-assisted extraction was used for isolation of the analytes from the sediment samples. Solid-phase extraction with polytetrafluoroethylene sorbent was used for both clean-up of extracts and isolation of analytes from the water samples. Alkylphenols and their ethoxylates were quantitatively analysed with the use of HPLC with fluorescence detection. The analytes were determined in the sediment samples at relatively low concentrations with the maximum concentration of 168 μg kg–1 for nonylphenol monoethoxylate, which can be ascribed to periodic removal of sediments from Lake Malta. Maximum concentration in water samples was noted for nonylphenol at 0.56 μg L–1. No octylphenol nor its ethoxylates were found in the water samples. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9800 [article]

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Synthesis of 1,1,1-triethoxycarbonyl-3- [2-(F-alkyl)-ethyl]propanes and 1,1,q,q-tetraalkoxycarbonyl-1,q-di-[2-(F-alkyl)-ethyl]alcanes as precursors of anionic surfactants / H. Trabelsi in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 228-231 Titre : Synthesis of 1,1,1-triethoxycarbonyl-3- [2-(F-alkyl)-ethyl]propanes and 1,1,q,q-tetraalkoxycarbonyl-1,q-di-[2-(F-alkyl)-ethyl]alcanes as precursors of anionic surfactants Type de document : texte imprimé Auteurs : H. Trabelsi, Auteur ; M. Nasreddine, Auteur ; S. Y. Dieng, Auteur ; F. Szönyi, Auteur ; S. Szönyi, Auteur Année de publication : 2010 Article en page(s) : p. 228-231 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Catalyse par transfert de phase Perfluoroalkyles Surfactants -- Synthèse Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : 1,1,1-triethoxycarbonyl-3-[2-(F-alkyl)-ethyl]propanes and 1,1,q,q-tetraalkoxycarbonyl-1,q-di-[2-(F-alkyl)-ethyl]alcanes were prepared from 2-(F-alkyl)-ethyl iodides in a one-step procedure involving a Solid-Liquid Phase Transfer Catalysis. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9801 [article]

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Synthesis and properties of di-n-hexadecyl-a,ω-alkyl bisphosphate surfactants / P. Tyagi in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 232-237 Titre : Synthesis and properties of di-n-hexadecyl-a,ω-alkyl bisphosphate surfactants Type de document : texte imprimé Auteurs : P. Tyagi, Auteur ; R. Tyagi, Auteur Année de publication : 2010 Article en page(s) : p. 232-237 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants Tags : Surfactants  'Hexadecyl  phosphate'  '1,4-dibromo  butane'  1,6-dibromo  hexane'  '1,8-dibromo  octane'  'Bis  phosphoric  acid' Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Amphipatic compounds with connecting group between two lipophilic groups were prepared by phosphorylating a long chain alcohol (hexadecanol) with pyrophosphoric acid to prepare hexadecyl phosphate. Then the resulting hexadecyl phosphate was used to prepare bisphosphate surfactants with terminal dibromo alkanes viz. 1,4-dibromo butane or 1,6-dibromo hexane or 1,8-dibromo octane using acetonitrile as solvent. The structure of synthesized products were verified by modern analytical techniques viz. FT-IR, and 1H-NMR. The disodium salts of bisphosphate surfactants were obtained by neutralization of free acid with sodium hydroxide. The performance properties viz. foaming, wetting, emulsifying ability and anionic content of synthesized surfactants were also evaluated. The synthesized bisphosphate surfactant with 1,6-dibromo hexane possessed maximum anionic content and showed good water solubility, foaming, wetting, and emulsifying ability compared to conventional analogs. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9802 [article]

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Study of glycerol and sweet water as a carbon source for production of ramnolipids by naturally occurring strains of pseudomonas aeruginosa (ATCC 10145 and ATCC 9027) / S. Wadekar in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 238-241 Titre : Study of glycerol and sweet water as a carbon source for production of ramnolipids by naturally occurring strains of pseudomonas aeruginosa (ATCC 10145 and ATCC 9027) Type de document : texte imprimé Auteurs : S. Wadekar, Auteur ; S. Patil, Auteur ; A. M. Lali, Auteur ; D. N. Bhowmick, Auteur ; Ashish Pratap Singh, Auteur Année de publication : 2010 Article en page(s) : p. 238-241 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants Tags : Surfactant  Rhamnolipides  'Pseudomonas  aeruginosa'  'Croissance  bactérienne'  Glycérol  'Traitement  différé'  Optimisation Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The interest in biosurfactant has increased considerably due to their large potential for industrial applications. Rhamnolipid is a simplest class of biosurfactants with well defined structure. The main obstacle in commercialization of biosurfactant especially rhamnolipids is the higher cost of the production. Glycerol is readily available from commercial fat-splitting process in the form of sweet water (up to 20% w/v) at very low cost. Two natural strains of Pseudomonas aeruginosa (ATCC 10145 and ATCC 9027) were compared for rhamnolipid production. The neotype strain of Pseudomonas aeruginosa (ATCC 10145) was found to produce more amounts of rhamnolipids than Pseudomonas aeruginosa (ATCC 9027) on glucose and glycerol as carbon source. The microbial growth (0.94 g/L) and formation of rhamnolipids (2.75 g/L) was maximum at 5% (w/v) glycerol concentration by Pseudomonas aeruginosa (ATCC 10145). The fermentation was monitored for 8 days on shake flask and magnetically stirred batch culture. In magnetically stirred batch culture, microbial growth was 0.69 g/L and 2.73 g/L of rhamnolipid was formed. Sweet water was also used as a source of glycerol. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9803 [article]

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Study on the synthesis and surface activities of novel alkyl sulfonate eemini surfactants / X. Li in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 243-247 Titre : Study on the synthesis and surface activities of novel alkyl sulfonate eemini surfactants Type de document : texte imprimé Auteurs : X. Li, Auteur ; S. Zhao, Auteur ; Z. Hu, Auteur ; H. Zhu, Auteur ; D. Cao, Auteur Année de publication : 2010 Article en page(s) : p. 243-247 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants -- Synthèse Tension superficielle Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Three novel dialkyl disulfonate gemini surfactants (Cn-6-Cn, n = 6, 8, 12; n is carbon number of hydrophobic chain) were synthesized from cyanuric chloride, aliphatic amine and taurine. The chemical structures of the prepared compounds were confirmed by 1H NMR, 13C NMR, IR spectra and ESI-MS. Their critical micelle concentrations (CMC) in the aqueous solutions at 25°C were determined by surface-tension method. With the increasing length of the hydrophobic carbon chain, the values of their CMC decreased. The surface tension measurements of Cn-6-Cn give low CMC, great efficiency in lowering the surface tension, and strong adsorption at air–water interface. In addition, adsorption and micellization behavior of Cn-6-Cn were estimated by the parameter of pC20, the minimum average area per surfactant molecule (Amin). Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9804 [article]

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Synergistic effect of cationic-nonionic surfactants on simultaneous separation of phenylalanine and tyrosine / A. Mohammad in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 248-253 Titre : Synergistic effect of cationic-nonionic surfactants on simultaneous separation of phenylalanine and tyrosine Type de document : texte imprimé Auteurs : A. Mohammad, Auteur ; N. Haq, Auteur Année de publication : 2010 Article en page(s) : p. 248-253 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Acides aminés Les acides aminés (ou aminoacides) sont une classe de composés chimiques possédant deux groupes fonctionnels : à la fois un groupe carboxyle –COOH et un groupe amine –NH2. Parmi ceux-ci, les acides α-aminés se définissent par le fait que leur groupe amine est lié à l'atome de carbone adjacent au groupe acide carboxylique (le carbone α), ce qui leur confère la structure générique H2N–CHR–COOH, où R représente la chaîne latérale, qui identifie l'acide α-aminé. Les acides α-aminés jouent un rôle fondamental en biochimie comme constituants élémentaires des protéines : ils polymérisent en formant des liaisons peptidiques qui aboutissent à de longues chaînes macromoléculaires appelées peptides. Chromatographie sur couches minces Matériaux -- Imprégnation Séparation (technologie) Surfactants Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : A new thin layer chromatographic system comprising of silica gel impregnated with 0.1% aqueous solution (below CMC) of nonionic surfactant Brij-35 as stationary phase and 0.1% aqueous solution (below CMC) of cationic surfactant (cetrimide) as eluent has been found most suitable for the separation of closely related amino acids (phenylalanine and tyrosine) from their mixture. Effect of substitution of Brij-35 by cetrimide and sodium cholate has been examined to assess the impact of charge of impregnant on the chromatographic behavior of analytes. The changes brought about by the impregnation in the structure and homogeneity of silica gel have been studied by scanning electron microscopy (SEM) and fourier transform infra-red spectroscopy (FTIR) techniques. Optimizations of concentration of Brij-35 and cetrimide in the stationary and mobile phases respectively and the effect of bed height on the separation have also been examined. Chromatographic parameters like ΔRF, separation factor (α) and resolution (RS) were calculated for the separation of tyrosine from phenylalanine and separation mechanism have been proposed. The limits of detection for phenylalanine and tyrosine were found to be 0.25 and 0.23 μg respectively. The proposed method studied is simple, rapid and free from the use of volatile organic solvents. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9805 [article]

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Thermodynamics of micellization and conductance behavior of uranyl soap solutions / V. Sharma in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 254-257 Titre : Thermodynamics of micellization and conductance behavior of uranyl soap solutions Type de document : texte imprimé Auteurs : V. Sharma, Auteur ; M. Sharma, Auteur ; D. Gautam, Auteur Année de publication : 2010 Article en page(s) : p. 254-257 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Micelles Savon Surfactants Tags : Savon  'Concentration  micellaire  critique'  Conductivité  Dissociation  Association Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The conductance results showed that uranyl soaps behave as weak electrolyte in dilute solution of N,N-dimethylformamide (DMF) at various temperatures below the critical micelle concentration, indicating that Debye–Hückel–Onsager's equation is not applicable to these soaps solutions. The value of critical micelle concentration decreases with increasing chain length of the soap and increasing temperature. The results were used to evaluate various thermodynamic parameters for both dissociation and association processes and may be satisfactorily explained in the light of phase separation model. The results show that the dissociation process of these soaps was found to be endothermic while micellization is exothermic in nature. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9806 [article]

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The micelle-to-vesicle phase transition in dilute aqueous solution from undecylamine induced by metal(II) ion (Cu2+) / G. Wang in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 47, N° 4/2010 (07-08/2010)

[article]  inTENSIDE, SURFACTANTS, DETERGENTS > Vol. 47, N° 4/2010 (07-08/2010) . - p. 258-261 Titre : The micelle-to-vesicle phase transition in dilute aqueous solution from undecylamine induced by metal(II) ion (Cu2+) Type de document : texte imprimé Auteurs : G. Wang, Auteur ; G. Li, Auteur Année de publication : 2010 Article en page(s) : p. 258-261 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants Tags : Surfactant  'Phase  de  vésicule'  'Double  couche  moléculaire'  'Dispersion  la  lumière'  'Microscopie  électronique  à  transmission'  TEM Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : A metal(II) ion (Cu2+)-induced vesicle phase was prepared from a mixture of n-undecylamine and CuCl2 in aqueous solution. Cu2+-ligand coordination with n-undecylamine results in the formation of molecular bilayers because Cu2+ can firmly bind to the amine groups of n-undecylamine which reduced the area of the head-group. In this system, no counterions in aqueous solution exist because of the Cu2+-ligand coordination, and the bilayer membranes are not shielded by salts. The vesicles were determined by transmission electron microscopy (TEM) images and dynamic light scattering (DLS) measurements. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9807 [article]

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