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Evaluation of group-contribution methods to predict VLE and odor intensity of fragrances / Miguel A. Teixeira in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9390-9402 Titre : Evaluation of group-contribution methods to predict VLE and odor intensity of fragrances Type de document : texte imprimé Auteurs : Miguel A. Teixeira, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur Année de publication : 2011 Article en page(s) : pp. 9390-9402 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Odor  Group  contribution  method Résumé : Several predictive GE methods based on the group-contribution concept have been tested for prediction of multicomponent vapor-liquid equilibria (VLE) of fragrance mixtures. The evaluation covered 24 binary, 20 ternary, and 21 quaternary mixtures combining six different fragrances typically used in perfume formulation and ethanol as the solvent. The selected predictive methods are the original UNIFAC (updated to the last revision), the UNIFAC-Dortmund, the ASOG, and the A-UNIFAC. The equilibrium compositions were experimentally measured at 23 °C by headspace gas chromatography (HS-GC). For each liquid composition, the corresponding experimental and predicted vapor compositions were compared. This study confirmed that the UNIFAC method is the best predictive model for prediction of VLE, while the A-UNIFAC performed poorer than other evaluated methods for the mixtures studied in this work. Moreover, from the vapor composition the odor intensity and character of the fragrance mixtures was calculated using a previous developed model which considers the Stevens' power law for the olfaction intensity scale and the stronger component model for quality perception. In this way, the odor intensity and character of fragrance mixtures was predicted and compared to experimental and sensorial evaluations. From this work it can be concluded that the UNIFAC and UNIFAC-Dortmund methods allow obtaining optimal predictions of the character of the fragrance mixtures with an agreement of 95.4% when compared to experimental measurements. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395884 [article] Evaluation of group-contribution methods to predict VLE and odor intensity of fragrances [texte imprimé] / Miguel A. Teixeira, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur . - 2011 . - pp. 9390-9402. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9390-9402 Mots-clés : Odor  Group  contribution  method Résumé : Several predictive GE methods based on the group-contribution concept have been tested for prediction of multicomponent vapor-liquid equilibria (VLE) of fragrance mixtures. The evaluation covered 24 binary, 20 ternary, and 21 quaternary mixtures combining six different fragrances typically used in perfume formulation and ethanol as the solvent. The selected predictive methods are the original UNIFAC (updated to the last revision), the UNIFAC-Dortmund, the ASOG, and the A-UNIFAC. The equilibrium compositions were experimentally measured at 23 °C by headspace gas chromatography (HS-GC). For each liquid composition, the corresponding experimental and predicted vapor compositions were compared. This study confirmed that the UNIFAC method is the best predictive model for prediction of VLE, while the A-UNIFAC performed poorer than other evaluated methods for the mixtures studied in this work. Moreover, from the vapor composition the odor intensity and character of the fragrance mixtures was calculated using a previous developed model which considers the Stevens' power law for the olfaction intensity scale and the stronger component model for quality perception. In this way, the odor intensity and character of fragrance mixtures was predicted and compared to experimental and sensorial evaluations. From this work it can be concluded that the UNIFAC and UNIFAC-Dortmund methods allow obtaining optimal predictions of the character of the fragrance mixtures with an agreement of 95.4% when compared to experimental measurements. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395884

Free energy of transfer of a methylene group in biphasic systems of water and ionic liquids [C3mpip] [NTf2], [C3mpyrr] [NTf2], and [C4mpyrr] [NTf2] / Filipa M. Maia in Industrial & engineering chemistry research, Vol. 51 N° 23 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 8061-8068 Titre : Free energy of transfer of a methylene group in biphasic systems of water and ionic liquids [C3mpip] [NTf2], [C3mpyrr] [NTf2], and [C4mpyrr] [NTf2] Type de document : texte imprimé Auteurs : Filipa M. Maia, Auteur ; Oscar Rodriguez, Auteur ; Eugénia A. Macedo, Auteur Année de publication : 2012 Article en page(s) : pp. 8061-8068 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic  properties  Ionic  liquid  Biphasic  system  Free  energy Résumé : Three hydrophobic ionic liquids (ILs) based on the bis(txifluoromethylsulfonyl)imide anion were studied in terms of the relative hydrophobicity of the equilibrium phases. The ILs were 1-methyl-1-propylpiperidinium bis-(trifluoromethylsulfonyl)imide, [C3mpip][NTf2]; 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide, (C3mpyrr]-[NTf2j; and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr](NTf2]. In addition, the liquid-liquid phase diagrams were determined for two of the ILs, namely, [C3mpip][NTf2] and [C3mpyrr][NTf2]. The compositions of the equilibrium phases were obtained using a gravimetric technique in the temperature range from 278.15 to 343.15 K. The immiscibility gaps for these systems were found to be very large, with that for the system [C3mpip][NTf2] + water being slightly wider than that for the system [C3mpyrr][NTf2] + water. Partition coefficients for a series of dinitrophenylated (DNP) amino acids in the three systems at 296.15 K were experimentally determined. The DNP amino acids were found to distribute preferentially to the water-rich phase, and the partition was more extreme for the system with [C3mpip][NTf2]. The experimental partition coefficients decreased as the size of the alkyl side chain in the solutes increased. The relative hydrophobicity of the equilibrium phases was assessed by means of the free energy of transfer of a methylene group between the phases, ΔG(CH2), calculated from the partition coefficients of the series of solutes. It was found that the relative hydrophobicity between the phases follows the order [C4mpyrr][NTf2] > [C3mpip][NTf2] > [C3mpyrr][NTf2]. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990318 [article] Free energy of transfer of a methylene group in biphasic systems of water and ionic liquids [C3mpip] [NTf2], [C3mpyrr] [NTf2], and [C4mpyrr] [NTf2] [texte imprimé] / Filipa M. Maia, Auteur ; Oscar Rodriguez, Auteur ; Eugénia A. Macedo, Auteur . - 2012 . - pp. 8061-8068. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 8061-8068 Mots-clés : Thermodynamic  properties  Ionic  liquid  Biphasic  system  Free  energy Résumé : Three hydrophobic ionic liquids (ILs) based on the bis(txifluoromethylsulfonyl)imide anion were studied in terms of the relative hydrophobicity of the equilibrium phases. The ILs were 1-methyl-1-propylpiperidinium bis-(trifluoromethylsulfonyl)imide, [C3mpip][NTf2]; 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide, (C3mpyrr]-[NTf2j; and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr](NTf2]. In addition, the liquid-liquid phase diagrams were determined for two of the ILs, namely, [C3mpip][NTf2] and [C3mpyrr][NTf2]. The compositions of the equilibrium phases were obtained using a gravimetric technique in the temperature range from 278.15 to 343.15 K. The immiscibility gaps for these systems were found to be very large, with that for the system [C3mpip][NTf2] + water being slightly wider than that for the system [C3mpyrr][NTf2] + water. Partition coefficients for a series of dinitrophenylated (DNP) amino acids in the three systems at 296.15 K were experimentally determined. The DNP amino acids were found to distribute preferentially to the water-rich phase, and the partition was more extreme for the system with [C3mpip][NTf2]. The experimental partition coefficients decreased as the size of the alkyl side chain in the solutes increased. The relative hydrophobicity of the equilibrium phases was assessed by means of the free energy of transfer of a methylene group between the phases, ΔG(CH2), calculated from the partition coefficients of the series of solutes. It was found that the relative hydrophobicity between the phases follows the order [C4mpyrr][NTf2] > [C3mpip][NTf2] > [C3mpyrr][NTf2]. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990318

Gibbs free energy of transfer of a methylene group in buffer + ionic liquid biphasic systems / Oscar Rodriguez in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5165–5168 Titre : Gibbs free energy of transfer of a methylene group in buffer + ionic liquid biphasic systems Type de document : texte imprimé Auteurs : Oscar Rodriguez, Auteur ; Pedro P. Madeira, Auteur ; Eugénia A. Macedo, Auteur Année de publication : 2008 Article en page(s) : p. 5165–5168 Note générale : Bibliogr. p. 5168 Langues : Anglais (eng) Mots-clés : Dinitrophenylated  amino-acids;  Ionic  liquid  system Résumé : Partitioning experiments for a series of dinitrophenylated (DNP) amino-acids have been conducted in three (ionic liquid + sodium phosphate buffer) biphasic systems at 23 °C. The ionic liquids used were 1-hexyl-3-methylimidazolium tetrafluoroborate ([C6mim][BF4]), 1-octyl-3-methylimidazolium tetrafluoroborate ([C8mim][BF4]), and 1-decyl-3-methylimidazolium tetrafluoroborate ([C10mim][BF4]). The pH of the initial aqueous solution has been fixed at 7.4, using a sodium phosphate buffer. DNP−amino acids distribute preferentially to the ionic liquid phase, and this partition increases with the length of the alkyl chain of the amino acid. The Gibbs free energy of transfer for a methylene group is calculated from the partition coefficients of the solutes. This provides a measurement for the relative hydrophobicity of the conjugated phases, and the obtained values are compared to those of other biphasic systems used in biotechnology (e.g., polymer−polymer and polymer−salt aqueous two-phase systems). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0714293 [article] Gibbs free energy of transfer of a methylene group in buffer + ionic liquid biphasic systems [texte imprimé] / Oscar Rodriguez, Auteur ; Pedro P. Madeira, Auteur ; Eugénia A. Macedo, Auteur . - 2008 . - p. 5165–5168. Bibliogr. p. 5168 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5165–5168 Mots-clés : Dinitrophenylated  amino-acids;  Ionic  liquid  system Résumé : Partitioning experiments for a series of dinitrophenylated (DNP) amino-acids have been conducted in three (ionic liquid + sodium phosphate buffer) biphasic systems at 23 °C. The ionic liquids used were 1-hexyl-3-methylimidazolium tetrafluoroborate ([C6mim][BF4]), 1-octyl-3-methylimidazolium tetrafluoroborate ([C8mim][BF4]), and 1-decyl-3-methylimidazolium tetrafluoroborate ([C10mim][BF4]). The pH of the initial aqueous solution has been fixed at 7.4, using a sodium phosphate buffer. DNP−amino acids distribute preferentially to the ionic liquid phase, and this partition increases with the length of the alkyl chain of the amino acid. The Gibbs free energy of transfer for a methylene group is calculated from the partition coefficients of the solutes. This provides a measurement for the relative hydrophobicity of the conjugated phases, and the obtained values are compared to those of other biphasic systems used in biotechnology (e.g., polymer−polymer and polymer−salt aqueous two-phase systems). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0714293

Kinetic and stability study of the peroxidase inhibition in ionic liquids / Aristides P. Carneiro in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10810–10815 Titre : Kinetic and stability study of the peroxidase inhibition in ionic liquids Type de document : texte imprimé Auteurs : Aristides P. Carneiro, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur Année de publication : 2010 Article en page(s) : pp. 10810–10815 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetic--Stability--Peroxidase--Inhibition--Ionic--Liquids Résumé : The activity and stability of peroxidase in aqueous solutions of two ionic liquids (ILs) have been studied. The ILs selected were 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, [emim][MDEGSO4], and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4]. Experiments were performed at room temperature using concentrations of ILs between 5 and 50% (v/v) and pH values in the range from 5 to 9. The initial activity of the enzyme in these ILs at optimized conditions (pH 7 and 5−10% IL) was similar or higher than that achieved with buffer solution. Kinetic studies showed that maximum reaction velocity (Vmax) decreased with increasing concentration of IL. The effect of [emim][EtSO4] concentration on the decrease of Vmax was higher than that of [emim][MDEGSO4]. It was found that [emim][EtSO4] was a more potent inhibitor on peroxidase activity. The peroxidase studied was active in the ILs investigated, and the enzyme exhibited a higher stability in ILs at the optimized conditions. Kinetic studies showed that inhibition was a noncompetitive type in both ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007612 [article] Kinetic and stability study of the peroxidase inhibition in ionic liquids [texte imprimé] / Aristides P. Carneiro, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur . - 2010 . - pp. 10810–10815. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10810–10815 Mots-clés : Kinetic--Stability--Peroxidase--Inhibition--Ionic--Liquids Résumé : The activity and stability of peroxidase in aqueous solutions of two ionic liquids (ILs) have been studied. The ILs selected were 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, [emim][MDEGSO4], and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4]. Experiments were performed at room temperature using concentrations of ILs between 5 and 50% (v/v) and pH values in the range from 5 to 9. The initial activity of the enzyme in these ILs at optimized conditions (pH 7 and 5−10% IL) was similar or higher than that achieved with buffer solution. Kinetic studies showed that maximum reaction velocity (Vmax) decreased with increasing concentration of IL. The effect of [emim][EtSO4] concentration on the decrease of Vmax was higher than that of [emim][MDEGSO4]. It was found that [emim][EtSO4] was a more potent inhibitor on peroxidase activity. The peroxidase studied was active in the ILs investigated, and the enzyme exhibited a higher stability in ILs at the optimized conditions. Kinetic studies showed that inhibition was a noncompetitive type in both ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007612

Kinetic and stability study of the peroxidase inhibition in ionic liquids / Aristides P. Carneiro in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10810–10815 Titre : Kinetic and stability study of the peroxidase inhibition in ionic liquids Type de document : texte imprimé Auteurs : Aristides P. Carneiro, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur Année de publication : 2010 Article en page(s) : pp. 10810–10815 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ionic  liquids  Peroxidase  Kinetic  study  Stability  study Résumé : The activity and stability of peroxidase in aqueous solutions of two ionic liquids (ILs) have been studied. The ILs selected were 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, [emim][MDEGSO4], and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4]. Experiments were performed at room temperature using concentrations of ILs between 5 and 50% (v/v) and pH values in the range from 5 to 9. The initial activity of the enzyme in these ILs at optimized conditions (pH 7 and 5−10% IL) was similar or higher than that achieved with buffer solution. Kinetic studies showed that maximum reaction velocity (Vmax) decreased with increasing concentration of IL. The effect of [emim][EtSO4] concentration on the decrease of Vmax was higher than that of [emim][MDEGSO4]. It was found that [emim][EtSO4] was a more potent inhibitor on peroxidase activity. The peroxidase studied was active in the ILs investigated, and the enzyme exhibited a higher stability in ILs at the optimized conditions. Kinetic studies showed that inhibition was a noncompetitive type in both ILs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007612 [article] Kinetic and stability study of the peroxidase inhibition in ionic liquids [texte imprimé] / Aristides P. Carneiro, Auteur ; Oscar Rodriguez, Auteur ; Fatima L. Mota, Auteur . - 2010 . - pp. 10810–10815. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10810–10815 Mots-clés : Ionic  liquids  Peroxidase  Kinetic  study  Stability  study Résumé : The activity and stability of peroxidase in aqueous solutions of two ionic liquids (ILs) have been studied. The ILs selected were 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, [emim][MDEGSO4], and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4]. Experiments were performed at room temperature using concentrations of ILs between 5 and 50% (v/v) and pH values in the range from 5 to 9. The initial activity of the enzyme in these ILs at optimized conditions (pH 7 and 5−10% IL) was similar or higher than that achieved with buffer solution. Kinetic studies showed that maximum reaction velocity (Vmax) decreased with increasing concentration of IL. The effect of [emim][EtSO4] concentration on the decrease of Vmax was higher than that of [emim][MDEGSO4]. It was found that [emim][EtSO4] was a more potent inhibitor on peroxidase activity. The peroxidase studied was active in the ILs investigated, and the enzyme exhibited a higher stability in ILs at the optimized conditions. Kinetic studies showed that inhibition was a noncompetitive type in both ILs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007612

Perfumery Radar: / Miguel A. Teixeira in Industrial & engineering chemistry research, Vol. 49 N° 22 (Novembre 2010) 

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