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Urszula Domanska - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic study of molecular interaction selectivity in separation processes based on limiting activity coefficients
The Journal of Chemical Thermodynamics, 2018Co-Authors: Urszula Domanska, Monika Karpinska, Michal WlazloAbstract:Abstract The effect of interactions between organic solvents and water on the interfacial and bulk properties of N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA] were discussed on the base of the limiting activity coefficients γ 13 ∞ values. The experimental γ 13 ∞ values were determined by gas–liquid chromatography at temperatures from (298.15 to 368.15) K for 61 assorted solutes—among them, alkanes (linear, branched, or cyclic), alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, tetrahydrofuran, 1,4-dioxane, ethers, acetone, ketones, acetonitrile, pyridine, and 1-Nitropropane. The partial molar excess Gibbs free energy Δ G 1 E, ∞ , the partial molar excess enthalpy Δ H 1 E, ∞ , and entropy at reference temperature T ref Δ S 1 E, ∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over this temperature range. The gas–liquid partition coefficient K L was calculated for each solute and discussed in light of the Abraham solvation parameter model. The density and viscosity of the [EMMor][DCA] as a function of temperature were also measured. The selectivity and capacity for six separation problems were calculated from γ 13 ∞ and compared to literature values for selected ionic liquids. These separation problems are central to the petroleum and organic chemistry industry. The data presented here shows that [EMMor][DCA] reveals large selectivity equal 140, 273, 538, 73.1, 87.5 and 10.2 in heptane/benzene, heptane/thiophene, heptane/ethanol, hexane/ethyl acetate, ethyl-tert-butyl ether, ETBE/ethanol and THF/water separation problems at T = 328.15 K. The capacities were 0.22, 0.42, 0.83, 0.17 and 2.97 for benzene, thiophene, ethanol, ethyl acetate, and water at the same temperature.
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thermodynamics and selectivity of separation based on activity coefficients at infinite dilution of various solutes in 1 allyl 3 methylimidazolium bis trifluoromethyl sulfonyl imide ionic liquid
The Journal of Chemical Thermodynamics, 2016Co-Authors: Michal Wlazlo, Urszula Domanska, Monika KarpinskaAbstract:Abstract The effect of interaction between organic solvents or water on the interfacial and bulk properties of 1-allyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide ([AMIM][NTf2]) and on activity coefficients ( γ 13 ∞ ) at infinite dilution for 64 solutes. The observations monitored by gas-liquid chromatography at six temperatures in range of (318.15–368.15) K are explained for polar and non-polar solutes as alkanes, alkenes and alkynes as well as aromatic hydrocarbons, alcohols, water, ethers, ketones, acetonitrile, pyridine, 1-Nitropropane, thiophene, and esters. Density, ρ and viscosity η as a function of temperature, T for chosen ionic liquid, [AMIM][NTf2] at pressure p = 101 kPa were measured. The gas-liquid partition coefficients, K L at infinite dilution and the fundamental thermodynamic functions, the partial molar excess Gibbs energy, enthalpy and entropy at infinite dilution were calculated. The values of selectivity and capacity for three separation problems as hexane/hex-1-ene, cyclohexane/cyclohexene and ethylbenzene/styrene were calculated from γ 13 ∞ and compared to literature values for imidazolium-based or bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids (ILs) for the same separation problems. The data presented here show that [AMIM][NTf2] reveals average selectivity in the comparison to measured earlier ILs in the chosen separation problems. These findings seem useful for future applications of ILs especially for alkanes/alkenes separation process.
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activity coefficients at infinite dilution of organic solvents and water in 1 butyl 3 methylimidazolium dicyanamide a literature review of hexane hex 1 ene separation
Fluid Phase Equilibria, 2016Co-Authors: Michal Wlazlo, Urszula Domanska, Monika KarpińskaAbstract:Abstract The work presented focused on the experimental data of the activity coefficients at infinite dilution, ( γ 13 ∞ ) of several solutes in ionic liquid of 1-butyl-3-methylimidazolium dicyanamide, [BMIM][DCA]. The values of γ 13 ∞ for 64 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, ethers, ketones, acetonitrile, pyridine, 1-Nitropropane, thiophene, and esters in [BMIM][DCA] were determined by gas–liquid chromatography at six temperatures in range of (318.15–368.15) K. The gas–liquid partition coefficients were calculated for all solutes. The partial molar excess Gibbs energy, enthalpy and entropy at infinite dilution were calculated from the experimental γ 13 ∞ values. The [BMIM][DCA] was discussed as a solvent for the different types of separation problems with special attention to the separation of hexane/hex-1-ene, cyclohexane/cyclohexene and ethylbenzene/styrene. This work discuss a particular type of mixture made up of small hydrocarbons (alkanes) and their unsaturated counterparts (alkenes). The separating ability of the investigated ionic liquid was compared with the previously investigated 1-butyl-3-methylimidazolium-based, and dicyanoamide-based ILs for three chosen separation problems. Additionally, a literature review of γ 13 ∞ for the hexane/hex-1-ene separation problem at T = 323.15 K is presented for the years 2010–2015. It was found that several ILs may replace conventional solvents. The proposed [BMIM][DCA] may be used as an alternative solvent for the separation of alkenes from alkanes.
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measurements of activity coefficients at infinite dilution of organic solutes and water on polar imidazolium based ionic liquids
The Journal of Chemical Thermodynamics, 2015Co-Authors: Joao A P Coutinho, Monia A R Martins, Simao P Pinho, Urszula DomanskaAbstract:Abstract The activity coefficients at infinite dilution, γ 13 ∞ , of 55 organic solutes and water in three ionic liquids with the common cation 1-butyl-3-methylimidazolium and the polar anions Cl−, [CH3SO3]− and [(CH3)2PO4]−, were determined by (gas + liquid) chromatography at four temperatures in the range (358.15 to 388.15) K for alcohols and water, and T = (398.15 to 428.15) K for the other organic solutes including alkanes, cycloalkanes, alkenes, cycloalkenes, alkynes, ketones, ethers, cyclic ethers, aromatic hydrocarbons, esters, butyraldehyde, acetonitrile, pyridine, 1-Nitropropane and thiophene. From the experimental γ 13 ∞ values, the partial molar excess Gibbs free energy, G ‾ m E , ∞ , enthalpy H ‾ m E , ∞ , and entropy S ‾ m E , ∞ , at infinite dilution, were estimated in order to provide more information about the interactions between the solutes and the ILs. Moreover, densities were measured and (gas + liquid) partition coefficients ( K L ) calculated. Selectivities at infinite dilution for some separation problems such as octane/benzene, cyclohexane/benzene and cyclohexane/thiophene were calculated using the measured γ 13 ∞ , and compared with literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, and other ionic liquids with a common cation or anion of the ILs here studied. From the obtained infinite dilution selectivities and capacities, it can be concluded that the ILs studied may replace conventional entrainers applied for the separation processes of aliphatic/aromatic hydrocarbons.
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activity coefficients at infinite dilution for organic solutes and water in 1 ethyl 1 methylpyrrolidinium lactate
The Journal of Chemical Thermodynamics, 2015Co-Authors: Urszula Domanska, Monika Karpinska, Maciej ZawadzkiAbstract:Abstract Synthesis of new ionic liquid 1-ethyl-1-methylpyrrolidinium lactate (racemate), [EMPYR][Lac] was performed. The characterization of the new compound by NMR spectra, elementary analysis, water content, and TG/DTA is presented. The activity coefficients at infinite dilution, γ 13 ∞ , for 54 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, ethers, ketones, acetonitrile, pyridine, 1-Nitropropane, thiophene, and esters in the [EMPYR][Lac] were determined by gas–liquid chromatography for most of the solutes at eight temperatures within the range of (308.15 to 378.15) K and for alcohols and water at higher temperatures in a range of (358.15 to 408.15) K. The partial molar excess Gibbs energy, Δ G 1 E, ∞ , enthalpy Δ H 1 E, ∞ , and entropy term T ref Δ S 1 E, ∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The values of selectivity for few separation problems as hexane/hex-1-ene, cyclohexane/cyclohexene and hexane/benzene were calculated from γ 13 ∞ and compared to literature values for pyrrolidinium-based ionic liquids (ILs) on the same separation problems. In comparison with the former measured ILs, the [EMPYR][Lac] presents quite high selectivity for the separation of alkenes from aliphatic hydrocarbons, an average capacity for alkenes. The data presented here shows that [EMPYR][Lac] may be proposed as an alternative solvent for the separation of alkenes from the aliphatic hydrocarbons.
Michal Wlazlo - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic study of molecular interaction selectivity in separation processes based on limiting activity coefficients
The Journal of Chemical Thermodynamics, 2018Co-Authors: Urszula Domanska, Monika Karpinska, Michal WlazloAbstract:Abstract The effect of interactions between organic solvents and water on the interfacial and bulk properties of N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA] were discussed on the base of the limiting activity coefficients γ 13 ∞ values. The experimental γ 13 ∞ values were determined by gas–liquid chromatography at temperatures from (298.15 to 368.15) K for 61 assorted solutes—among them, alkanes (linear, branched, or cyclic), alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, tetrahydrofuran, 1,4-dioxane, ethers, acetone, ketones, acetonitrile, pyridine, and 1-Nitropropane. The partial molar excess Gibbs free energy Δ G 1 E, ∞ , the partial molar excess enthalpy Δ H 1 E, ∞ , and entropy at reference temperature T ref Δ S 1 E, ∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over this temperature range. The gas–liquid partition coefficient K L was calculated for each solute and discussed in light of the Abraham solvation parameter model. The density and viscosity of the [EMMor][DCA] as a function of temperature were also measured. The selectivity and capacity for six separation problems were calculated from γ 13 ∞ and compared to literature values for selected ionic liquids. These separation problems are central to the petroleum and organic chemistry industry. The data presented here shows that [EMMor][DCA] reveals large selectivity equal 140, 273, 538, 73.1, 87.5 and 10.2 in heptane/benzene, heptane/thiophene, heptane/ethanol, hexane/ethyl acetate, ethyl-tert-butyl ether, ETBE/ethanol and THF/water separation problems at T = 328.15 K. The capacities were 0.22, 0.42, 0.83, 0.17 and 2.97 for benzene, thiophene, ethanol, ethyl acetate, and water at the same temperature.
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thermodynamics and selectivity of separation based on activity coefficients at infinite dilution of various solutes in 1 allyl 3 methylimidazolium bis trifluoromethyl sulfonyl imide ionic liquid
The Journal of Chemical Thermodynamics, 2016Co-Authors: Michal Wlazlo, Urszula Domanska, Monika KarpinskaAbstract:Abstract The effect of interaction between organic solvents or water on the interfacial and bulk properties of 1-allyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide ([AMIM][NTf2]) and on activity coefficients ( γ 13 ∞ ) at infinite dilution for 64 solutes. The observations monitored by gas-liquid chromatography at six temperatures in range of (318.15–368.15) K are explained for polar and non-polar solutes as alkanes, alkenes and alkynes as well as aromatic hydrocarbons, alcohols, water, ethers, ketones, acetonitrile, pyridine, 1-Nitropropane, thiophene, and esters. Density, ρ and viscosity η as a function of temperature, T for chosen ionic liquid, [AMIM][NTf2] at pressure p = 101 kPa were measured. The gas-liquid partition coefficients, K L at infinite dilution and the fundamental thermodynamic functions, the partial molar excess Gibbs energy, enthalpy and entropy at infinite dilution were calculated. The values of selectivity and capacity for three separation problems as hexane/hex-1-ene, cyclohexane/cyclohexene and ethylbenzene/styrene were calculated from γ 13 ∞ and compared to literature values for imidazolium-based or bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids (ILs) for the same separation problems. The data presented here show that [AMIM][NTf2] reveals average selectivity in the comparison to measured earlier ILs in the chosen separation problems. These findings seem useful for future applications of ILs especially for alkanes/alkenes separation process.
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activity coefficients at infinite dilution of organic solvents and water in 1 butyl 3 methylimidazolium dicyanamide a literature review of hexane hex 1 ene separation
Fluid Phase Equilibria, 2016Co-Authors: Michal Wlazlo, Urszula Domanska, Monika KarpińskaAbstract:Abstract The work presented focused on the experimental data of the activity coefficients at infinite dilution, ( γ 13 ∞ ) of several solutes in ionic liquid of 1-butyl-3-methylimidazolium dicyanamide, [BMIM][DCA]. The values of γ 13 ∞ for 64 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, ethers, ketones, acetonitrile, pyridine, 1-Nitropropane, thiophene, and esters in [BMIM][DCA] were determined by gas–liquid chromatography at six temperatures in range of (318.15–368.15) K. The gas–liquid partition coefficients were calculated for all solutes. The partial molar excess Gibbs energy, enthalpy and entropy at infinite dilution were calculated from the experimental γ 13 ∞ values. The [BMIM][DCA] was discussed as a solvent for the different types of separation problems with special attention to the separation of hexane/hex-1-ene, cyclohexane/cyclohexene and ethylbenzene/styrene. This work discuss a particular type of mixture made up of small hydrocarbons (alkanes) and their unsaturated counterparts (alkenes). The separating ability of the investigated ionic liquid was compared with the previously investigated 1-butyl-3-methylimidazolium-based, and dicyanoamide-based ILs for three chosen separation problems. Additionally, a literature review of γ 13 ∞ for the hexane/hex-1-ene separation problem at T = 323.15 K is presented for the years 2010–2015. It was found that several ILs may replace conventional solvents. The proposed [BMIM][DCA] may be used as an alternative solvent for the separation of alkenes from alkanes.
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activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1 2 methoxyethyl 1 methylpyrrolidinium trifluorotris perfluoroethyl phosphate
The Journal of Chemical Thermodynamics, 2013Co-Authors: Andrzej Marciniak, Michal WlazloAbstract:Abstract This work presents new data of activity coefficients at infinite dilution, γ∞ of different organic solutes and water in the 1-(2-methoxyethyl)-1-methylpyrrolidinium trifluorotris(perfluoroethyl)phosphate ionic liquid. Values of γ∞ were determined for 62 solutes, including alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, 1-Nitropropane, butanal, acetonitrile and water by inverse gas chromatography over the temperature range from (318.15 to 368.15) K. The basic thermodynamic functions, namely partial molar excess Gibbs energies, Δ G 1 E, ∞ , enthalpies, Δ H 1 E, ∞ and entropies, Δ S 1 E, ∞ at infinite dilution were calculated from the experimental γ∞ values obtained over the temperature range. Additionally the gas–liquid partition coefficients, KL were determined. Experimental values of gas–liquid partition coefficients were used to determine the coefficients in the Abraham solvation parameter model (LFER). Results are compared to previously investigated ionic liquids with the same cations or anions. The selectivities and capacities at infinite dilution for alkanes/thiophene extraction problems were calculated from experimental γ∞ values to verify the possibility of investigated ionic liquid as an entrainer in liquid–liquid extraction.
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measurements of activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1 hexyl 3 methylimidazolium tetracyanoborate
The Journal of Chemical Thermodynamics, 2012Co-Authors: Elena Vadimovna Lukoshko, Urszula Domanska, Michal WlazloAbstract:Abstract The activity coefficients at infinite dilution, γ 13 ∞ , for 43 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, acetonitrile, pyridine, and 1-Nitropropane in the ionic liquid 1-ethyl-3-methylimidazolium methanesulfonate [EMIM][MeSO3] were determined by gas–liquid chromatography at six temperatures within the range (308.15 to 358.15) K. The interaction of these 42 organic compounds and water with the ionic liquid were described with the partial molar excess Gibbs free energy, Δ G 1 E, ∞ , enthalpy Δ H 1 E, ∞ , and entropy T ref Δ S 1 E, ∞ at infinite dilution, calculated from the experimental γ 13 ∞ values obtained over the temperature range. The gas–liquid partition coefficients, KL were calculated for all solutes. The values of the selectivity for few separation problems as heptane/toluene, cyclohexane/benzene, heptane/xylenes and heptane/thiophene were calculated from γ 13 ∞ and compared to literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, and other ionic liquids based on [EMIM]+ cation. Comparison with the results published earlier for [EMIM][MeSO3] show much lower selectivities in the discussed separation problems. By contrast with the former measured ILs [EMIM][MeSO3] reveals the average selectivity for the separation of aromatics/aliphatics and low capacity for benzene. An interesting high value of selectivity was observed in the separation of thiophene/aliphatics. Very high values of selectivity may be expected in the separation of the azeotropic systems including water. The density of [EMIM][MeSO3] within temperature range from (298.15 to 358.15) K was measured and compared to the literature values.
Elena Vadimovna Lukoshko - One of the best experts on this subject based on the ideXlab platform.
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thermodynamics and activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1 butyl 1 methylmorpholinium tricyanomethanide
The Journal of Chemical Thermodynamics, 2014Co-Authors: Urszula Domanska, Elena Vadimovna LukoshkoAbstract:Abstract The activity coefficients at infinite dilution, γ 13 ∞ , for 61 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, esters, aldehyde, acetonitrile, pyridine and 1-Nitropropane in the ionic liquid (IL) 1-butyl-1-methylmorpholinium tricyanomethanide, [BMMOR][TCM] were determined by gas–liquid chromatography at six temperatures within the range of (318.15 to 368.15) K. The thermodynamic functions at infinite dilution as partial molar excess Gibbs free energy Δ G 1 E, ∞ , enthalpy Δ H 1 E, ∞ , and entropy term T ref Δ S 1 E, ∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The density of [BMMOR][TCM] was measured over the temperature range (288.15 to 368.15) K. The gas–liquid partition coefficient KL was calculated for all solutes. The values of selectivity and capacity for a few separation problems such as hexane/benzene, cyclohexane/benzene, heptane/thiophene at T = 328.15 K were calculated from γ 13 ∞ and compared to literature values for similar ionic liquids, viz. N-methyl-2-pyrrolidinone (NMP), and sulfolane. In comparison with the previously measured values for [BMPYR][TCM], the morpholinium IL presents high selectivity for the separation of aromatic hydrocarbons from aliphatic hydrocarbons, and especially thiophene, or piridine from heptane with a slightly lower capacity. New data show that [BMMOR][TCM] IL may be proposed as an alternative solvent for the separation of sulphur or nitrogen compounds from alkanes.
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measurements of activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1 butyl 1 methylpyrrolidinium tricyanomethanide
The Journal of Chemical Thermodynamics, 2013Co-Authors: Urszula Domanska, Elena Vadimovna LukoshkoAbstract:The activity coefficients at infinite dilution, γ 13 ∞ , for 62 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, acetonitrile, pyridine and 1-Nitropropane in the ionic liquid 1-butyl-1-methylpyrrolidinium tricyanomethanide, [BMPYR][TCM] were determined by gas–liquid chromatography at six temperatures over the range of (318.15 to 368.15) K. The partial molar excess Gibbs free energy, Δ G 1 E ∞ , enthalpy Δ H 1 E ∞ , and entropy term T ref Δ S 1 E , ∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The densities of [BMPYR][TCM] were measured within temperature range from 318.15 K to 368.15 K. The gas–liquid partition coefficients, K L K L were calculated for all solutes. The values of selectivity for few separation problems as hexane/benzene, cyclohexane/benzene, heptane/thiophene were calculated from γ 13 ∞ and compared to literature values for N -methyl-2-pyrrolidinone (NMP), sulfolane, and other ionic liquids based on [BMPYR] + cation. In comparison with the former measured ILs, [BMPYR][TCM] present quite high selectivity for the separation of aromatic hydrocarbons and aliphatics hydrocarbons, an average capacity for benzene. The data presented here shows that [BMPYR][TCM] ionic liquid can be used as an alternative solvent for the separation of thiophene from the aliphatic hydrocarbons.
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measurements of activity coefficients at infinite dilution for organic solutes and water in the ionic liquid 1 hexyl 3 methylimidazolium tetracyanoborate
The Journal of Chemical Thermodynamics, 2012Co-Authors: Elena Vadimovna Lukoshko, Urszula Domanska, Michal WlazloAbstract:Abstract The activity coefficients at infinite dilution, γ 13 ∞ , for 43 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, acetonitrile, pyridine, and 1-Nitropropane in the ionic liquid 1-ethyl-3-methylimidazolium methanesulfonate [EMIM][MeSO3] were determined by gas–liquid chromatography at six temperatures within the range (308.15 to 358.15) K. The interaction of these 42 organic compounds and water with the ionic liquid were described with the partial molar excess Gibbs free energy, Δ G 1 E, ∞ , enthalpy Δ H 1 E, ∞ , and entropy T ref Δ S 1 E, ∞ at infinite dilution, calculated from the experimental γ 13 ∞ values obtained over the temperature range. The gas–liquid partition coefficients, KL were calculated for all solutes. The values of the selectivity for few separation problems as heptane/toluene, cyclohexane/benzene, heptane/xylenes and heptane/thiophene were calculated from γ 13 ∞ and compared to literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, and other ionic liquids based on [EMIM]+ cation. Comparison with the results published earlier for [EMIM][MeSO3] show much lower selectivities in the discussed separation problems. By contrast with the former measured ILs [EMIM][MeSO3] reveals the average selectivity for the separation of aromatics/aliphatics and low capacity for benzene. An interesting high value of selectivity was observed in the separation of thiophene/aliphatics. Very high values of selectivity may be expected in the separation of the azeotropic systems including water. The density of [EMIM][MeSO3] within temperature range from (298.15 to 358.15) K was measured and compared to the literature values.
Cihangir Tanyeli - One of the best experts on this subject based on the ideXlab platform.
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enantioselective michael addition of nitroalkanes to nitroalkenes catalyzed by chiral bifunctional quinine based squaramides
ChemInform, 2016Co-Authors: Esra Kanberoglu, Cihangir TanyeliAbstract:The reaction between (E)-β-nitrostyrenes and 1-Nitropropane proceeds with moderate to very high yields, high dia- and very high enantioselectivities.
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enantioselective michael addition of nitroalkanes to nitroalkenes catalyzed by chiral bifunctional quinine based squaramides
Asian Journal of Organic Chemistry, 2016Co-Authors: Esra Kanberoglu, Cihangir TanyeliAbstract:A family of chiral bifunctional acid-/base-type quinine/squaramide organocatalysts is shown to be highly active promoters of the conjugate addition of 1-Nitropropane to various trans-β-nitroalkenes. The cooperation of the quinine and the sterically encumbered squaramide moieties catalyzed the Michael addition reactions at 0 °C by using a catalyst loading of only 2 mol % to afford the 1,3-dinitro Michael adducts with excellent enantioselectivity and diastereoselectivity (up to 95 % ee and syn/anti isomers up to 96:4).
Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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development and validation of an improved thin film solid phase microextraction based standard gas generating vial for the repeatable generation of gaseous standards
Journal of Chromatography A, 2020Co-Authors: Jonathan J Grandy, Khaled Murtada, Joao Raul Belinato, Paola Alejandra Ortiz Suarez, Janusz PawliszynAbstract:Abstract This work presents the development and validation of novel thin film solid phase micro extraction (TF-SPME) based standard gas generating vials suitable for repeatable generation of gaseous standards for GC–MS analysis and quality control. The vials were developed using carbon mesh membranes loaded with pure polydimethylsiloxane (PDMS), divinylbenzene (DVB/PDMS), hydrophilic-lipophilic balance (HLB/PDMS), and carboxen (Car/PDMS) sorbents that were then spiked with modified McReynolds standards including benzene, 2-pentanone, 1-Nitropropane, pyridine, 1-pentanol, octane, dodecane, and hexadecane. Sorbent strength was determined to follow the aforementioned order, with pure PDMS presenting the weakest sorption capabilities and Car/PDMS the strongest. While the weaker, pure PDMS based gas generating vials transferred an instrument-overloading amount of McReynolds probes to the 1.1 mm DVB/PDMS SPME arrows used for extraction, vials prepared using Car/PDMS TF-SPME as a sorbent failed to provide consistently detectable amounts of analytes less volatile than 1-Nitropropane. The DVB/PDMS and HLB/PDMS based vials were found to maintain optimal sorption capabilities for the tested analytes, providing a sorption strength strong enough to not exhibit any depletion in 10 replicate runs, while still delivering a consistent amount of all the regular McReynolds components. Moreover, with intra-vial%RSDs of 5% or less for all analytes tested, these HLB and DVB vials were found to deliver very good repeatability. After purposely submitting vials to 200 accelerated depletion extractions (1.1 mm DVB/PDMS arrow at 55 °C for 3 min), vials prepared with DVB/PDMS were found to deplete by 33%, 38%, 34%, 33%, 40%, and 33% while vials prepared with HLB/PDMS were found to deplete by 21%, 16%, 12%, 31%, 16% and 0% for benzene, 2-pentanone, 1-Nitropropane, pyridine, 1-pentanol, and octane, respectively. When user typical extractions conditions were used instead (50/30 μm DVB/Car/PDMS SPME fiber at 35 °C for 1 min), no depletion could be observed from the HLB/PDMS based vial while%RSDs ranged from 1.1–3.0% after the 300 extraction/desorption cycles. Finally, in efforts to demonstrate its real world applicability, the DVB/PDMS vial was used to evaluate the inter-fiber repeatability of commercial DVB/PDMS SPME arrows, with results demonstrating that arrows from a single package were statistically similar (ANOVA at 95% confidence).
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Development of a Hydrophilic Lipophilic Balanced Thin Film Solid Phase Microextraction Device for Balanced Determination of Volatile Organic Compounds
2018Co-Authors: Jonathan J. Grandy, Varoon Singh, Maryam Lashgari, Mario Gauthier, Janusz PawliszynAbstract:A novel hydrophilic–lipophilic balanced (HLB) thin film solid-phase microextraction (TF-SPME) device is proposed for polarity-balanced determinations of volatile organic compounds. The proposed HLB particles used in the preparation of these membranes were prepared using a precipitation polymerization technique and determined to have a specific surface area of 335 m2/g with an average pore diameter of 13 Å. Membranes prepared from these particles were found to extract 1.8, 2.2, 1.9, 1.7, 2.0, and 1.3 times more benzene, 2-pentanone, 1-Nitropropane, pyridine, 1-pentanol, and octane, respectively, than the established divinylbenzene/polydimethylsiloxane (DVB/PDMS)-based membranes. Furthermore, membranes prepared from these lab-made particles were shown to extract significantly (p = 0.00047) larger amounts of these analytes than membranes prepared from comparative commercial HLB particles. The intermembrane extraction efficiency between 3 membranes was determined to be reproducible at 95% confidence for 4 different coating chemistries tested, including the DVB/PDMS membranes, and those prepared with 3 different HLB compositions. Furthermore, method reliability was established by confirming that, once extracted, modified McReynolds standards were stable on the HLB/PDMS membranes stored in thermal desorption tubes on an autosampler rack for at least 120 h, for 5 of the 6 standards, but only for 24 h for pyridine at a 95% level of confidence. Finally, using a TF-SPME enabled, portable GC/MS instrument, an entirely on-site proof of concept application was performed for the determination and quantitation of chlorination byproducts in a private hot tub, successfully identifying chloroform, bromodichloromethane, dichloroacetonitrile, chlorobenzene, benzonitrile, and benzyl chloride, while further quantifying chloroform and dichloroacetonitrile at levels of 270 and 79 ppb with %RSD values of 13% and 5%, respectively
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development of a new in vial standard gas system for calibrating solid phase microextraction in high throughput and on site applications
IEEE Journal of Solid-state Circuits, 2013Co-Authors: German Augusto Gomezrios, Nathaly Reyesgarces, Janusz PawliszynAbstract:In this work, an innovative, reproducible, and reusable standard generator vial is presented. The standard generator vial consists of vacuum-pump oil doped with McReynolds probes (benzene, 2-pentanone, pyridine, nitropropane, 1-pentanol, and n-octane) mixed with a polystyrene-divinylbenzene resin without functional groups. The evaluation of this vial was fully automated on a multifiber exchanger system and the extraction/desorption cycle, together with the programmed GC–qMS analysis, did not exceed 13 min. The results showed that after 160 extraction/injections cycles of the vial the relative SDs were smaller than 4% for all the standards. A randomized block design was used to evaluate the inter and intravial repeatability, and at 95% level of confidence nonstatistical differences among vials were found. Because of its compacted granular appearance this vial is easy to transport, and it is an ideal calibration standard for bench and field instruments and devices.
