Inverse Gas-liquid Chromatography Research Articles

The influence of the ionic liquids functionalization on interaction in binary systems with organic solutes and water – Thermodynamic data of activity coefficients at infinite dilution

In this work, the effect of IL’s functionalization of the interaction of IL with organic solutes and water at infinite dilution has been investigated. Based on the experimental activity coefficients at infinite dilution, (γ13∞) the possibility of using ionic liquids (ILs) in different separation processes, such as aliphatic from aromatic hydrocarbon (heptane/benzene, or cyclohexane/benzene), desulfurization and denitrification of model fuel (heptane/thiophene and heptane/pyridine) were investigated based on the experimental study of the activity coefficients at infinite dilution. The (γ13∞) values were determined for more than fifty different solutes including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, ethers, ketones, thiophene, acetonitrile, pyridine, 1-nitropropane and water in two ionic liquids: 4-(3-cyanopropyl)-4-methylmorpholinium tricyanomethanide, [Mo1,3CN][TCM] and 4-(3-hydroxypropyl)-4-methylmorpholinium tricyanomethanide, [Mo1,3OH][TCM]. The experiment was performed using inverse gas–liquid chromatography at a wide temperature range from T = (308.15 to 358.15) K. From the experimental data, the partial molar excess Gibbs energy (ΔG1E,∞), enthalpy (ΔH1E,∞) and entropy (Tref ΔS1E,∞) at infinite dilution were determined. The gas–liquid partition coefficients of the solutes, KL were also calculated. Finally, two the values of two factors important from separation point of view: selectivity (S12∞) and capacity (k2) at infinite dilution for few separation problems as hexane/benzene, cyclohexane/benzene, heptane/thiophene, and heptane/pyridine were calculated from γ13∞ and compared to literature values for other ionic liquids taken from available literature. Moreover, physicochemical properties of pure IL including liquid density and dynamic viscosity data, important from the technological point of view was determined at a wide temperature range.

Effect of asphaltene content in bitumen on thermodynamic properties of light hydrocarbons dissolving in bitumen

Solvent recovery from diluted bitumen and froth treatment tailings, produced during the bitumen recovery process for mined oil sands, requires an understanding of the thermodynamic equilibrium and kinetics of solvent dissolution in bitumen. Thermodynamic properties of solvent in bitumen having various asphaltene contents are needed in order to model and improve the solvent recovery process. In this work, the thermodynamic properties of light hydrocarbons in bitumen were investigated using an inverse gas liquid chromatography (IGC) method. Bitumen containing different amounts of asphaltenes (0 wt%, 2.6 wt%, 9.9 wt%, 36.9 wt%, and 53.7 wt%) were used as the stationary phase of the chromatographic column, while light hydrocarbons were injected into mobile phase. The specific retention volumes of the hydrocarbons in bitumen, Vgo, were measured at different temperatures (333.2 K–393.2 K). Thermodynamic properties of these light hydrocarbons in bitumen, including infinite dilution activity coefficient, γ∞, enthalpy of solution, ΔHo, heat capacity changes, ΔCpo, Gibbs energy change, ΔGo, as well as entropy of solution change, ΔSo, were then calculated based on thermodynamic principles and data obtained from IGC measurements.

Space filling of permethylated β‐cyclodextrin by volatile hydrophobic and hydrophilic guests in polyethylene glycol

The inclusion of volatile organic compounds of various classes in the permethylated β‐cyclodextrin in an oligomeric solution of polyethylene glycol was investigated by inverse gas–liquid chromatography methods and by a stereochemical approach. It was established that the “guest–host” complexation process is influenced by the geometrical structure of the guest molecules, their chirality, and entropy factors.

Determination of Activity Coefficients at Infinite Dilution of Solutes in N,N′-Di(2-ethylhexyl)isobutyramide Using Inverse Gas–Liquid Chromatography

Activity coefficients at infinite dilution for 30 solutes (alkanes, alkenes, alkyl benzenes, ketones, chloromethanes, aromatic compounds, acetonitrile, formaldehyde, and ethyl acetate) in N,N′-di(2-ethylhexyl)isobutyramide have been determined at temperatures T = (323.15 to 373.15) K by inverse gas chromatographic technique. Net retention volumes of solutes have been measured as a function of temperature. From the temperature dependence of the activity coefficients at infinite dilution, partial molar excess enthalpies and activity coefficients at infinite dilution at 298.15 K of solutes in N,N′-di(2-ethylhexyl)isobutyramide have been derived. Selectivity values at infinite dilution have been computed from the activity coefficients at infinite dilution values.

Study of benzyl- or cyclohexyl-functionalized ionic liquids using inverse gas chromatography

Inverse gas-liquid chromatography has been used to measure infinite dilution activity coefficients and gas-to-ionic liquid partition coefficients for a chemically diverse set of organic solutes dissolved in 1-benzyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-benzyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-cyclohexylmethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and N-cyclohexylmethylpyridinium bis(trifluoromethylsulfonyl)imide ionic liquids in the temperature range from 323.15K to 373.15K. The measured experimental data were extrapolated to 298.15K and the resulting values correlated mathematically with the Abraham solvation parameter model. The derived Abraham model correlations rigorously describe the experimental partition coefficient data to within 0.14 (or fewer) log units.

Separation of aliphatic from aromatic hydrocarbons and sulphur compounds from fuel based on measurements of activity coefficients at infinite dilution for organic solutes and water in the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxy-ethyl)ammonium bis(trifluoromethylsulfonyl)imide

The activity coefficients at infinite dilution, γ13∞, for 53 different solutes including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, ethers, ketones, thiophene, acetonitrile, pyridine, 1-nitropropane and water in the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide, [COC2N1,2,2][NTf2] were determined using inverse gas-liquid chromatography. The experiment has been performed at five temperatures over the range of (318.15 to 358.15)K. From experimental results, the partial molar excess Gibbs energy, ΔG1E,∞, enthalpy ΔH1E,∞ and entropy term TrefΔS1E,∞ at infinite dilution were calculated. Additionally, the gas-liquid partition coefficients of the solutes, KL were calculated. The value of selectivity, S12∞ and capacity, k2∞ at infinite dilution for hexane/benzene, cyclohexane/benzene, heptane/thiophene and heptane/pyridine separation processes were calculated directly from γ13∞. These parameters are compared to literature values of S12∞ and k2∞ for other ionic liquids and NMP, or sulfolane – solvents commercially used on an industrial scale in separation processes. Moreover, physicochemical properties of pure ILs that is: density, viscosity and surface tension have been determined as a function of temperature and basic thermal properties of pure [COC2N1,2,2][NTf2] were measured using DSC technique.

Inverse Gas–Liquid Chromatography Study of Asphalt Composition and Oxidative Aging

The chemical composition of an asphalt binder significantly affects oxidative aging and interactions with both aggregate and binder modifiers. In turn, it may cause premature asphalt pavement failures through fatigue cracking, moisture damage, or other failure mechanisms. Analytical chemical procedures, such as ion exchange chromatography, are time-consuming and cost prohibitive as routine tests. Inverse gas–liquid chromatography (IGLC) is a relatively faster and simpler technique that provides the chemical composition and polarity characteristics of asphalt samples. In IGLC, asphalt is used as the liquid substrate on an inert support in a GLC column and is characterized by measuring the retention behavior of selected test compounds that possess different functional groups. The interaction behaviors between seven test compounds and 19 unaged and GLC column–aged asphalt samples were determined and compared with functional group concentrations presented in the asphalts and in a nonaqueous potentiometric titration study. It was found that the retention behaviors of the test compounds are strongly related to the types and concentrations of functional groups in the asphalt. For unaged asphalts, the retention behavior of strongly basic test compounds is highly correlated with the concentration of acidic functional groups in asphalts. The retention behavior of phenol with oxidatively aged asphalts is highly correlated with the concentration of sulfoxide, one of the major products of asphalt oxidation.

Inverse Gas–Liquid Chromatography Study of Asphalt Composition and Oxidative Aging

The chemical composition of an asphalt binder significantly affects oxidative aging and interactions with both aggregate and binder modifiers. In turn, it may cause premature asphalt pavement failures through fatigue cracking, moisture damage, or other failure mechanisms. Analytical chemical procedures, such as ion exchange chromatography, are time-consuming and cost prohibitive as routine tests. Inverse gas-liquid chromatography (IGLC) is a relatively faster and simpler technique that provides the chemical composition and polarity characteristics of asphalt samples. In IGLC, asphalt is used as the liquid substrate on an inert support in a GLC column and is characterized by measuring the retention behavior of selected test compounds that possess different functional groups. The interaction behaviors between seven test compounds and 19 unaged and GLC column-aged asphalt samples were determined and compared with functional group concentrations presented in the asphalts and in a nonaqueous potentiometric titration study. It was found that the retention behaviors of the test compounds are strongly related to the types and concentrations of functional groups in the asphalt. For unaged asphalts, the retention behavior of strongly basic test compounds is highly correlated with the concentration of acidic functional groups in asphalts. The retention behavior of phenol with oxidatively aged asphalts is highly correlated with the concentration of sulfoxide, one of the major products of asphalt oxidation.

INVESTIGATION AND EVALUATION OF PETROLEUM ASPHALT AGING PROPERTY ON OXYGEN ABSORPTION BY INVERSE GAS LIQUID CHROMATOGRAPHY

ABSTRACT The aging mechanisms and performances on oxygen absorption of ten petroleum asphalts were studied and evaluated by the inverse gas liquid chromatography with the Aging Comprehensive Index, the Aging Subtraction Number, the Aging Total Area and the Aging Character Factor methods based on the changes of the retention coefficients of analytical compounds in the petroleum asphalt chromatographic column during continuous aging caused by oxygen absorption under an oxygen flow rate of 15∼30 ml/min at 140°C, after the inert support was evenly coated with toluene-dissolved petroleum asphalt and packed into the chromatographic column. The relative polarity of petroleum asphalt and the retention coefficients of analytical compounds increase after absorbing oxygen and the changes of the retention coefficients of the oxygen-containing analytical compounds, especially phenol are evidently greater than those of the nitrogen and sulfur-containing and aromatic analytical compounds. There are obvious differences between the retention coefficients of analytical compounds in the petroleum asphalt columns from different sources and between their changes with the aging on oxygen absorption. The repeated determinations of these evaluation methods show that the standard deviations are less than 1.63 and the variable coefficients under 0.2. The test data are found.to be reliable by Grubhs examination at 95% confidence level. Of the four evaluation methods the Aging Subtraction Number method is the most simple and convenient in operation and takes least time in evaluation.

Investigations on Romashkino asphaltic bitumen. 3. Fractionation of asphaltenes using ion-exchange chromatography

The fractionation of asphaltenes originally separated 1 from Romashkino asphaltic bitumen has been achieved by means of stepwise anion- and cation-exchange chromatography through macroreticular resins. The fractionation procedure and yields of the fractions are given. A detailed structural analysis has been made of original asphaltenes and their acid- and base-free fraction using elemental and densimetric analyses, gel-permeation chromatography and proton magnetic resonance spectroscopy. Inverse gas-liquid chromatography has also been used to detect the chemical functionality of the asphaltene fractions. Results are presented to show the effect of ion-exchange resins treatment upon the composition of asphaltenes, noting that molecular weight as well as chemical structure changes appreciably.

Investigations on Romashkino asphaltic bitumen.2. Study of maltenes fractions using inverse gas-liquid chromatography

Inverse gas—liquid chromatography (IGLC) has been used to investigate the chemical functionality of the various maltenes fractions obtained and identified in the previous study 1. The effectiveness of the separation of maltenes by ion-exchange chromatography has been ascertained. Results of analysis by IGLC indicated significant variation in interaction coefficient ( p ) values of the fractions. Acidic and basic fractions were shown to interact strongly with many test compounds. Based on these studies, interpretation of the behaviour in l p values with the chemical composition of the fractions has been given.

A study of asphalt-aggregate interactions using inverse gas-liquid chromatography

A study of asphalt-aggregate interactions using inverse gas-liquid chromatography

Inverse gas—liquid chromatography for detection of order—disorder in poly(vinyl chloride)

Inverse gas—liquid chromatography for detection of order—disorder in poly(vinyl chloride)

Adaptation of inverse gas-liquid chromatography to asphalt oxidation studies

Adaptation of inverse gas-liquid chromatography to asphalt oxidation studies

Inverse Gas-Liquid Chromatography. A New Approach for Studying Petroleum Asphalts.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInverse Gas-Liquid Chromatography. A New Approach for Studying Petroleum Asphalts.T. C. Davis, J. C. Petersen, and W. E. HainesCite this: Anal. Chem. 1966, 38, 2, 241–243Publication Date (Print):February 1, 1966Publication History Published online1 May 2002Published inissue 1 February 1966https://doi.org/10.1021/ac60234a023RIGHTS & PERMISSIONSArticle Views111Altmetric-Citations51LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (408 KB) Get e-Alerts Get e-Alerts