Binary Systems Methanol Research Articles

Solubility Reinforcement using Binary Solvent Mixtures and its use in Development and Validation of UV-Spectrophotometric Method for Posaconazole

Objectives: To develop a method that meets the requirements as per ICH guidelines for validation and can be used as simple, specific, economical, and repeatable for routine quality control analysis of formulations containing Posaconazole. Materials and Methods: The maximum absorbance of Posaconazole was successfully recorded using a precise 1:1 ratio of binary solvent system Methanol: Buffersolution pH 7.4 at 262nm. Results: After a preliminary physicochemical investigation the precipitation of the Posaconazole issue was resolved using a precise 1:1 ratio of binary solvent system Methanol: Buffersolution pH 7.4. Development and validation of the analytical method was done using the same binary solvent system. The maximum absorbance with this solvent system was found at 262nm, while the calibration curve shows a Regression coefficient (R2) of about 0.9984 for its linearity in the concentration range of 2.5 to 15µ/ml. The developed method was validated and meets the requirements as per ICH (International Conference for Harmonization) guidelines where the Limit of Detection (LOD) as well as Limit of Quantification (LOQ) were noted as 0.74µ/ml and 2.25µ/ml. Percentage recovery was within the permissible range (with a % relative standard deviation of less than 2.0). Conclusion: The results from validation parameters specifically accuracy or % recovery and robustness study reveal that the developed method meets the requirements and can be used as simple, specific, economical, and repeatable for routine quality control analysis of formulations containing Posaconazole.

Self-Diffusion and Molecular Association in a Cyclohexane–Methanol Binary System at Temperatures of 298 and 323 K

Self-Diffusion and Molecular Association in a Cyclohexane–Methanol Binary System at Temperatures of 298 and 323 K

Development and validation of liquid chromatography-tandem mass spectrometry method for the estimation of a potential genotoxic impurity 2-(2-chloroethoxy)ethanol in hydroxyzine.

2-(2-Chloroethoxy)ethanol (CEE) belongs to the so-called cohort of concerns which were classified as highly potent mutagenic carcinogens by the World Health Organization. It is widely used in the synthesis of the essential anti-histamine drug hydroxyzine. In addition, it is used as a primary solvent in dyes, nitrocellulose, paints, inks and resins. Owing to its potential genotoxicity, an efficient liquid chromatography-tandem mass spectrometry method was developed for the quantitative estimation of CEE traces in an active pharmaceutical ingredients and in tablet dosage forms of hydroxyzine-free base. The chromatographic separation was achieved on a C18 column using a gradient elution mode with a binary solvent system (ammonium formate and methanol). Mass detection was performed for CEE using a positive mode with selected ion monitoring technique at m/z value of [M + NH4 ]+ . The developed method was validated as per the International Conference on Harmonizaiton guidelines. The quantitation limit, linearity and recoveries were found to be 0.56 ppm, 0.56-7.49 ppm (r2 > 0.9985) and 93.6-99.3%, respectively. The proposed method was highly compatible and was used effectively to estimate CEE traces in different stages of drug synthesis and in tablet dosage forms of hydroxyzine for routine and stability testing.

Consistency test and prediction of experimental data from binary systems methanol + acetic acid and methanol + water in vapor-liquid equilibrium

Consistency test and prediction of experimental data from binary systems methanol + acetic acid and methanol + water in vapor-liquid equilibrium

Solubility and thermodynamic properties of azlocillin in pure and binary solvent systems

The solubility data of azlocillin (ALPC) in nine mono-solvents (methanol, ethanol, isopropanol, methyl acetate, ethyl acetate, isopropyl acetate, acetone, acetonitrile, tetrahydrofuran) and two different binary solvent systems (methanol + isopropanol, ethanol + isopropanol), under atmospheric pressure, were experimentally measured via a static gravimetric method in the temperature range from 278.15 K to 323.15 K. According to the experimental results, it could be found that the solubility of ALPC in all the tested pure and binary solvent systems increased with the rise of temperature at the measurable ranges. The solubility order of ALPC in the nine mono-solvents is generally ranked as: (ethanol or tetrahydrofuran) > acetone > (methanol or acetonitrile) > methyl acetate > ethyl acetate > isopropanol > isopropyl acetate. The solubility data of ALPC in both binary solvent systems increase with the increasing of mole fraction of methanol or ethanol. The modified Apelblat equation, λh equation, and NRTL model were applied to correlate the experimental solubility data of ALPC in pure and mixed solvent systems while the CNIBS/R-K model was also used for the mixed solvent systems. Finally, the mixing and dissolution thermodynamic properties of ALPC in the studied systems were calculated by the NRTL model and were analyzed. It was found that the mixing and dissolution processes of ALPC in the tested systems were spontaneous, endothermic and entropy-driven.

Isothermal vapor–liquid equilibria at 383.15–413.15 K for the binary system methanol + dimethyl carbonate and the pressure dependency of the azeotropic point

The objective of this work was to study the behavior of the azeotropic points of the methanol + DMC system under elevated pressures. We obtained isothermal vapor–liquid equilibria (VLE) data for this system at 383.15, 403.15, and 413.15 K by a static method. The azeotropic points were determined from the experimental VLE data. The temperature and pressure dependencies of the determined azeotropic points are discussed and compared with ones measured at reduced pressure. The experimental VLE data were represented by two activity coefficient models (non-random two-liquid and Wilson models). We also tested the modified UNIFAC (Dortmund) model for prediction of the VLE and azeotropic points. The azeotropic points of this system could be obtained over the pressure range from reduced pressures to elevated ones.

Effect of Addition of Salts on Excess Enthalpy in Methanol–Carbon Tetrachloride Mixture

The effect of dissolved sodium acetate (5 and 10%), potassium acetate (5 and 10%) and zinc acetate (5 and 10%) on the endothermic enthalpy of mixing in the binary system methanol–carbon tetrachloride has been investigated at 303.15 K in a displacement calorimeter with vapor space. Experimental values were fitted into a Redlich–Kister equation. Experimental values and predicted values were plotted against mole fraction of methanol and deviations were reported. The data obtained may be of interest to specialists in the field of thermodynamic of solutions.

Controlling breath figure patterns on PDMS by concentration variation of ethanol-methanol binary vapors.

In this paper, the self-assembly of condensed droplets on smooth and constrained surfaces under saturated vapor atmosphere of ethanol and methanol binary system is reported. Hexagonally ordered array of pores are obtained on smooth surfaces with saturated vapors of binary liquids without the assistance of any additives. The results show that the addition of a small amount of ethanol to methanol plays a role very similar to that of surface active agents in inducing the formation of a regular droplet array. The effect of constraints on a self-assembled droplet pattern such as the movement of the contact line and the depinning of the contact line is also investigated. It is observed that the pore size, pore shape, pore depth and ring diameter are influenced by the atmosphere of binary vapors in addition to the commonly held attribution to the surface tension of the solvent. Contact angle studies of the patterned substrates show hydrophobicity with high adhesiveness and transitions between the Wenzel and Cassie impregnating state over the entire concentration region.

Finite-Size Effects of Binary Mutual Diffusion Coefficients from Molecular Dynamics.

Molecular dynamics simulations were performed for the prediction of the finite-size effects of Maxwell-Stefan diffusion coefficients of molecular mixtures and a wide variety of binary Lennard–Jones systems. A strong dependency of computed diffusivities on the system size was observed. Computed diffusivities were found to increase with the number of molecules. We propose a correction for the extrapolation of Maxwell–Stefan diffusion coefficients to the thermodynamic limit, based on the study by Yeh and Hummer (J. Phys. Chem. B, 2004, 108, 15873−15879). The proposed correction is a function of the viscosity of the system, the size of the simulation box, and the thermodynamic factor, which is a measure for the nonideality of the mixture. Verification is carried out for more than 200 distinct binary Lennard–Jones systems, as well as 9 binary systems of methanol, water, ethanol, acetone, methylamine, and carbon tetrachloride. Significant deviations between finite-size Maxwell–Stefan diffusivities and the corresponding diffusivities at the thermodynamic limit were found for mixtures close to demixing. In these cases, the finite-size correction can be even larger than the simulated (finite-size) Maxwell–Stefan diffusivity. Our results show that considering these finite-size effects is crucial and that the suggested correction allows for reliable computations.

Measurement and Correlation of the Solubility of 2,6-Dihydroxybenzoic Acid in Alcohols and Binary Solvents

Experimental data on the solubility of 2,6-dihydroxybenzoic acid (2,6-DHBA) in methanol, ethanol, 2-propanol, 1-butanol, and three binary solvent systems (methanol + water, ethanol + water, and 2-propanol + water) from (278.15 to 318.15) K were measured by the gravimetric method. The experimental results indicated that the solubility of 2,6-DHBA in those solvents increased with increasing temperature. The solubilities of 2,6-DHBA in different pure solvents accorded with the following order: 1-butanol < methanol < ethanol < 2-propanol. In the binary solvent systems, the solubility decreased with increasing mole ratio of water. The experimental solubility data were correlated by the modified Apelblat equation. The NIBS/Redlich–Kister model was introduced to correlate the solubility data in the binary solvent systems.

Vapor–Liquid Equilibrium and Excess Enthalpy Data for Systems Containing N,N-Dimethylacetamide

Isothermal P–x vapor–liquid equilibrium and excess enthalpy (HE) data were experimentally determined for the 10 binary systems hexane, heptane, 1-octene, benzene, toluene, ethanol, methanol, ethyl acetate, dibutyl ether, and dichloromethane with N,N- dimethylacetamide using the static synthetic method and isothermal flow calorimetry, respectively. The experimental data from this work together with data taken from literature were used for the extension of the group contribution method Modified UNIFAC (Dortmund).

Vapor-liquid equilibria, density and sound velocity measurements of (water or methanol or ethanol + 1,3-propanediol) binary systems at different temperatures

In this work, vapor liquid equilibria (VLE) data for the binary systems containing {water or methanol (1)+1,3-propanediol (2)} are reported. All measurements were performed in the temperature range of (273.15–343.15 (or 363.15)) K over the whole composition range. The experimental data were correlated using the NRTL, UNIQUAC and Modified UNIFAC (Do) models. Additionally, the experimental measurements of densities and sound velocities were measured for binary systems (water or methanol or ethanol (1)+1,3-propanediol (2)) at atmospheric pressure and at (283.15, 293.15, 303.15 and 313.15)K. The excess/deviation functions were calculated and correlated using the Redlich-Kister polynomial equation.

Isobaric Vapor–Liquid Equilibria for Binary Mixtures of γ-Valerolactone + Methanol, Ethanol, and 2-Propanol

γ-valerolactone (GVL) has been identified as a renewable, versatile, and nontoxic building block for the chemical industry. Although several protocols were published for its synthesis, so far only a few studies concerning the separation and purification of the product were reported. Some of the procedures involve alcohols or lead to the formation of binary mixtures of alcohols and GVL, therefore the separation is of utmost importance to produce GVL. Isobaric vapor–liquid equilibria of three binary systems (methanol, ethanol, and 2-propanol) of γ-valerolactone were measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson and UNIQUAC activity coefficient models and the results were compared with UNIFAC model calculations. Both models were found suitable for representing the VLE data. The refractive indexes of all systems were determined in the whole concentration range at T = 293.2 and 298.2 K. Good agreements between experimental and calculated V...

Vapor–Liquid Equilibria Measurement of (Methanol + Ethanenitrile + Bis(trifluoromethylsulfonyl) Imide)-Based Ionic Liquids at 101.3 kPa

Isobaric vapor–liquid equilibria (VLE) data of the ternary system methanol + ethanenitrile +1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][NTf2]) and methanol + ethanenitrile +1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([BMIM][NTf2]) as well as their binary system methanol + ethanenitrile (MeCN) were obtained using a improved Othmer still at 101.3 kPa. Results indicated that the addition of [EMIM][NTf2] or [BMIM][NTf2] can eliminate the azeotropic phenomenon of the binary system of methanol + MeCN when the mole fraction of the ionic liquids reach 0.05. Besides, the measured ternary data were well fitted with the nonrandom two-liquid model.

Measurement and correlation of isobaric vapor-liquid equilibria of methanol + tetrahydrofuran + 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at 101.3 kPa

We investigated the isobaric vapor-liquid equilibria (VLE) of the binary system methanol + tetrahydrofuran (THF), the ternary system methanol + THF + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][NTf2]), as well as methanol + THF + 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][NTf2]) in a modified Othmer still. The results indicated that the ionic liquids ([BMIM][NTf2] and [HMIM][NTf2]) produced a consistent salting-in effect of THF, resulting in the incremental relative volatility of methanol to THF. The experimental data were correlated using the e-NRTL model, and the parameters were obtained with a good consistency. The ionic liquids even eliminated the azeotropic phenomenon when the mole ratio of [BMIM][NTf2] was up to 0.173 and [HMIM][NTf2] up to 0.128 as calculated by the e-NRTL model. [HMIM][NTf2] had a stronger effect on the separation of azeotropic mixtures than [BMIM][NTf2] did.

Density and Excess Molar Volumes of 1-Butanol + Methanol + Electrolyte Systems in the Temperature Range 293.15–308.15 K

Methanol, unlike water, is miscible with 1-butanol in all proportions however not much work is available on binary mixtures of the two alcohols. Investigation of 1-butanol–methanol binary system (the mixture) can be interesting also for its general and industrial applications. In the present study densities over the entire composition range of the mixture have been measured from 293.15 to 308.15 K, which allowed determination of excess molar volume (VE) at four different temperatures. Structural information on the mixture has been obtained by adding sparingly soluble NaCl, KCl (borderline) and fairly soluble CdI2 (structure-breaker). Limited solubility of NaCl and KCl restricted the study only to their saturated solutions in the mixture. On the other hand using density data of CdI2 solutions of different molalities (from 4.0·10–3 to 8.0·10–2 mol·kg–1) in the mixture at the above temperatures, apparent molar (VΦ) and partial molal (Vm°) volumes of CdI2 have been determined. The data also enabled determinat...

Isobaric Vapor–Liquid Equilibrium for Methanol + Dimethyl Carbonate + Trifluoromethanesulfonate-based Ionic Liquids at 101.3 kPa

Isobaric vapor–liquid equilibrium (VLE) data for the binary system methanol + dimethyl carbonate as well as the VLE data for the ternary systems methanol + dimethyl carbonate +1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]) and methanol + dimethyl carbonate + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][OTf]) at 101.3 kPa have been obtained with a modified Othmer still. The results indicated that both [EMIM][OTf] and [BMIM][OTf] produced crossover effects. Due to the difference of polarity of the two ILs, [BMIM][OTf] eliminated the azeotropic point at mole fraction about 10%, whereas [EMIM][OTf] only pulled down the azeotropic point. The measured VLE data were fitted using the NRTL model with a good consistency.

Application of Mechanical Vapor Recompression to Acetone – Methanol Separation

 Abstract—This paper proposed a novel integrated design of azeotropic mixtures distillation process based on mechanical vapor recompression (MVR). The extractive distillation of acetone - methanol binary system that forms a homogeneous minimum - boiling azeotrope was studied. Based on the simulation result, the total energy consumption of the proposed sequence is 62% less than the existing extractive distillation configuration.

Correction to “Comments on ‘Experimental Measurements of Vapor–Liquid Equilibrium Data for the Binary Systems of Methanol + 2-Butyl Acetate, 2-Butyl Alcohol + 2-Butyl Acetate, and Methyl Acetate + 2-Butyl Acetate at 101.33 kPa’”

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionCorrection to “Comments on ‘Experimental Measurements of Vapor–Liquid Equilibrium Data for the Binary Systems of Methanol + 2-Butyl Acetate, 2-Butyl Alcohol + 2-Butyl Acetate, and Methyl Acetate + 2-Butyl Acetate at 101.33 kPa’” Jaime Wisniak†, José R. Pérez-Correa‡, Andrés Mejía§, and Hugo Segura§View Author Information† Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel‡ Escuela de Ingeniería, Departamento de Ingeniería Química y Bioprocesos, Pontificia Universidad Católica de Chile, Macul, Santiago 7820436, Chile§ Departamento de Ingeniería Química, Universidad de Concepción, Concepción 4070386, ChileCite this: J. Chem. Eng. Data 2014, 59, 3, 942Publication Date (Web):February 17, 2014Publication History Published online17 February 2014Published inissue 13 March 2014https://doi.org/10.1021/je500041jCopyright © 2014 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views302Altmetric-Citations3LEARN 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 (134 KB) Get e-Alerts Get e-Alerts

Effects of temperature and concentration on interactions in methanol + ethyl acetate and ethanol + methyl acetate or ethyl acetate systems: Insights from apparent molar volume and apparent molar isentropic compressibility study

The density (d) and speed of sound (u) for the binary systems (methanol+ethyl acetate) and (ethanol+methyl acetate or ethyl acetate) were measured at 298.15, 303.15, 308.15 and 313.15K and at atmospheric pressure in this work whereas the system (methanol+methyl acetate) was measured in the literature. The apparent molar volume, Vφ, isentropic compressibility, ks, and apparent molar isentropic compressibility, kφ, have been calculated using density and speed of sound data, respectively. The limiting apparent molar volume, Vφ0, and limiting apparent molar isentropic compressibility, kφ0, were found by extrapolation to infinite dilution using the Redlich–Mayer equation. The limiting apparent molar volume was used to obtain information about (solute–solvent) and (solute–solute) interactions. The temperature dependence of apparent molar volumes were used to calculate the apparent molar expansibility, Eφ0, and Hepler's constant, (∂2Vφ0/∂T2)P. The isobaric thermal expansion coefficient, αP, was also calculated. Positive kφ0 values for all binary systems can be attributed to the predominance of solvent intrinsic compressibility over the solute intrinsic effect.