scholarly journals Stability Analysis of Binary Solvent Mixtures for Herbal Phytochemical Extraction

2017 ◽  
Vol 5 (3) ◽  
pp. 128-133
Author(s):  
Siti Nuurul Huda Mohammad Azmin ◽  
Nor Alafiza Yunus ◽  
Sharifah Rafidah Wan Alwi ◽  
Mohd Shukri Mat Nor
Keyword(s):  
Molar Fraction ◽  
Solvent Mixture ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Energy Of Mixing ◽  
Gibbs Energy Of Mixing ◽  
Extraction Processes ◽  
The Stability ◽  
Phytochemical Extraction

Most of the extraction processes of herbal phytochemicals use solvent mixtures as a phytochemical transfer mediums. It is very important to predict the stability of solvent mixtures before it is used to extract herbal phytochemicals. In order to prevent any disturbance in the herbal extraction, the solvent mixtures must be in a single liquid phase (miscible to each other). In this study, the stabilities of five binary solvents (methanol-water, methanol-ethyl acetate, methanol-acetic acid, methanol-n-propionaldehyde, and methanol-isobutyraldehyde mixtures) that could be used in the current extraction processes are evaluated. The main purpose of this study is to evaluate these binary solvents in terms of their stability using Gibbs energy of mixing. The value of the function ?Gmix/RT is calculated for each solvent mixture. Then, the graph for ?Gmix/RT versus solvent molar fraction x is plotted. From this plot and the value of function ?Gmix/RT, it can be concluded whether the solvent mixtures are stable or unstable. From the analysis, all five binary mixtures are stable within the selected molar fraction making all mixtures are suitable to be applied in herbal extraction.

Solubility and Thermodynamic Properties of L-Proline in Methanol-Dichloromethane Mixtures

2015 ◽  
Vol 775 ◽  
pp. 185-190
Author(s):  
Zi Dan Chen ◽  
Kun Kun Wang ◽  
Xue Li ◽  
Sheng Wang ◽  
Sha Wu ◽  
...  
Keyword(s):  
Dynamic Method ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Purification Process ◽  
Apelblat Equation ◽  
Modified Apelblat Equation ◽  
Monitoring Technique ◽  
Laser Monitoring ◽  
Hoff Equation

The solubility of L-proline in binary solvents of methanol and dichloromethane were measured by a dynamic method via a laser monitoring technique. In the binary solvent mixtures, the solubility increases with the increasing of temperature and proportion of the methanol. The experimental solubility were fitted to modified Apelblat equation and Van’t Hoff equation in this work can be used as essential data and models in the purification process of L-proline. The dissolving process is endothermic and the dissolution driving force converts from enthalpy-driving to entropy-driving.

scholarly journals Fast real-time monitoring of entacapone crystallization and characterization of polymorphs via Raman spectroscopy, statistics and SWAXS

2014 ◽  
Vol 64 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Tomislav Jednačak ◽  
Aden Hodzic ◽  
Otto Scheibelhofer ◽  
Marijan Marijan ◽  
Johannes G. Khinast ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Probe ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Starting Point ◽  
Principal Components Method ◽  
Components Method

Abstract Crystallization of the drug entacapone from binary solvent mixtures was monitored in situ using a Raman optical probe. The recorded Raman spectra and statistical analysis, which included the principal components method and indirect hard modeling made it possible to estimate the starting point of crystallization, to assess crystallization temperatures and to provide information on the polymorphic content of the mixture. It was established that crystallization temperatures were proportional to the volume content of the solvent in mixtures. The samples were also evaluated off-line via Raman spectroscopy and SWAXS. The collected data showed the presence of forms b and g in all solvent mixtures. In a toluene/methanol 30:70 mixture, in addition to forms b and g, at least one of the forms A, D or a was also indicated by SWAXS. The results have shown that the presence of a particular polymorph is strongly dependent on the nature and portion of the solvent in the binary solvent mixture.

scholarly journals Thermodynamic Studies of Complexes of Amlodipine Besylate with Ni2+, Mg2+, Co2+ and Ca2+ cations in pure and in mixed binary solvent systems at 303.15, 313.15 and 323.15 K by Conductometric Method

2020 ◽  
Vol 13 (1) ◽  
pp. 206-216
Author(s):  
Dhruvi. R. Mehta ◽  
Raviprakash S. Chandra ◽  
M. M. Maisuria
Keyword(s):  
Driving Force ◽  
Binary Solvent ◽  
Complexation Reaction ◽  
Solvent Mixtures ◽  
Amlodipine Besylate ◽  
Linear Change ◽  
Conductometric Method ◽  
Binary Solvent Systems ◽  
Solvent Systems ◽  
The Stability

The present work relates to the complexation reaction between Amlodipine Besylate[AML] with Ni2+, Mg2+, Co2+ and Ca2+ cation in dimethylsulfoxide (DMSO), pure methanol (MeOH) and their binary mixtures(DMSO-MeOH and DMSO-Water) by conductometric method. The conductance data show that the stoichiometry of the complexes formed between AML with Ni2+, Mg2+, Co2+ and Ca2+ cation in pure DMSO, pure MeOHas well as in the binary solvent mixtures was 1:1. The stability of AML complexes with Ni2+ , Mg2+, Co2+ and Ca2+ metal ion was observed to be sensitive to the nature of the solvent system. In case of DMSO-Water binary solvent systems there was a linear change in LogKf values but in case of DMSO-MeOH binary solvent systems non linear change in LogKf values observed.The negative values of ΔG0 show that the reaction is spontaneous and ability of the AML ligand to form stable complexes. However, the result shows positive value of ΔH0 which indicates that enthalpy is not driving force for the formation of the complexes. Furthermore, the positive value of ΔS0 indicates that entropy is a driving force for the complexation. The values of ΔH0 and ΔS0 for formation of the complexes were obtained from temperature dependence of the stability constants.

scholarly journals Screening Metal–Organic Frameworks for Separation of Binary Solvent Mixtures by Compact NMR Relaxometry

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3481
Author(s):  
Marc Wagemann ◽  
Natalia Radzik ◽  
Artur Krzyżak ◽  
Alina Adams
Keyword(s):  
Separation Efficiency ◽  
Metal Organic Frameworks ◽  
Solvent Mixture ◽  
Proton Nuclear Magnetic Resonance ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Separation And Purification ◽  
Nmr Relaxometry ◽  
Metal Organic ◽  
Static Conditions

Metal–organic frameworks (MOFs) have great potential as an efficient alternative to current separation and purification procedures of a large variety of solvent mixtures—a critical process in many applications. Due to the huge number of existing MOFs, it is of key importance to identify high-throughput analytical tools, which can be used for their screening and performance ranking. In this context, the present work introduces a simple, fast, and inexpensive approach by compact low-field proton nuclear magnetic resonance (NMR) relaxometry to investigate the efficiency of MOF materials for the separation of a binary solvent mixture. The mass proportions of two solvents within a particular solvent mixture can be quantified before and after separation with the help of a priori established correlation curves relating the effective transverse relaxation times T2eff and the mass proportions of the two solvents. The new method is applied to test the separation efficiency of powdered UiO-66(Zr) for various solvent mixtures, including linear and cyclic alkanes and benzene derivate, under static conditions at room temperature. Its reliability is demonstrated by comparison with results from 1H liquid-state NMR spectroscopy.

scholarly journals Spectrophotometric and conductometric study of the complexation of N-salicylidene-2-aminophenol with Cu2+ in methanol + 1,4-dioxane binary solutions

2014 ◽  
Vol 79 (10) ◽  
pp. 1263-1277
Author(s):  
Rashmidipta Biswas ◽  
Dhiraj Brahman ◽  
Biswajit Sinha
Keyword(s):  
Stability Constants ◽  
Mixed Solvents ◽  
Molar Conductance ◽  
Binary Solvent ◽  
Complexation Reaction ◽  
Solvent Mixtures ◽  
Linear Behaviour ◽  
Different Temperatures ◽  
Conductometric Study ◽  
The Stability

The complexation reaction between N-salicylidene-2-aminophenol, abbreviated as SAP, with Cu2+ ion was studied in binary mixtures of methanol and 1,4-dioxane by using conductometric and spectrophotometric method at different temperatures. The stability constants (Kf) for the 1:1 complex, Cu2+-SAP, were calculated from computer fitting of absorbance and molar conductance data against various mole ratios (cM:cL or cL:cM) in different binary solvent mixtures. A non-linear behaviour was observed for the variation of logKf for the complex against the solvent compositions. Various thermodynamic parameters (?H, ?S and ?G) for the formation of Cu2+-SAP complex were determined from the temperature dependence of stability constants (Kf). The overall results showed that the complexation reaction is entropy driven and is affected by the nature and composition of the mixed solvents.

Swelling of Vulcanized Rubbers in Binary Solvent Mixtures

1965 ◽  
Vol 38 (4) ◽  
pp. 940-942
Author(s):  
J. Scanlan
Keyword(s):  
Ternary Systems ◽  
Interaction Constant ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures ◽  
Binary Solvent Mixture

Abstract The single-liquid approximation has been applied to the data of Bristow on ternary systems containing benzene and cyclohexane with one of the rubbers, natural, SBR, or butyl. Satisfactory fits are obtained with a constant value of the interaction constant between the two solvents χ12 which differs markedly, however, from the value obtained by measurements on the binary solvent mixture.

scholarly journals Review of the Cosolvency Models for Predicting Drug Solubility in Solvent Mixtures: An Update

2019 ◽  
Vol 22 ◽  
pp. 466-485 ◽  
Author(s):  
Abolghasem Jouyban
Keyword(s):  
Ab Initio ◽  
Mixed Solvents ◽  
Isothermal Condition ◽  
Solubility Data ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Mathematical Form ◽  
Independent Variables ◽  
Correlative Models

The cosolvency models frequently used in solubility data modeling of drugs in mixed solvents were reviewed and their accuracies for calculating the solubility of solutes were briefly discussed. The models could be used either for correlation of the generated solubility data with temperature, solvent composition etc or for prediction of unmeasured solubility data using interpolation/extrapolation technique. Concerning the correlation results employing a given number of independent variables, the accuracies of the investigated models were comparable, since they could be converted to a single mathematical form, however, the accuracies were decreased when models emplyed more independent variables. The accurate correlative models could be employed for prediction purpose and/or screening the experimental solubility data to detect possible outliers. With regard to prediction results, the best predictions were made using the cosolvency models trained by a minimum number of experimental data points and an ab initio accurate prediction is not possible so far and further mathematical efforts are needed to provide such a tool. To connect this gap between available accurate correlative models with the ab initio predictive model, the generally trained models for calculating the solubility of various drugs in different binary mixtures, various drugs in a given binary solvent and also a given drug in various binary solvents at isothermal condition and/or different temperatures were reported. Available accuracy criteria used in the recent publications were reviewed including mean percentage deviation (MPD). The MPD for correlative models is 1-10% whereas the corresponding range for predictive models is 10-80% depend on the model capability and the number of independent variables employed by the model. This is an update for a review article published in this journal in 2008.

scholarly journals Solvatochromic Study of Two Carbanion Monosubstituted 4-Tolyl-1,2,4-triazol-1-ium Phenacylids in Binary Hydroxyl Solvent Mixtures

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3910
Author(s):  
Dana Ortansa Dorohoi ◽  
Dan-Gheorghe Dimitriu ◽  
Mihaela Maria Dulcescu-Oprea ◽  
Ana Cezarina Morosanu ◽  
Nicoleta Puica-Melniciuc ◽  
...  
Keyword(s):  
Cell Model ◽  
Solvation Shell ◽  
Solvent Mixture ◽  
Point Of View ◽  
Visible Range ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixture ◽  
Spectral Shifts ◽  
The Difference

Two 4-tolyl-1,2,4-triazol-1-ium methylids, namely 4-tolyl-1,2,4-triazol-1-ium-phenacylid and 4-tolyl-1,2,4-triazol-1-ium-4′-nitro-phenacylid, are studied from solvatochromic point of view in binary solvent mixtures of water with ethanol and water with methanol. The contributions (expressed in percent) of the universal and specific interactions are separated from the spectral shifts recorded in the visible range for each composition of the binary solvent mixture. The essential role of the orientation and induction interactions in the studied solutions was demonstrated. Based on the statistic cell model of the binary solvent mixture solutions, the difference between the formation energies of ylid-water and ylid-alcohol complexes is estimated. The composition of the ylid’s first solvation shell was also established using the model of the binary solvent mixture solutions. The results obtained from the statistical cell model were compared with those obtained by using the Suppan’s model, resulting a good agreement.

scholarly journals Thermodynamics of the complexation between salicylaldehyde thiosemicarbazone with Cu2+ ion in methanol +1,4-dioxane binary solutions

2014 ◽  
Vol 79 (5) ◽  
pp. 565-578 ◽  
Author(s):  
Rashmidipta Biswas ◽  
Dhiraj Brahman ◽  
Biswajit Sinha
Keyword(s):  
Mixed Solvents ◽  
Formation Constants ◽  
Molar Conductance ◽  
Binary Solvent ◽  
Complexation Reaction ◽  
Solvent Mixtures ◽  
Conductance Data ◽  
Different Temperatures ◽  
Uv Visible ◽  
The Stability

The complexation reaction between salicylaldehyde thiosemicarbazone, abbreviated as STSC, with Cu2+ ion was studied in the binary mixtures of methanol + 1,4-dioxane binary by using UV-Visible spectrophotometric and conductometric methods at different temperatures. The formation constants (Kf) for the 1:1 complex, Cu2+-STSC, were calculated from computer fitting of the absorbance and molar conductance data against various mole ratios (cM:cL or cL:cM) in different binary solvent mixtures. A non-linear correlation was observed for the variation of logKf for the complex against the solvent compositions. Various thermodynamic parameters (?H, ?S and ?G) for the formation of Cu2+-STSC complex were also determined from the temperature dependence of the stability constants (Kf). The results showed that the complexation reaction is affected by the nature and composition of the mixed solvents.

Application of mixed solvents for elution of organophosphate pesticides extracted from raw propolis by matrix solid-phase dispersion and analysis by GC-MS

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Kati Medina-Dzul ◽  
David Muñoz-Rodríguez ◽  
Yolanda Moguel-Ordoñez ◽  
Cristian Carrera-Figueiras
Keyword(s):  
Solid Phase ◽  
Mixed Solvents ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Organophosphate Pesticides ◽  
Experimental Conditions ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Relative Standard

AbstractThe excessive application of organophosphate pesticides (OPPs) in crop fields close to hives and its application in beekeeping practices are potential sources of contamination of propolis. Pesticides were extracted from raw propolis by matrix solid-phase dispersion. Because of the complex chemical composition of propolis, binary solvent mixtures based on acetonitrile and a relatively non-polar solvent in different proportions were tested for the selective elution of OPPs. The effect of mixed solvents on clean-up was evaluated by GC-MS and the main interfering compounds co-eluted with pesticides were identified. In addition, three volumes of the solvent mixture and the volume of the sample were evaluated in an experimental factorial design. The final experimental conditions were 1 mL of dissolved propolis and 8 mL of acetonitrile/dichloromethane (g4 r = 25: 75). Mean recoveries ranged from 55 % to 96 % (relative standard deviation < 8 %) with an inter-day precision lower than 24 %. The proposed method was applied to the analysis of real samples obtained from local beekeepers.

Sign in / Sign up

Export Citation Format

Share Document