scholarly journals Natural product mixture analysis by matrix-assisted DOSY using Brij surfactants in mixed solvents

RSC Advances ◽  
2014 ◽  
Vol 4 (79) ◽  
pp. 42029-42034 ◽  
Author(s):  
Mariano G. S. Vieira ◽  
Nilce V. Gramosa ◽  
Nágila M. P. S. Ricardo ◽  
Gareth A. Morris ◽  
Ralph W. Adams ◽  
...  

Brij surfactant micelles in mixed solvent systems aid resolution of natural product NMR signals in diffusion-ordered spectroscopy.

2020 ◽  
Vol 10 (3) ◽  
pp. 5355-5360

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.


2020 ◽  
Vol 10 (2) ◽  
pp. 5332-5337

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.


2020 ◽  
Vol 42 (1) ◽  
pp. 57-57
Author(s):  
Shamsher Ali Shamsher Ali ◽  
Shabir Hussain Shabir Hussain ◽  
Irfan Ali and Syed Azhar Ali Irfan Ali and Syed Azhar Ali

In this study, saturated solutions of Sr(OH)2 in pure water and in mixed solvent systems (methanol - water, ethanol - water, 1-propanol - water, and 2-propanol - water) at two temperatures were prepared and titrated with standard HCl solution by using pH metry. Using these titration data, the molar solubility (s), solubilty product (Ksp) and Gibbs free energy (Go), entropy change (ΔSand#176;) and enthalpy change (ΔHand#176;) for dissolution of strontium hydroxide was determined. At room temperature (20and#176;C), the s, Ksp, ∆Go were found to be 4.28 x 10-2 mol L-1, 3.13 x 10-4 mol3L-3 and 19.70 kJ mol-1 respectively. The ΔHand#176; and ΔSand#176; of the reaction is 2.90 kJ mol-1 and – 60.80 J. mol-1 K-1. With increasing percentage content of organic solvent in mixed solvents, the molar solubility and Ksp decreased and ∆Go, ΔHand#176; and ΔSand#176; values increased. The results were correlated with the dielectric constant value of the solvents used in the study.


2021 ◽  
Vol 65 (2) ◽  
Author(s):  
Susmita Kamila ◽  
Ganesh Durgachalam N

Abstract. Different metal ions as well as carbohydrates play vital role in human metabolism. The present investigation emphasizes on zinc sulphate (ZnSO4) in galactose and its comparative study with lactose in aqueous medium at 303.15, 308.15, 313.15K temperature and at 1.0 atmospheric pressure. Different physical quantities such as density, viscosity and speed of sound have been measured as function of concentrations and temperatures for these multi-component solutions. These quantities were further used to evaluate various thermo-acoustic parameters like acoustic impedance, isentropic compressibility, partial molal compressibility, partial molal volume, internal pressure etc,. The results were analyzed to assess the type and extent of association among the components. Moreover, both Zn2+ and SO42- are in the Hofmeister series and there is a possibility of ion-macro molecule interactions in aqueous solution. The breaking of the structure and the solvation of the solute by changing the temperature in mixed solvents are the point of discussion in the present study. Interestingly, the ion-solvation of zinc ion is comparatively more favorable in galactose than in lactose-water mixed solvent systems.   Resumen. Diferentes iones metálicos, así como carbohidratos juegan un papel vital en el metabolismo humano. La presente investigación centra su atención sobre el sulfato de zinc (ZnSO4) en galactosa y un estudio comparativo con lactosa en soluciones acuosas a las temperaturas 303.15, 308.15, 313.15K y 1 atm de presión. Se midieron diferentes cantidades físicas como densidad, viscosidad y velocidad del sonido como función de la concentración y la temperatura de las soluciones. Posteriormente, estas cantidades se utilizaron para evaluar distintos parámetros termoacústicos como impedancia acústica, compresibilidad isoentrópica, compresibilidad molal parcial, volumen molal parcial, presión interna, etc. Los resultados se analizaron para evaluar el tipo y grado de la asociación entre los componentes. Mas aún, tanto Zn2+ como SO42- están en las series de Hofmeister y hay una posibilidad de presencia de interacciones ión-macromolécula en la solución acuosa. Un punto de discusión en el presente estudio es el rompimiento de la estructura y la solvatación del soluto debidos al cambio de la temperatura de las soluciones. Es interesante hacer notar que la solvatación de los iones de zinc es comparativamente mas favorable en las soluciones acuosas de galactosa que de lactosa.


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