Quantitative solubility

Table 7 Semi-Quantitative Solubility Study Results...

Unfortunately, quantitative solubility data were obtained primarily for salts which are fairly soluble in NMA. Thus, values for the solubility products (and hence for the free energies of solution at infinite dilution) cannot be calculated from the solubility data with any degree of confidence as activity data are unavailable at the relevant concentrations. Nor can the temperature-dependent data of Chandra and Gopal be used to derive meaningful values for AHa (soln) for similar reasons. Pucci era/.141) have determined the solubility product of AgSCN in NMA to be 2 x 10 14 at 40 °C. 

The methods that have been used to purify metal derivatives of jS-keto imines are surprisingly limited. Generally, recrystallization has been used, with acetone, ethanol, and benzene as common solvents. Very few quantitative solubility data are available. However, the solubilities of 4,4 -(ethylenedinitrilo)di-2-pentanonatocopper(II) and its 1-hydrate in water and in 12% ethanol have been determined at several temperatures. ... 

Amino acid analysis is often touted as the most accurate method for determination of protein concentration. The data from this 1996 ABRF AAA study indicate that the vast majority of member facilities that participated in this study quantitate soluble protein well. The most striking aspect of this study, however, was the ability of the laboratories to identify the protein solely on its amino acid composition. The data from approximately 90% of the participants were sufficient for correct identification, if one knew the species of the protein s origin. Currently, identification of unknown proteins from AAA data is not frequently used for simple soluble proteins, such as triosephosphate isomerase. The technique is more commonly used to identify proteins that have been separated by two dimensional analysis on isoelectric focusing and SDS electrophoresis and then transferred to PVDF membranes. Such samples are usually present in low... 

The spectroscopic probe pyridine-N-oxide was used to characterize polar microdomains in reverse micelles in supercritical ethane from 50 to 300 bar. For both anionic and nonionic surfactants, the polarities of these microdomains were adjusted continuously over a wide range using modest pressure changes. The solubilization of water in the micelles increases significantly with the addition of the cosolvent octane or the co-surfactant octanol. Quantitative solubilities are reported for the first time for hydrophiles in reverse micelles in supercritical fluids. The amino acid tryptophan has been solubilized in ethane at the 0.1 wt.% level with the use of an anionic surfactant, sodium di-2-ethylhexyl sulfosuccinate (AOT). The existence of polar microdomains in aggregates in supercritical fluids at relatively low pressures, along with the adjustability of these domains with pressure, presents new possibilities for separation and reaction processes involving hydrophilic substances. 

Seidell, A. Solubilities of Inorganic and Organic Compounds A Compilation of Quantitative Solubility Data from the Periodical Literature D. Van Nostrand Company New York 1919. 

Although his work was primarily of a qualitative nature, the concept of a cloud point and a freezing (or melting) point depression of a solid can be extended to yield quantitative solubility information. The present day experimental techniques used to determine the melting point depression of a solid are covered in chapter 4. 

Quantitative solubility calculations are usually performed using equation of state methods (10). Kim, et al., (29), discuss solubility behavior in the immediate vicinity of the critical point using macroscopic thermodynamic properties. 

Table 14.102 Seml-Quantitative Solubilities of Inorganic Materials In DMF at25 C (11)... 

One of the simplest notions in chemistry is that like dissolves like. Qualitatively, like can be defined in terms of similar chemical groups or similar polarities. Quantitatively, solubility of one component in another is governed by the free energy of mixing, AGm (Eq. 23), where T is the absolute temperature, ASm is the entropy of mixing, and AHm is the enthalpy of mixing. 

Quantitatively, solubility of one component in another is governed by the familiar equation of the free energy of mixing. 

To assess the eutectic point variation with solution phase chemistry quantitatively, solubility equations that consider the appropriate contributions are considered. in terms of ionization for a (1 1) co-crystal of a non-ionized drug and an acidic co-former is ... 

Other physical constants, such as refractive index, optical rotation, semi-quantitative solubility determinations in solvents of different types, etc., are reserved until later in the course of analysis, since their application may possibly prove unnecessary. 

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