Higher solubility limitation

As mentioned already, for chemical treatment of other sulfate scales (BaSO or SrSO ), tetrasodium EDTA solution is preferable to other alternatives because of its higher pH (about 10.6). The dissolution process is increased at higher pH. Also, tetrasodium EDTA has a much higher solubility limit than the more acidic forms of EDTA. 

The poor solubility of higher sodium alkanesulfonates cited above is reflected in the surface tension vs. concentration plots of sodium pentadecane 4-sulfonate (Fig. 26). Because below the critical micelle concentration the solubility limit is reached, a break in the a-c plot occurs. The problem of solubility properties of alkanesulfonates below the point at which the hydrated crystals or solid... 

SFE can be carried out in three different ways. In a static extraction (no flow-rate), the extraction vessel is pressurised to the desired pressure with the extracting fluid and then simply left for a certain length of time. The main benefit of this method is that the fluid has time to penetrate the matrix. It is most applicable when the analyte has a high affinity for the solvent and a low affinity for the matrix and also when the solubility limit of the analyte in the fluid is much higher than the actual level reached during the extraction [89]. This method was popular in early SFE experiments but has declined in favour of dynamic SFE. Here, fresh SCF is continuously passed over the sample, extracting soluble compounds and depositing them in a suitable solvent or on a solid trap. The dynamic mode is particularly useful when the concentration of the solute... 

In such cases, the Nogami method can be applied to the early points curve (Fig. 6) and the solubility, S, of the polymorph can be assessed. One of the important aspects of metastable polymorphs in pharmacy is exactly their higher solubility, since the dissolution rate will also be higher [Eq. (7)]. Hence the bioavailability will be increased where this is dissolution rate limited [21]. 

To maximize the current limit that could be shunted by redox additives so that the occurrence of such irreversible processes due to overflowing current could be more efficiently suppressed, the redox additive apparently should be present in the electrolyte at high concentrations, and both its oxidized and reduced forms should be very mobile species. Where the criteria for selecting potential redox additives are concerned, these requirements can be translated into higher solubility in nonaqueous media and lower molecular weight. In addition to solubility and diffusion coefficients, the following requirements should also be met by the potential redox additives (1) the formal potential of the redox couple [R]/[0] should be lower than the onset potential for major decom-... 

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