Pyrene, water solubility enhancement

Tanaka S, Oba K, Fukushima M, Nakayasu K, Hasebe K (1997) Water solubility enhancement of pyrene in the presence of humic substances. Anal Chim Acta 337 351-357... 

Water-soluble nickel salts enter the cells with relative ease but are less effective than crystalline particulates in the cell transformation assay, when using hamster cells [429, 430]. However, an enhancement of viral transformation of cells has been found [431, 432], In addition, a synergistic effect of cigarette smoke extracts, benzo[a]pyrene and nickel sulphate on the morphological transformation of hamster embryo cells has also been obtained [433], It was suggested that nickel salts are more potent as promoters than they are as initiators [434],... 

MECC separations are generally limited to compounds which are reasonably soluble in the mobile phase. In the case of normal micelles the sample components to be separated must have some solubility in the aqueous phase. It is interesting to note that good sample solubility in the aqueous-micelle mixture does not assure an effective separation. The addition of micelles to an aqueous solution can greatly increase the solubility of hydrophobic compounds. For example, the solubility of pyrene in water is enhanced by 10s when the water is made 0.07 M in SDS (2). However, all of the hydrophobic compounds in a mixture tend to be nearly completely solubilized by the micelles and elute from a MECC column poorly resolved, with retention times near tm. 

Enhancement of the Water Solubility of Organic Pollutants Such as Pyrene by Dissolved Organic Matter... 

Soon after the introduction of convergent dendrimer synthesis, " hemispherical, aryl-ester-coated, benzyl ether-based dendrons were reported. Attachment to a divalent core and conversion to the polycarboxylate 25 (Fig. 5) yielded dendriiners that facilitated a 200-fold increase in pyrene (26) solubility in water eompared with that of pure water without the dendrimer. Notably, use of sodium dodecyl sulfate (SDS above cmc 9 X 10 M) for pyrene encapsulation resulted in only an 100-fold enhancement. 

These compounds are another example of nonionic, nonpolar compounds. They are found in trace levels in water and result from combustion processes and hydrocarbon spills. They are trace enriched from water by sorption onto CN, C-8, or C-18 and elution with ethyl acetate/toluene. Toluene is added to the ethyl acetate eluent to increase solubility of the polyaromatic hydrocarbons (PAHs) and to enhance elution from the solid phase. The more hydrophobic PAHs, such as pyrene (Fig. 7.11), will recover more efficiently from a more polar reversed phase, such as CN or C-8 due to less strong van der Waals interactions between the analyte and the sorbent. The PAHs may be analyzed by either GC/MS or by HPLC. Soil samples may be processed as in Section 7.10.2 with 90% methanol extraction, followed by dilution with... 

In the microemulsion systems the primary alcohols are frequently considered as cosurfactants, which are usually weakly amphiphilic molecules that help the amphiphilic surfactants to reduce the surface tension of the interface between the immiscible components of the system. In this way they usually enhance and emphasize the internal structure of the system at the colloidal level. Remarkably, the short-chain alcohols, which are sufficiently soluble in water, themselves show surfactant-like behavior in plain binary water mixtures. As was shown by Kahlweit et al. [87], this specific behavior can be observed from the break in the curves of surface tension versus molar fraction of alcohol in water. Similar breaks were observed by Zana et al. [7] in the curves of fluorescence intensity versus molar fraction of alcohol, where changes in the environment polarity are sensed by the pyrene fluorescence probe. Interestingly, with increasing the length of the... 

---