Biphenyl solubility

Now consider the case depicted in figure 3.20c, an isotherm at the UCEP temperature (see figure 3.19). At the UCEP pressure there is a vapor-liquid critical point in the presence of solid. This requires the solid-liquid equilibrium curve to intersect the liquid-gas envelope precisely at the binary liquid-gas critical point and, hence, exhibit a negative horizontal inflection, i.e., (dPldx)T = 0. Notice that the vapor-liquid envelope has not shrunk to a point, as it did at the naphthalene-ethylene UCEP. The solid curve shown in figure 3.20d is the solubility isotherm obtained if a flow-through apparatus is used and only the solubility in the SCF phase is determined. This solid curve has the characteristics of the 55°C biphenyl-carbon dioxide isotherm shown in figure 3.17. So the 55°C isotherm represents liquid biphenyl solubilities at pressures below 475 bar and solid biphenyl solubilities at pressures above 475 bar. 

Naphthalene, CioHs, colourless solid, m.p. 80°, insoluble in water, soluble in alcohol, characteristic odour. Anthracene, CjH4 C2H2 CjH4, m.p. 216°, white crystals when pure, with a faint blue fluorescence, but often very pale yellow crystals insoluble in water, slightly soluble in alcohol. Phenanthrene, m.p. 98°, and biphenyl, m.p. 69°, are white solids. 

Extraction, employs a liquid solvent to remove certain compounds from another liquid using the preferential solubility of these solutes in the MSA. For instance, wash oils can be used to remove phenols mid polychlorinated biphenyls (PCBs) from die aqueous wastes of synthetic-fuel plants and chlorinated hydrocarbons from organic wastewater. 

Weil LG, Dure G, Quentin KL. 1974. [Solubility in water of insecticide chlorinated hydrocarbons and polychlorinated biphenyls in view of water pollution.] Z Wasser Abwasser Forsch 7 169-175. (German)... 

Golbeck JH, SA Albaugh, R Radmer (1983) Metabolism of biphenyl by Aspergillus toxicarius induction of hydroxylating activity and accumulation of water-soluble conjugates. J Bacteriol 156 49-57. 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

Griffin, R.A. Chian, E.S.K. "Attenuation of Water Soluble Polychlorinated Biphenyls by Earth Materials EPA Publication, 600/2-80-027, 1980. 

Fig. 5. Relationship between the distribution (partition) coefficient on dimethyl dihydrogenated tallow montmorillonite for a range of non-ionic organic pollutants and their corresponding solubility in water. BHC is benzene hexachloride, the y-isomer of which is known as lindane aroclor 1232 and aroclor 1252 denote mixtures of polychlorinated biphenyls containing about 32 and 52% chlorine, respectively. After Beall (2003).

The van t Hoff equation also has been used to describe the temperature effect on Henry s law constant over a narrow range for volatile chlorinated organic chemicals (Ashworth et al. 1988) and chlorobenzenes, polychlorinated biphenyls, and polynuclear aromatic hydrocarbons (ten Hulscher et al. 1992, Alaee et al. 1996). Henry s law constant can be expressed as the ratio of vapor pressure to solubility, i.e., pic or plx for dilute solutions. Note that since H is expressed using a volumetric concentration, it is also affected by the effect of temperature on liquid density whereas kH using mole fraction is unaffected by liquid density (Tucker and Christian 1979), thus... 

Bruggeman, W. A., van der Steen, J., Hutzinger, O. (1982) Reversed-phase thin-layer chromatography of polynuclear aromatic hydrocarbons and chlorinated biphenyls. Relationship with hydrophobicity as measured by aqueous solubility and octanol-water partition coefficient. J. Chromatogr. 238, 335-346. 

Doucette, W. J., Andren, A. W. (1988a) Aqueous solubility of selected biphenyl, furan, and dioxin congeners. Chemosphere 17, 243-252. 

Dunnivant, F. M., Elzerman, A. W., Jurs, P. C., Hansen, M. N. (1992) Quantitative structure-property relationships for aqueous solubilities and Henry s law constants of polychlorinated biphenyls. Environ. Sci. Technol. 26, 1567-1573. 

Kamlet, M. J., Doherty, R. M., Carr, P. W., Mackay, D., Abraham, M. H., Taft, R. W. (1988) Linear solvation energy relationships. 44. Parameter estimation rules that allow accurate prediction of octanol/water partition coefficients and other solubility and toxicity properties of polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Environ. Sci. Technol. 22, 503-509. 

Miller, M. M., Ghodbane, S., Wasik, S. R, Tewari, Y. B., Martire, D. E. (1984) Aqueous solubilities, octanol/water partition coefficients and entropies of melting of chlorinated benzenes and biphenyls. J. Chem. Eng. Data 29, 184-190. 

Shiu, W.-Y., Mackay, D. (1986) A critical review of aqueous solubilities, vapor pressures, Henry s law constants, and octanol-water partition coefficients of the polychlorinated biphenyls. J. Phys. Chem. Ref. Data 15, 911-929. 

Reported aqueous solubilities of biphenyl at various temperatures... 

FIGURE 4.1.1.13.1 Logarithm of mole fraction solubility (In x) versus reciprocal temperature for biphenyl. 

Chou, S.F.J., Griffin, R.A. (1987) Solubility and soil mobility of polychlorinated biphenyls. In PCBs and the Environment. Waid, J.S., Editor, CRC Press, Inc., Boca Raton, Florida, pp. 101-120. 

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