Weight solubilization ratio

The solubihty potential of a surfactant can be represented using the weight solubilization ratio (WSR). 

The capacity of a surfactant to solubilize a particular HOC can be described by the weight solubilization ratio (WSR), ctefined as the mass of HOC solubilized per mass of surfactant in nucellar form. The WSR corresponds to the slope of the linear portion of flie solubility curve above the CMC, and may be expressed as ... 

Figure 14.4 Gel image of proteins extracted from a mixed carbonic anhydrase lysozyme tissue surrogate. Lane M, molecular weight marker lane 1, a 1 2 mol ratio mixture of native, non-formalin-treated carbonic anhydrase and lysozyme lane 2, mixed surrogate with 1 2 mol ratio carbonic anhydrase lysozyme, solubilized and retrieved in 20mM Tris-HCl, pH 4.0, with 2% SDS lane 3, mixed surrogate with 1 2 mol ratio carbonic anhydrase lysozyme, solubilized and retrieved in 20mM Tris-HCl, pH 6.0, with 2% SDS. Protein bands corresponding to lysozyme monomer (a), carbonic anhydrase monomer (b), and the putative lysozyme-carbonic anhydrase heterodimer (c) are indicated. For more detail, see Reference 25.

The water slurry of SP-300 was acidified to pH 2 with 10% HCL to obtain two forms of precipitates one was lumpy and the other was powder-like. After separation from the solution, each form of precipitate was dried. The former was designated as fraction I and the latter, fraction J. The solid product from SP-300 was acidified, separated from the solution and dried. Then the product was extracted with pyridine at room temperature with a solvent/sample ratio of 10. The soluble portion was called fraction K. Thus SP-300 was divided into four fractions fractions I, J, K, and Pyridine-Insoluble. Likewise, SP-320 was divided into four fractions fractions I Jf, K, and Pyridine-Insoluble. Figure 1 summarizes the procedures used in the preparation of all CDL products. Elemental compositions, molecular weight, nuclear magnetic resonance and infrared spectra were obtained for each major fraction. Details of the preparation of specific fractions of HVL-P and solubilization products and analyses can be found elsewhere (13,14). 

NADPH-cytochrome P-460 reductase is composed of a single polypeptide chain of 70,000-80,000 molecular weight 369, 371, 373, 374) associated with one molecule of FAD and one molecule of FMN 370, 371, 373, 378, 379). These results apply to the enzyme whether solubilized by proteolytic digestion or by detergent extraction. The minimum molecular weight based on the flavin content is somewhat higher, 87,000 (373), possibly indicative of the flavin lability observed upon irradiation in ammonium sulfate 380). The detergent-solubilized reductase has a lower flavin content, 0.64 and 0.79 moles of FMN and FAD per 79,000 g of enzyme 371). The absorbance ratio, 275 nm 455 nm of 6.5, indicates a relatively low content of aromatic amino acids 373, 374) The extinction of the flavins at 455 nm is 10.7 mM cm" (373). 

The enhanced water solubihty, on the other hand, is caused by the existence of inverse micelles. The maximum size of these to allow maximum water solubilization depends critically on the alcohol/soap ratio in Figure lb maximum water solubility is obtained at a weight ratio of 5 2. 

Figure 2. Deuterium NMR spectra of n-hexadecane-dg solubilized in a lamellar dispersion of C12E4/H2O as a function of oil content (the numbers are weight fraction of oil) at a fixed soap.water ratio (60 40 W/W).

Let us now turn to the discussion of main trends in solubilization process using on the results of studies carried out by Z.N. Markina [19]. Let us use the direct solubilization of hydrocarbons and alcohols in aqueous surfactant solutions as an example. It is well known that the solubility of hydrocarbons in water is very small, e.g. for octane it is about 0.0015% by weight. At the same time, one may prepare 2% solution of octane in 10% sodium oleate solution, i.e., the effective solubility of this hydrocarbon increases by more than three orders of magnitude. Solubilization can be described quantitatively by characteristic referred to as the relative solubilization, s, given by the ratio of the number of moles of solubilized... 

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