Solubilization chromatography

Sherma, J. and Hood, L.V.S., Thin-layer solubilization chromatography. I. Phenols, J. Chromatogr.,... 

Riemann, in 1957, described two processes that are called salting-out chromatography and solubilization chromatography. The first one is used with water-soluble compounds like the lower alcohols, esters, ethers, aldehydes and ketones. These are absorbed from concentrated salt solutions, like 4M ammonium sulphate, into cation- or anion-exchange resins and then eluted with aqueous salt solutions of decreasing concentration. The more water-soluble, that is, the more hydrophilic, substances like glycerol and ethyl alcohol are eluted first, and the more hydrophobic, that is, the less water-soluble, substances like amyl alcohol emerge later. 

A combination of salting-out and solubilization chromatography may be employed. Thus separation of acetanilide and the three compounds derived from acetylation of p-aminophenol was successfully carried out by using solutions of potassium phosphate in aqueous methanol. 

Finally, micellar systems are useful in separation methods. Micelles may bind heavy-metal ions, or, through solubilization, organic impurities. Ultrafiltration, chromatography, or solvent extraction may then be used to separate out such contaminants [220-222]. 

The protecting groups are also used to solubilize synthetic intermediates in organic solvents, e.g. methylene chloride. Chromatography is then possible on a larger scale, since silica gel can be used as adsorbent. Six synthetic strategies have been developed (H. Kdster, 1979) ... 

In size exclusion chromatography, the mobile phase must be selected to totally solubilize the sample and eliminate all interactions of the solutes with the... 

Figure 6. High-Performance Size-Exclusion Chromatography of solubilized pectin from the juice. Control is CDTA extracted pectin from parenchyma.

Huot et al. [38] used affinity chromatography to identify and partially purify an amiloride-binding protein with characteristics of the renal brush border Na /H exchanger. The high-affinity amiloride analog A35 (5-A-(3-aminophenyl)amiloride) was coupled to Sepharose CL-4B through a triglycine spacer. Rabbit renal brush border membranes were solubilized with 0.6% Triton X-100, incubated with the... 

In a preliminary report, Ross et al. [40] used affinity chromatography to identify a putative bovine renal brush border Na /H exchanger. Brush border membranes were solubilized with Triton X-100 and chromatographed sequentially over lentil lectin Sepharose 4B and 5-(A-benzyl-iV-ethyl)amiloride coupled to epoxy-activated Sepharose 6B. The eluant contained 178- and 146-kDa proteins that were susceptible to Endo-F. Moreover, the eluants reacted on dot blot immunoassays with antisera to a 20-amino acid peptide of a human Na /H exchanger vide infra). The relationship between these proteins and the 66-kDa protein previously identified by the same investigators using amiloride photolabeling is presently unclear. 

Another important issue to take into account is the low solubility of many of the UV filters, which makes totally necessary to work with unit samples due to the indispensable solubilization step before the analytical determination by high performance liquid chromatography (HPLC). 

Lefkowitz, R. J., Haber, E., and O Hara, D. (1972). Identification of the cardiac beta-adrenergic receptor protein Solubilization and purification by affinity chromatography. Proc. Natl. Acad. Sci. USA 69, 2828-2832. 

Finally, and apart from the importance of micelles in the solubilization of chemical species, mention should also be made of their intervention in the displacement of equilibria and in the modification of kinetics of reactions, as well as in the alteration of physicochemical parameters of certain ions and molecules that affect electrochemical measurements, processes of visible-ultraviolet radiation, fluorescence and phosphorescence emission, flame emission, and plasma spectroscopy, or in processes of extraction, thin-layer chromatography, or high-performance liquid chromatography [2-4, 29-33],... 

Figure 3. Size exclusion chromatography analysis of AP-trapped vs. detergent-solubilized FS2 core complexes.

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