Salting-out procedures

E Allemann, JC Leroux, R Gurny, E Doelker. In vitro extended-release properties of drug loaded poly (dl-lactic acid) nanoparticles produced by a salting-out procedure. Pharm Res 10(12) 1732—1737, 1993. 

All efforts of trying to extract the sodium salt into an organic solvent were unsuccessful, and, thus, a salting out procedure using the common ion effect was used. The product at this stage is in the aqueous phase and addition of 15 g of sodium chloride /100 mL of the reaction mixture, completely precipitates all the coupled sodium salt which is filtered. The filtered crude product is dewatered by washing with isopropyl alcohol or drying under vacuum. The mother liquors... 

Corwen [58] used this method for the analysis of ketones and aldehydes in seawater. Halocarbons were similarly separated from environmental samples by Kaiser and Oliver [59]. There have been many other applications of the technique [60-69]. The major advantage of the headspace method is simplicity in handling the materials. At most, only one chemical, the salt used in the salting-out procedure, needs to be added and in most cases the headspace gas can be injected directly into a gas chromatograph or carbon analyser. On the other hand the concentration of organic materials present is limited by the volume of seawater in the sample bottle. This is very much a batch process. 

Why are salting out procedures often used as an initial purification step following the production of a crude extract by centrifugation ... 

S.A. Miller, D.D. Dykes and H.F. Polesky, A simple salting out procedure for extracting DNA from human nucleated cells, Nucleic Acids Res., 16 (1988) 1215-1219. 

Separation of the signal corresponding to either the bound or free-labeled analyte from that of the total labeled analyte population can be accomplished in two ways. The first involves physical separation of the protein (antibody) bound fraction from the free fraction of labeled analyte. This can be accomplished by a salting-out procedure, using a salt such as ammonium sulfate or a polymer such as polyethylene... 

Mani N, Suh HR, Jun HW. Microencapsulation of a hydrophilic drug into a hydrophobic matrix using a salting-out procedure. II. Effects of adsorbents on microsphere properties. Drug Dev Ind Pharm 2004 30(1) 83-93. 

Schwertner et al. introduced a salting-out procedure, in combination with single extraction using chloroform-isopropanol (95 5). 100 pi plasma samples could be effectively extracted with 2 ml chloroform-isopropanol. Theophylline was derivatized with pentafluoroben-zyl chloride, and 3-isobutyl-l-methylxanthine was used as an internal standard. This standard is similar to theophylline in extractability, derivatization rates, stability and chromatographic properties. Accurate measurements of plasma concentrations ( + 0.22 ug/ml) could be obtained with little or no interference from theophylline metabolites and other coextract-able material. A packed column with 3 OV-17 on Gas Chrom Q and temperature programming from 150°C to 250°C was used in combination with an electron capture detector. 

Although the industry is no longer active in this country, castor oil is still produced in large quantities throughout the world. The toxin, which remains in the castor meal after the oil has been extracted with hexane or carbon tetrachloride, is easily extracted through a simple salting-out procedure.3... 

Weingaertner, Lynn and Hanson (1991) have assessed the recovery of inorganic salts from concentrated aqueous solution in a process that they called extractive crystallization , but in part follows conventional salting-out procedures (sections 8.1.5 and 8.4.6). Enhanced recovery of salt and economical use of solvent are achieved, however, by generating a two-phase change in the filtered mother liquor, by temperature and composition manipulation, and the... 

The salting-out procedure can be considered as a modification of the emulsification/solvent diffusion method. The technique is based on the salting out of water miscible solvents from aqueous solution containing electrolyte salts such as calcium chloride, magnesium acetate or sucrose. Pol)mier and drug are initially... 

Taylor was routinely successful in obtaining pH activity curves with two or more peaks when he used human gastric juice as the source of his enzyme. The location of the peaks, he said, depends in part upon the substrate used. Human plasma protein gave two peaks and egg albumin only one. In addition, Taylor found that some peaks were present in gastric juice or in mucosal extracts from one source and were absent from juice or extracts from another source. Taylor could not separate different pepsins responsible for the peaks by salting-out procedures, and he convinced himself that a single pepsin molecule has two different catalytic sites with optimal activities at different pH levels. ... 

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