Extraction biochemical separation

Although the general principles of separation processes are applicable widely across the process industries, more specialised techniques are now being developed. Reference is made in Chapter 13 to the use of supercritical fluids, such as carbon dioxide, for the extraction of components from naturally produced materials in the food industry, and to the applications of aqueous two-phase systems of low interfacial tensions for the separation of the products from bioreactors, many of which will be degraded by the action of harsh organic solvents. In many cases, biochemical separations may involve separation processes of up to ten stages, possibly with each utilising a different technique. Very often, differences in both physical and chemical properties are utilised. Frequently... 

Sequential extractions with various solvents have been used to isolate discrete biochemical fractions and to investigate the biochemical associations of Se in marine animals and seaweeds [30, 32, 37]. Figure 20.4 presents an overall flow chart of extraction and separation procedures that can be used to isolate, separate,... 

U. Karsten, D. N. Thomas, G. Weykam, C. Daniel, and G. O. Kirst, A simple and rapid method for extraction and separation of low molecular weight carbohydrates using high-performance liquid chromatography, Plant Physiol. Biochem., 29 (1991) 373-378. 

When the distribution ratio is not highly favorable, it is still possible to obtain a quantitative and selective separation through the use of a countercurrent liquid extraction approach. Although such approaches are no longer practical, having largely been supplanted by instrumental techniques such as preparative HPLC and continuous solvent extraction, countercurrent separations are conceptually useful. These approaches can be applied to preliminary separation of complex mixtures or in the isolation of compounds that do not perform well in LC because of undesirable interaction with the stationary phase (irreversible adsorption, denaturation, etc.). For these reasons, most applications of countercurrent separations involve the isolation of natural or biochemical products from plant or animal extracts. As will be described below, countercurrent extractions form the theoretical basis for LLE cartridges. 

C7. Chen, Y., Isherwood, F. A., and Mapson, L. W., Quantitative estimation of ascorbic acid and related substances in biological extracts by separation on paper chromatogram. Biochem. J. 65, 821-823 (1953). 

Cascaval D, Oniscu C, Galaction A-I. Selective separation of amino acids by reactive extraction. Biochem. Eng. J. 2001 7(3) 171-176. 

Biopolymer Extraction. Research interests involving new techniques for separation of biochemicals from fermentation broth and cell culture media have increased as biotechnology has grown. Most separation methods are limited to small-scale appHcations but recendy solvent extraction has been studied as a potential technique for continuous and large-scale production and the use of two-phase aqueous systems has received increasing attention (259). A range of enzymes have favorable partition properties in a system based on a PGE—dextran—salt solution (97) ... 

A large number of radiometric techniques have been developed for Pu analysis on tracer, biochemical, and environmental samples (119,120). In general the a-particles of most Pu isotopes are detected by gas-proportional, surface-barrier, or scintillation detectors. When the level of Pu is lower than 10 g/g sample, radiometric techniques must be enhanced by preliminary extraction of the Pu to concentrate the Pu and separate it from other radioisotopes (121,122). Alternatively, fission—fragment track detection can detect Pu at a level of 10 g/g sample or better (123). Chemical concentration of Pu from urine, neutron irradiation in a research reactor, followed by fission track detection, can achieve a sensitivity for Pu of better than 1 mBq/L (4 X 10 g/g sample) (124). 

Corticotropin [92307-52-3] polypeptide Mr -4697. Extract separated by ion-exchange on CM-cellulose, desalted, evapd and lyophilised. Then run on gel filtration (Sephadex G-50) [Lande et al. Biochemical Preparations 13 45 1971 Esch et al. Biochem Biophys Res Commun 122 899 1984],... 

Lipoteichoic acids (from gram-positive bacteria) [56411-57-5J. Extracted by hot phenol/water from disrupted cells. Nucleic acids that were also extracted were removed by treatment with nucleases. Nucleic resistant acids, proteins, polysaccharides and teichoic acids were separated from lipoteichoic acids by anion-exchange chromatography on DEAE-Sephacel or by hydrophobic interaction on octyl-Sepharose [Fischer et al. Ear J Biochem 133 523 1983]. 

Watanabe, T. et al., Separation and determination of yellow and red Safflower pigments in food by capillary electrophoresis, Biosci. Biotech. Biochem., 61, 1179, 1997. Fekrat, H., The application of crocin and saffron ethanol-extractable components in formulation of health care and beauty care products. Proceedings of International Symposium on Saffron Biology and Biotechnology, Fernandez, J.A. and Abdullaev, R, Eds., Albacete, Spain, 2004, p. 650. 

Weaver, L. (1956). Separation of rare earths by liquid-liquid extraction, page 50 in Rare Earths in Biochemical and Medical Research A Conference Sponsored by the Medical Division, Oak Ridge Institute of Nuclear Studies, October 1955, Report No. ORINS-12, Kyker, G. C. and Anderson, E. B., Eds. (Office of Technical Services, Washington). 

Fungi. I. Metabolic Products otLentinus lepideus. Biochem. J. 34. 82 (1940). 7a. Black, R. A., A. A. Rosen and S. L. Adams The Chromatographic Separation of Hardwood Extractive Components Giving Color Reactions with Phloroglucinol. J. Amer. chem. Soc. 75, 5344 (1953). 

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