Anion-exchange resin, chromatography

It is appropriate to refer here to the development of non-suppressed ion chromatography. A simple chromatographic system for anions which uses a conductivity detector but requires no suppressor column has been described by Fritz and co-workers.28 The anions are separated on a column of macroporous anion exchange resin which has a very low capacity, so that only a very dilute solution (ca 10 4M) of an aromatic organic acid salt (e.g. sodium phthalate) is required as the eluant. The low conductance of the eluant eliminates the need for a suppressor column and the separated anions can be detected by electrical conductance. In general, however, non-suppressed ion chromatography is an order of magnitude less sensitive than the suppressed mode. 

Tanaka, K., Ishizuka, T., and Sunahara, H., Chromatography of aliphatic amines on an anion-exchange resin, ]. Chromatogr., 172, 484, 1979. 

Palu, M. and Samuelson, O., Influence of aromatic compounds in sugar chromatography on anion-exchange resins, Talanta, 24, 264, 1977. 

Dowex monosphere 550A (OH) anion-exchange resin (60 mL) equipment for ion-exchange chromatography rotary evaporator. 

Material. 3 X crystallized, dialyzed and lyophilized Grade 1 Hen Egg White Lysoz3mie was obtained from Sigma Chemical Company, and used without further purification. Purity of the protein was verified by both gel electrophoresis on acrylamide and chromatography on a column packed with anion exchange resin (Cl form) Sephadex DEAE. The sample showed a single peak in these analyses. 

Elemental composition P 38.73%, H 1.26%, O 60.01%. The compound may be identified by physical properties alone. It may be distinguished from ortho and pyrophosphates by its reaction with a neutral silver nitrate solution. Metaphosphate forms a white crystalline precipitate with AgNOs, while P04 produces a yellow precipitate and P20 yields a white gelatinous precipitate. Alternatively, metaphosphate solution acidified with acetic acid forms a white precipitate when treated with a solution of albumen. The other two phosphate ions do not respond to this test. A cold dilute aqueous solution may be analyzed for HPO3 by ion chromatography using a styrene divinylbenzene-based low-capacity anion-exchange resin. 

Anions may be measured best by ion chromatography, using appropriate anion exchange resin columns that are available commercially. Salts may be diluted for such measurements. Ion-selective electrode methods also yield satisfactory results at trace concentrations. Numerous colorimetric methods are reported in literature. They are susceptible to erroneous results when impurities are present. Many titration methods are available in analytical chemistry. They may be applied successfully to measure certain anions, oxidizing and reducing substances, acids, and bases. 

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