GB881855A - Elution of organic substances from ion-exchange resins - Google Patents

Abstract

Heparin is recovered from a solution containing it by adsorption upon an ion-exchange resin and elution with a mixture of a watermiscible organic solvent, water and a salt. Typical solvents are methanol, ethanol, isopropanol, ethylene glycol, dioxane, acetone, ethyl acetate and dimethylformamide. A preferred elutrient is a mixture of water, methanol and ammonium chloride. Sufficient water must be present in the solvent to permit ionization of the salt and its proportion may be as low as 1% or as high as 70%.ALSO:A process for the recovery of an ionic organic substance from a solution containing it by adsorbing the substance upon an ion-exchange resin and eluting it from the ion-exchange resin, characterised in that the elutrient is a mixture of a water-miscible organic solvent, water and a salt which is soluble in said solvent-water mixture, the elutrient also being a solvent for the ionic organic substance. The salts must be ionic and may be inorganic or organic, e.g. acetate, propionate, butyrate, benzoate, chloracetate and amine salts. Sufficient water must be present in the solvent to permit ionization of the salt and it may be as low as 1% or as high as 70% water. Typical solvents are methanol, ethanol, isopropanol, ethylene glycol, dioxane, acetone, ethyl acetate and dimethylformamide. A preferred elutrient is a mixture of water, methanol and ammonium chloride. The ionic organic substances include both weak and strong organic acids and bases. Specified organic compounds are (a) the antibiotics penicillin, novobiocin, eulicin and cytovirin; (b) the vitamin p B2 phosphate, vitamin K phosphate and vitamin B1; (c) the alkaloids morphine, quinine, yohimbine and resperine; (d) the acids gibberellic acid, desoxycholic acid, folic acid, palmitic acid, nicotinic acid and ascorbic acid.ALSO:Methyl orange is recovered from a solution containing it by absorption upon an ion-exchange resin and elution with a mixture of a water-miscible organic solvent, water, and a salt. Sufficient water must be present in the solvent to permit ionization of the salt and the proportion of water may be 1%-70%. The salt may be that of an organic or inorganic acid. In an example a solution of methyl orange in ammoniacal water is passed through a column containing a strongly basic styrene-divinylbenzene resin or a weakly basic aminated polystyrene resin. The resin is then eluted with a methanol/ammonium chloride aqueous solution.ALSO:Zinc insulin is recovered from an aqueous hydrochloric acid solution thereof by adsorbing it upon an ion exchange resin and eluting it therefrom with a mixture of a water-miscible organic solvent, water and a salt which is soluble in said water solvent mixture. In the example, the zinc insulin is adsorbed upon Dowex 50-XI resin and eluted with an aqueous solution containing 70% ethanol and 3.5% sodium chloride.