METHOD OF PURE CRYSTALLINE D-ARABINOSE PREPARATION

摘要

The solution concerns a method of preparation of pure crystalline D-arabinose by oxidation of sodium D-gluconate, obtained from oxidation of D-glucose. Its principle consists in the fact that 10 to 35 percent by weight of water solution of D-gluconate is enriched at the temperature of 60 degrees C with a solution of sodium hypochlorite in concentration corresponding to 120 to 180 g/l of active chlorine. The pH value of the reaction mixture is maintained within the range of 3.8 to 4.0 by addition of solution of hypochlorite at a speed of 0.5 to 4.0 h-l (in l/ho of solution per l of the reaction mixture), optimally 1.2 h-l, at simultaneous addition of hydrochloric acid and when the addition of hypochlorite is finished, by addition of 10 percent by weight of water solution of sodium hydroxide. Then the obtained solution of D-arabinose is cooled to the room temperature and is subjected to electrodialytic desalination performed in multiplicative discontinuous arrangement with alternate change of the solution in diluate and concentrate branch, where the concentration of salts is reduced below 1 g/l at simultaneous double increase in concentration of arabinose in the solution. Then the desalinated solution is subjected to deionisation on strongly acid cation exchange resin in H<+> cycle and on strongly or medium basic anion exchange resin in OH<-> cycle, in continuous, or eventually discontinuous arrangement and after thickening of the deionised solution the crystallisation of D-arabinose from alcohol is performed.