Study on the Purification of Phosphorylation Liquid of L-Ascorbic Acid by Ion-exchange Resin

The phosphorylation liquid of L-ascorbic acid was purified by D301 macroporous weak basic ion-exchange resin.Adsorption kinetic curve and isotherm of sodium L-ascorbate-2-phosphate on D301 ion-exchange resin were measured at room temperature,and the effects of pH value,temperature,concentration of hydrochloric acid were also investigated.Results showed that the equilibrium of adsorption of sodium L-ascorbate-2-phosphate on D301 ion-exchange resin can be reached in 60 mins,the Freundlich model can describe the adsorption well.At room temperature,the reaction mixture was adjusted to pH 1.0 with hydrochloric acid;the solution was then passed through a column packed with D301 ion-exchange resin.The column was developed with 0.02mol/L,0.2 mol/L and 2mol/L hydrochloric acid successively,and 0.2mol/L hydrochloric acid elution was collected.HPLC analysis revealed that the content of L-ascorbic-2-phosphate in the fraction was more than 97 %.