METHOD FOR ION-EXCHANGE SEPARATION OF METHIONINE AND GLYCINE Russian patent published in 2011 - IPC C07C227/40 C07C319/28 G01N30/02 G01N30/96 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for ion-exchange separation of methionine and glycine and can be used in biochemistry, pharmaceutical and food industry. The method involves separation of methionine and glycine in two steps. At the first step amino acids undergo sorption with enrichment of the sorbent phase with glycine, and the solution at the output enriched with methionine. For this purpose, polyampholyte Purolite S950 in H-form is prepared. The mixture of two aliphatic amino acids undergoes sorption in a countercurrent column with a fixed sorbent layer. For this purpose, a solution containing a mixture of glycine and methionine is fed from below and glycine is undergoes sorption on polyampholyte Purolite S950. Methionine, appears at the output, the aqueous solution of which is sorbed in a receiver at the output of the column and after a certain time - the amino acids. Sorption is stopped. During sorption, samples are collected at defined time intervals. Total concentration of amino acids is controlled using an iodimetric method, and concentration of methionine is controlled using a spectrophotometric method, while glycine concentration is controlled based on concentration difference: between total concentration and methionine concentration. The degree of separation of the initial solution is equal to 60%. At the second step, glycine is eluted with hydrochloric acid solution at pH 1.2 from the sorbent while feeding glycine-containing eluate from the top, and sorbed in the receiver. Concentration of glycine is equal to 70%. After desorption of glycine, the mixture of amino acids undergoes complete desorption. Polyampholyte takes the initial shape and is ready for operation. Samples are collected at defined time intervals and each sample is analysed using iodometric and spectrophotometric methods. For complete separation of glycine from methionine, the two-step process of separating the mixture of amino acids obtained at the output of the column is repeated.

EFFECT: method enables efficient separation of methionine and glycine by combining sorption and desorption processes while excluding the sorbent regeneration step, and reduce the volume of wash water without using considerable amount of auxiliary reactants.

2 dwg, 2 tbl, 1 ex