METHOD OF EXTRACTING HISTIDINE FROM AQUEOUS SOLUTIONS Russian patent published in 2015 - IPC C07D233/64 B01D11/00 

FIELD: chemistry.

SUBSTANCE: method includes preparing an aqueous salt solution of histidine by dissolution thereof in a saturated solution of a salting-out agent, extraction and analysis of the equilibrium aqueous phase. The method is characterised by that histidine extraction is carried out with a solution of a poly-N-vinylcaprolactam-N-vinylformamide copolymer in distilled water with concentration of 1.15-1.20 g/cm³ for 7-10 minutes. The volume ratio of the aqueous salt solution of histidine to the extractant is 5:2, and the salting-out agent used is ammonium sulphate solution. Further, the aqueous salt solution is separated from the organic phase, followed by measuring optical density of the aqueous salt solution, using a calibration curve to determine concentration of histidine in the analysed aqueous solution and calculating the distribution coefficient (D) and extraction ratio (R, %) of histidine using formulae given below, where c_o and c_a denote concentration of histidine in the organic and aqueous phases, f is the volume ratio of equilibrium aqueous and organic phases.

EFFECT: method increases the extraction ratio of histidine from aqueous solutions.

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