Being the refinement mannered null ionicity

摘要

PROBLEM TO BE SOLVED: To provide a method for purifying an ionic high-molecular compound comprising efficiently removing low-molecular impurities from an aqueous solution containing the ionic high-molecular compound and concurrently preventing the aqueous solution from discoloration or the like. ;SOLUTION: This method for purifying an ionic high-molecular compound comprises contacting an aqueous solution containing the ionic high-molecular compound and low-molecular impurities with active carbon ≤0.1 wt.% in acid- soluble iron content to remove the low-molecular impurities. Another version of this method comprises contacting an aqueous solution containing the ionic high-molecular compound and low-molecular impurities with active carbon under such conditions as to be ≥3 in the pH of the aqueous solution after subjected to the contact treatment to remove the low-molecular impurities.;COPYRIGHT: (C)2001,JPO