Method for purifying cresidine sulfonic acid by resin extraction

摘要

A method for removing residual cresidine from impure p-cresidine sulfonic acid which impure p-cresidine sulfonic acid contains from above two parts per billion to about 1500 parts per million of cresidine. The method comprises contacting an aqueous solution of the p-cresidine sulfonic acid with a sufficient quantity of particles of a crosslinked lipophilic porous resin for a sufficient time to reduce the concentration of p-cresidine in the cresidine sulfonic acid to less than 2 parts per billion.