As a good antimicrobial active ingredient, 2,4,4′ trichloro 2′ hydroxydiphenyl ether has been already commercially available since 1970s. For this paper halogenated hydroxydiphenyl ethers were prepared and purified, and their analytical conditions by HPLC were studied. Further purification of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was also studied. The adsorption ability of different decolourants, e.g. alumina and bentonite, for each component in crude product of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was varied. 2,4,4′ trichloro 2′ hydroxydiphenyl ether might be adsorbed by active carbon. The colored impurities might be adsorbed by alumina. The colorless impurities might be adsorbed by bentonite.
