analytical standard Synonym(s): 2,2'-Dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonic acid disodium salt; Disodium 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone; Disodium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonate; Disodium...