[en] A linear polyether, 1,13-Bis-[8-quinolyl]-1,4,7,10,13-pentaoxatridecane, was investigated as a possible extraction agent for the trivalent actinides. The normally lipophilic substance was found to protonate when contacted with aqueous phases of high hydrogen ion concentration. Several commercially available cryptands, 222BB and 222D, were also studied as possible extraction agents. The protonation reactions of these compounds lead to their almost complete extraction into the aqueous phase at pH < 2. The characteristics of these compounds are similar to the tertiary amine extraction agents now well-characterized and thus the macrocyclic compounds hold further promise as extraction agents