Extraction behavior of137Cs was studied from nitric acid medium using dibenzo 18 crown 6 (DB18C6), 4,4'(5')di-acetylbenzo 18 crown 6 (DAB18C6), 4,
4'(5')di-hexanoylbenzo 18 crown 6 (DHB18C6), 4,4'(5')di-nonanoylbenzo 18 crown 6 (DNB18C6) and 4,4'(5')di-t-butylbenzo 18
crown 6 (DTBB18C6) in nitrobenzene medium. The stoichiometry of the species extracted with dibenzo 18 crown 6 (L) conformed
to ML+. NO3− TheDCs values were found not to be affected by the presence of aluminium nitrate in the aqueous phase. The separation behavior of
fission products obtained from an irradiated natural uranium target was also studied. Presence of 0.004M phosphotungstic acid
found to enhance theDCs values at lower acidities.