237Np SEPARATION FROM ENVIRONMENTAL MATRICES BY EXTRACTION CHROMATOGRAPHY METHOD

Aliquat-336 anchored on hydrophobized silica gel was used for effective separation of (237)Np from soil matrices and from model solutions. Alpha spectrometry for (237)Np determination was used. The interfering radionuclides present in environmental samples such as (234)U, (232)Th, (231)Pa and (239+240)Pu were removed by separation with nitric acid solutions containing formic acid and ferrous sulfamate as reducing agents. Spiking samples with (238,234)U, (232)Th and (238)Pu were used to check separation effectiveness. A separation yield of (237)Np from soil matrices was checked by measuring of added known amount activity and was found to be about 15%. The yield of separation for model solutions was about 56%. Different parameters of eluant on recovery of (237)Np from column were studied.