A new radiochemical group separation method using APDC reagent in the extraction procedure has been developed. The method
has been applied to the radiochemical separation for activated biological samples and also to the preconcentration technique
for sea water samples. The transition elements are extracted into chloroform phase from the pH 3.0 aqueous phase and only
manganese is subsequently extracted from the pH 7.0 aqueous phase. The validity of the method is demonstrated by analyzing
the NBS standard reference materials. In the specimens preconcentrated from the sea water samples adjusted pH to 5.5, vanadium,
manganese, copper and zinc can be determined.