The use of solid phase extraction (SPE) disks was studied for the quantification of selected radionuclides in aqueous solutions. The extraction of four radionuclides using six types (two commerical, four test materials) of 3M EmporeTM RAD disks was studied. The radionuclides studied were: technetium-99 (two types of disks), cesium-137 (two types), strontium-90 (one type), plutonium-238 (one type). Extractions were tested from DI water, river water and seawater. Extraction efficiency, kinetics (flow rate past the disk), capacity, and potential interferences were studied as well as quantification methods.