TRACE-ELEMENT DETERMINATION IN POLYMERS BY NEUTRON-ACTIVATION

Neutron activation has been used to determine the concentrations of trace elements in polyethylene. A procedure has been optimized which involves three irradiations with a SLOWPOKE nuclear reactor and four counts with a gamma-ray spectrometer. Phosphorus is determined with beta-ray spectrometry. The detection limits, most of which are below one ppm, have been determined for 42 elements. The merits of the method are discussed in terms of sensitivity, accuracy, ease of use, interferences, and freedom from contamination.