RADIOCHEMICAL DETERMINATION OF PB-210 IN ENVIRONMENTAL WATER SAMPLES USING CERENKOV COUNTING

A relatively simple method has been developed for the determination of Pb-210 via its beta-emitting daughter, Bi-210. Lead-210 was separated from interfering elements as lead sulphate. The precipitate was disso lved in an alkaline solution of EDTA and the Cerenkov signal produced by the build-up of Bi-210 counted 30 days after storage using tritium channel of a liquid scintillation counter. Cerenkov counting. efficien cy was found to be approximately 20%. A lower limit of detection of 5. 1 mBq/l (based on 3 sigma of the background with 500 minute counting t ime) was achieved. Chemical recoveries in the range of 70-100% were de termined gravimetrically. Interference associated with currently used methods is avoided. Data from both spiked samples and natural samples are presented.