Radiochemical determination of lead-210 in uranium ores and air dusts

An improved procedure is described by which cellulose, glass fiber, and polystyrene filters can be wet-ashed and siliceous samples dissolved completely without loss of lead by either volatilization or spontaneous reduction to metal that occurs with dry ashing and/or treatment in platinum containers. The solution of bismuth-210 used to calibrate the ..beta.. counter is prepared by chemical separation from a solution of lead-210 which is much more convenient and results in a product of higher specific activity than one prepared by neutron activation of stable bismuth. After separation from the samples by conventional chemical procedures, the bismuth-210 is precipitated on barium sulfate for ..beta.. counting which is more convenient and gives a more uniform and reproducible deposit than is obtained by most other means.