Determination of 210Pb via 210Bi using a hydride generation technique combined with β-spectrometry

A procedure for the determination of 210Pb is presented, which is based upon the β-spectrometric assay (utilizing a liquid-scintillation counter) of 210Bi in radioactive equilibrium. Separation of 210Bi from the sample matrix as well as from other β-emitters is achieved quickly, simply and selectively using a purge and trap technique based upon the generation and subsequent absorption of BiH3 on a prepared filter paper. Advantages of this method include: 1. radioactive equilibrium between 210Pb and 210Bi is relatively quickly attained; 2. the external background signal in liquid-scintillation counting is very low; 3. no quenching corrections are necessary, as the sample matrix is invariant; and 4. because of the high counting efficiency, only short measuring times are required. (orig.)