Na. Marley et al., An improved method for the separation of Bi-210 and Po-210 from Pb-210 by using solid-phase extraction disk membranes: Environmental applications, RADIOCH ACT, 85(1-2), 1999, pp. 71-78
An improved method is described for the rapid separation of Bi-210 and Po-2
10 from the parent radionuclide, Pb-210, in environmental samples. After th
e metals were leached from a variety of matrices, they were converted to th
eir anionic chloride complexes by addition of 1 M HCl. These complexes can
be separated by solid-phase extraction with disk extraction membranes impre
gnated with anionic chelating particles. This separation technique takes ad
vantage of the differences in sorption behavior of the chloride complexes t
o strongly basic anion exchange groups. The extraction membranes can then b
e counted directly for Bi-210 and Po-210. If sufficient time is allowed for
ingrowth of the daughter, the concentration of the parent Pb-210 in the or
iginal sample can be determined from the concentration of Bi-210. In additi
on, the ratios of Bi-210/Pb-210 and Po-210/Pb-210 can be obtained by immedi
ate extraction of Bi-210 followed by ingrowth of Bi-210 for a second determ
ination to establish Pb-210 concentration levels. This can be accomplished
easily in order to estimate the residence times of atmospheric aerosols or
aqueous colloidal materials. This new technique avoids the time consuming e
xtraction, precipitation, and electroplating procedures used previously and
eliminates the experimental errors associated with multiple sample manipul
ations.