“…The radiochemical procedure described above was developed over more than 10 years, and we profited much from the experience we gained while completing many projects on Pu, Am and Sr determination in animal bones (Gaca et al, 2005;Kitowski et al, 2008;Mietelski et al, 2000Mietelski et al, , 2001aMietelski et al, , 2001bMietelski et al, , 2006Mietelski et al, , 2008aMietelski et al, , 2008b. Due to worldwide shortage of animal bones reference materials (RM) in many of our projects, the soil matrix RMs were applied instead.…”