On the determination of 99Tc in environmental waters.
In this paper we propose a search for 99Tc in flocs from water treatment plants. We show that preconcentration of 99Tc from environmental waters is a very advantageous method because of the high volumes involved. A radiochemical method is adapted in these kinds of samples, and 99Tc is identified in them by a previously published method. A typical value found is 0.56 +/- 0.26 mBq/g, where 1 g dry floc should be related to many liters of water.