EFFICIENCY OF RADIOCESIUM CONCENTRATION FROM LARGE-VOLUME NATURAL-WATER SAMPLES BY SCAVENGING WITH AMMONIUM MOLYBDOPHOSPHATE

A method for the non-radioactive determination of the recovery of radi ocaesium when concentrated from large volume natural water samples is described. The caesium scavenging efficiency of ammonium molybdophosph ate (AMP) was estimated from the ratio of stable caesium added as a ca rrier (and becoming now an internal yield tracer) and recovered with t he precipitate. Stable caesium was determined by using flame emission spectrometry. Results showed that the scavenging efficiency ranged fro m 91 +/- 3% to 106 +/- 5% with a mean value of 98 +/- 4% and therefore the scavenging procedure may be considered quantitative. Further expe riences showed that the contact time could be reduced to less than fiv e minutes and that the proportion of reagent used in our concentration method was within the appropriate range.