The measurement of99Tc in seaweed: Results from an international intercomparison exercise

Five samples of brown seaweed, collected from a variety of sites around northern Europe, were distributed to 14 laboratories for analysis of99Tc. Consistency in results between laboratories was found to be strongly correlated with concentration levels, with results diverging markedly at99Tc concentrations below 100 Bq·kg−1. No systematic differences were apparent between radiometric and mass based techniques but the results do suggest that the use of Re as a tracer may lead to an underestimation of99Tc levels.