Tritium and 14C in Tree Rings of the Last Three Decades

Abstract

Tree rings spanning the past three decades were collected from Picea spp trees grown in Matra, northern Hungary. Cellulose was prepared from the wood and samples were separately combusted for tritium and 14C analyses. Methane was synthesized from CO2 obtained by sample combustion via catalytic reaction with tritium-free hydrogen. 14C activity was measured by proportional counter. The exchangeable tritium was removed from cellulose samples used for tritium analysis. Water samples produced by combustion were measured by liquid scintillation counting. The distribution of tritium and 14C activities in tree rings are shown for years 1956-1986. Results are compared with published data on global-scale distribution of 14C and HTO. A comparison of tritium activity in precipitation and wine samples from the same region is presented.