Effect of UV-irradiation on the preparation of tritium-labeled polyethylene

Polyethylene (PE) was labeled with tritium by exposure to ultraviolet (UV) lights in tritium gas. Without UV irradiation the exchange rate of specific activity of tritium in high density polyethylene (HDPE) was 2.1 x 10 8 Bq/g atm h. The specific activity in low density polyethylene (LDPE) was slightly higher than that in HDPE. The irradiation with UV enhanced the tritium labeling to an extent of 10-fold. LDPE containing aromatic additive was labeled more effectively by UV irradiation.