Comparison between Different Techniques in Purification of 18O Enriched Water after Cyclotron Irradiation

Abstract

AbstractIn the synthesis of 18F-FDG by nucleophilic substitution method, 18O-H2O is usually used as target water. The high cost of virgin 18O-H2O enriched water pointed to recycle process after the first irradiation for the production of radiopharmaceuticals. The irradiated 18O-H2O was contaminated by both organic substances (ethanol, acetonitrile, etc.) and inorganic ions (Cd2+, Na+, K+, Cl-, etc). In our study different techniques (ozonolysis, UV, distillation and resin) were used to minimize the concentration of both organic substances and inorganic ions and evaluate the effectiveness of resin as method for the purification. The concentration of the TOC was decreased from 705 (mg/L) for the irradiated18O water to 12.36 (mg/L) and 4.8 (mg/L) by using UV and ozonolysis respectively. While the concentration of metal ions decreased and the conductivity decreased from 487 μ Si/cm for the irradiated 18O water to 51.9 μ Si/cm when regenerated resin was used and to 20.8 μ Si/cm by distillation.