Recycling of 18O enriched water used in 18F cyclotron production

Highlights: • Simple method for recycling of irradiated ¹⁸O-enriched water with optimized procedure for reducing the radiation burden by eliminating all radioactive contaminants as a first step in the process. • Organic compounds, radioisotopes and trace metals are eliminated by high-yield processes included in this method such as co-precipitation, co-crystallization and distillation. • The method demonstrates effective purification ability in a wide range of concentrations of organic solvent impurities from ppm to percentage. • A new method for purification of previously irradiated enriched water for volumes less than 100 ml> is developed. • The method ensures elimination of radioisotopes (99.7% ± 0.1%), organic compounds (99.5% ± 0.1%) and trace metals (99.8% ± 0.1%) with special attention on radiation safety and generated radioactive waste. - Abstract: A simple, effective, easy-handling and reliable method for recycling of [¹⁸O]H₂O from fluorine-18 production, was developed based on co-precipitation, co-crystallization and distillation. Preliminary experiments with normal H₂O were used to determine the optimal purification conditions, which were tested for purification of used [¹⁸O]H₂O from a scientific and commercial ¹⁸F-production facility. The obtained recycled [¹⁸O]H₂O had comparable quality to commercially available ¹⁸O enriched water. The loss of weight for enriched water was about only 7% and losses of ¹⁸O enrichment about 1.3% ± 0.2%. The method ensures elimination of radioisotopes (99.7% ± 0.1%), organic compounds (99.5% ± 0.1%) and trace metals (99.8% ± 0.1%) with special attention on radiation safety with dosimetry control checks and in total 1000 times mass reduction of the initial radioactive waste.