Study on Purification of Used Oxygen-18 Water in Preparation of Positron with Cyclotron

A novel method for recovering used O-18 water in [¹⁸F]FDG synthesis was developed. Base on the properties of anhydrous salt and salt with crystal water, anhydrous potassium fluoride and sodium sulfide were used to accomplish purification of used O-18 water. With the self-assembled instruments, the contaminants of methanol, ethanol and acetonitrile were decreased from 103 ppm, 496 ppm, 571 ppm to less than 32 ppm, 63 ppm, 50 ppm for methanol, ethanol and acetonitrile, respectively. The no-oxygen salt avoided to induce new oxygen-16 contaminants. Recovered O-18 water was used in radiotracer synthesis and gave similar radiochemical yield to new O-18 water.