Fast and Easy Drying Method for the Preparation of Activated [18F]Fluoride Using Polymer Cartridge

摘要

An efficient nucleophilic [18F]fluorination has been studied to reduce byproducts and preparation time. Instead of conventional aqueous solution of K2CO3-K222, several organic solution containing inert organic salts were used to release [18F]fluoride ion and anion bases captured in the polymer cartridge, concluding that methanol solution is the best choice. Comparing to azeotropic drying process, one min was sufficient to remove methanol completely, resulting in about 10% radioactivity saving by reducing drying time. The polymer cartridge, Chromafix® (PS-HCO3) was pretreated with several anion bases to displace pre-loaded bicarbonate base. Phosphate bases showed better results than carbonate bases in terms of lower basicity. tert-Butanol solvent used as a reaction media played another critical role in nucleophilic [18F]fluorination by suppressing eliminated side product. Consequent [18F]fluorination under the present condition afforded fast preparation of reaction solution and high radiochemical yields (98% radio-TLC, 84% RCY) with 94% of precursor remained.