Simple and efficient automated radiosynthesis of 2‐18F‐fluoropropionic acid using solid‐phase extraction cartridges purification

2‐18F‐Fluoropropionic acid (18F‐FPA), a fluorinated analog of 11C‐acetate, shows great potential for positron emission tomography (PET) imaging of prostate cancer. The present study reports a simple automated synthesis using cartridges purification, which affords 18F‐FPA suitable for human use. Automated synthesis of 18F‐FPA was performed using two‐step one‐pot synthesis procedure, consisting of [18F]fluorination of methyl‐2‐bromopropionate, hydrolysis with sodium hydroxide, and purification with a series of commercial solid‐phase extraction cartridges instead of a high‐performance liquid chromatography system. Automated synthesis of 18F‐FPA was also carried out via the on‐column hydrolysis on the HLB cartridges, using a similar procedure to the automated synthesis of 18F‐fluoro‐2‐deoxy‐ d‐glucose (18F‐FDG). Using one‐pot procedures on the commercial modified PET‐MF‐2V‐IT‐I synthesizer, the final 18F‐FPA solution could be obtained with high uncorrected radiochemical yields (>35%) and radiochemical purity (>95%). For the on‐column hydrolysis procedure, the uncorrected radiochemical yield of 18F‐FPA was 46 ± 7% (n = 5, based on [18F]fluoride) within 36 min and the radiochemical purity was above 95% with the specific activity of 40 GBq/µmol. Automated synthesis of 18F‐FPA by on‐column hydrolysis procedure is similar to the 18F‐FDG synthesis, and it can easily be applied to the automated synthesis of 18F‐FPA on the commercial 18F‐FDG synthesizer. Copyright © 2012 John Wiley & Sons, Ltd.