Synthesis of 6-[18F] fluoro-L-dopa

6-[18F] Fluoro-L-dopa (18FDOPA) is synthesized from the starting material nitro-vera tr-aldehyde via multi-step reaction by nucleophilic displacement combined with chiral catalytic phase-transfer alkylation techniques and the enantiomeric purity of 18FDOPA is determined by HPLC method using a chiral mobile phase and reversed-phase C18 column. The results show that the total time of synthesis is less than 120 min, the total radiochemical yield from potassium [18F] fluoride is about 6.3% with decay-correction and the enantiomeric purity and radiochemical purity are higher than 95% and 99%, respectively. The practical techniques are provided for the radiochemical synthesis and enantiomeric purity determination of 18FDOPA and other [18F] fluoro-L-amino acids