High yielding [ 18F]fluorination method by fine control of the base

Abstract

New [ 18F]F-fluorination methods using a minimized amount of precursor has been developed by controlling the base concentration. In the first method, pre-conditioning of the anion exchange cartridge with K 2CO 3 solution or water was carried out. The trapped [ 18F]fluoride on the cartridge was then eluted by KOMs or KOTf solution. [ 18F]F-Fluorination could be performed without additional base. In the second method, the QMA cartridge was preconditioned with KOMs solutions. Trapped [ 18F]fluoride on the QMA was then eluted with KOMs and additional base, such as KOH, K 2CO 3, and KHCO3, was added into the reaction vessel. Method 1 showed a [ 18F]F- incorporation yield of 20.9% for [ 18F]FLT synthesis with 5 mg of precursor. Unlike method 1, a [ 18F]F-incorporation yield of 91.4% was achieved from the same amount of precursor in method 2.