Simultaneous measurements of the molar radioactivity, radiochemical purity and chemical impurity in the [11C]choline injection using radio-HPLC with a corona-charged aerosol detector

Abstract [11C]choline has a weak UV absorption chromophore, and it is challenging to detect less than 1 μg/mL choline using radio-HPLC-UV. In this study, we established an analytical procedure of [11C]choline using the radio-HPLC coupled with the corona-charged aerosol detector. As a result, we achieved more than 100 GBq/μmol (over 0.1 μg/mL of choline) of molar radioactivity at the end of synthesis, over 95% of radiochemical purity, and more than 0.1 μg/mL of 2-dimethyoaminoethanol as a chemical impurity.