Efficient HPLC separation of [11C]β-CFT or [11C]β-CIT from an N-desmethyl precursor on a semipreparative reversed phase ODS column

HPLC separation of either [11C]β-CFT or [11C]β-CIT from the N-desmethyl precursor greatly depended on the ODS column used and the pH of the phosphate buffer in the mobile phase. The separation was accomplished on the semipreparative reversed phase ODS column without end-capping treatment over a pH ranging from 6.4 to 9.2, but failed on the end-capped ODS column. This suggests that the presence of residual silanol groups on the ODS is an important factor for the separation.