Development of the radiosynthesis of high-specific-activity 123I-NKJ64

The radiosynthesis of 123I-NKJ64 was achieved with good isolated radiochemical yield of 68% and a high specific activity of 1.8 Ci/μmol. TFA was found to be the most suitable deprotecting agent, since 2 M HCl generated a by-product that could not be fully separated from 123I-NKJ64 using the HPLC methodology investigated. This study highlights the importance of HPLC purification and accurate measurement of specific activity while developing new radiosynthesis methodologies.