“…The total yield of the radiotracer consists of free [ 125 I] -iodide and [ 125 I] -ZEN it is calculated from the percentage (%), on TLC at RTs (retention times) 0.0 and 0.9–1.0 respectively. HPLC analysis revealed the following, the purity for [ 125 I]-ZEN reached 99 % [ [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] , [111] , [112] , [113] , [114] , [115] , [116] , [117] , [118] , [119] , [120] ]. The Retention times values for both the free iodide and the labeled molecule [ 125 I]-ZEN existed at 4.5 and 15.8 min, respectively, with regard to the retention time for ZEN that was 14.7 min ( Fig.…”