Fig. 2

Autoradiographic image of mobile-phase optimization for [¹⁸F]FAZA and [¹⁸F]FEPPA. Mobile-phase optimization for a [¹⁸F]FAZA, b [¹⁸F]FEPPA in pig and mouse blood, respectively, at 90 min and 60 min (respectively) post injection, using different fractions of methanol (M), and hexane (H) in ethyl acetate (EA). With each tracer, five different mixtures were used. For [¹⁸F]FAZA only plasma samples were used, while for [¹⁸F]FEPPA each plasma sample was paired with the native tracer in normal saline as the reference (R). The optimal mobile phase would spread the radio-metabolites along the entire lane and move the reference furthest from the spotting line. For [¹⁸F]FEPPA the fourth solution from the left comprised of 8% methanol, 10% hexane and 82% ethyl acetate was optimal, while for [¹⁸F]FAZA, it was the third solution comprised of 7% methanol and 93% ethyl acetate