Ascertaining the Suitability of Aryl Sulfonyl Fluorides for [<sup>18</sup>F]Radiochemistry Applications: A Systematic Investigation using Microfluidics MatesicLidia WyattNaomi A. FraserBenjamin H. RobertsMaxine P. PhamTien Q. GreguricIvan 2013 Optimization of [<sup>18</sup>F]­radiolabeling conditions and subsequent stability analysis in mobile phase, PBS buffer, and rat serum of 12 aryl sulfonyl chloride precursors with various substituents (electron-withdrawing groups, electron-donating groups, increased steric bulk, heterocyclic) were performed using an Advion NanoTek Microfluidic Synthesis System. A comparison of radiochemical yields and reaction times for a microfluidics device versus a conventional reaction vessel is reported. [<sup>18</sup>F]­Radiolabeling of sulfonyl chlorides in the presence of competing nucleophiles, H-bond donors, and water was also assessed and demonstrated the versatility and potential utility of [<sup>18</sup>F]­sulfonyl fluorides as synthons for indirect radiolabeling.