Separation and fluorine nuclear magnetic resonance spectroscopic (19F NMR) analysis of individual branched isomers present in technical perfluorooctanesulfonic acid (PFOS)

The production of perfluoroalkylsulfonate (PFOS) derivatives from linear alkyl precursors using electrochemical fluorination is not a clean process but, instead, gives complex mixtures. This study reports the isolation and 19F NMR characterization of eleven perfluorooctanesulfonate isomers from a commercial mixture. This allowed the quantification of the individual CF3 branched isomers that predominate in technical PFOS.