Separation of perfluoroalkylsulfinic acids and perfluoroalkylsulfonic acids by ion-exclusion chromatography

Ion-exclusion chromatography has been successfully applied to the separatio n of a number of perfluoroalkylsulfinic acids and perfluoroalkylsulfonic ac ids. The separation of various perfluoroalkylsulfinic and perfluoroalkylsul fonic acids, with different alkyl groups, was investigated on a polymethacr ylate-based, weakly acidic, cation-exchange resin (TSK gel OApak-A) in the H+-form and using conductimetric detection. When water was used as the elue nt, these perfluoroalkylsulfinic and perfluoroalkylsulfonic acids could not be resolved. When an aqueous solution of benzoic acid and o-phthalic acid was used, the separation of each of these acids occurred. In order to impro ve their separation, the effect of the addition of methanol and 2,2,2-trifl uoroethanol, as organic modifiers, was also investigated. (C) 2001 Elsevier Science B.V. All rights reserved.