High-performance liquid chromatography with conductimetric detection of perfluorocarboxylic acids and perfluorosulfonates

A rapid and simple method for separating and determining various environmentally harmful perfluorocarboxylic acids and perfluorosulfonates was successfully developed using high- performance liquid chromatography with conductimetric detection, for product and waste management of these compounds at manufacturing and processing sites. Compounds having C3–C8 perfluoroalkyl groups were separated using a Tosoh TSKgel Super-ODS column and a mobile phase consisting of a mixture of methanol and aqueous NaH2PO4 at several mixing ratios. The best detection limits for the compounds ranged from 0.12 to 0.66 mg l−1 (ppm), and linear calibration graphs were obtained up to 87–109 mg l−1. The combination of this method with concentration of the sample by solid-phase extraction with cartridges based on styrene-divinylbenzene-copolymer enabled the determination of ≈50 μg l−1 (ppb) for compounds with C4–C8 perfluoroalkyl groups. This method was successfully used to monitor the artificial decomposition of the perfluorocarboxylic acid n-C4F9COOH induced by a photocatalyst.