Quantification of per- and polyfluoroalkyl substances with a modified total organic carbon analyzer and ion chromatography

Abstract

Quantification of per- and polyfluoroalkyl substances (PFAS) via mass spectrometry is highly sensitive but targets a limited number of compounds and the instrumentation is not available in many laboratories. We developed a methodology to determine total organofluorine by modifying a total organic carbon analyzer, which is common in laboratories across disciplines. Evolved hydrogen fluoride was captured in an impinger and analyzed by ion chromatography. Recovery of fluorine from 20 PFAS was dependent on terminal functional group and alkyl chain length. The method detection limit based on perfluorooctanoic acid (PFOA) spiked samples was 36 μg-F/L (52 μg PFOA/L). Fluorine recoveries of spiked PFAS in river water and wastewater were similar to those spiked in deionized water. The recovery of inorganic fluorine present in sodium fluoride was 91%. Therefore, researchers should be cautious when applying methods that pre-combust samples to differentiate organo- and inorganic fluorine, because the combustion process may cause inadvertent losses of inorganic fluorine, resulting in an overestimation of organofluorine. Article Impact Statement: Results enable the quantification of per- and polyfluoroalkyl substances using equipment present in a greater number of laboratories than mass spectrometry-based methods.