Trifluoroacetic Acid and Longer Chain Perfluoro Acids-Sources and Analysis

Abstract

Perfluorinated organic acids are ubiquitous in the environment at relatively low concentrations and appear to be highly persistent. Analytical techniques have relied primarily on GC-based methods, and for the lowest member TFA involve derivatization. The longer chain perfluoro acids have only recently been routinely analyzed at environmental concentrations using electrospray-MS/MS systems. Their analysis at low concentrations in environmental matrices requires extensive concentration. For the longer chain acids, this generally relies on liquid-liquid or SPE based methods and, for TFA anion-exchange or evaporation of water. Industrial and consumer applications are the primary source of emissions of the higher perfluoro acids while TFA results primarily from both the atmospheric degradation of CFC replacements and from the degradation of fluoropolymers in high temperature applications. Except for the question of a natural source, the current knowledge of the environmental chemistry of TFA is relatively mature, whereas that for the higher perfluoro acids is only beginning to emerge.