Efficient “total” extraction of perfluorooctanoate from polytetrafluoroethylene fluoropolymer

Abstract

To determine the optimum conditions for the complete extraction of perfluorooctanoate (PFO) from polytetrafluoroethylene fluoropolymers, sample preparation and pressurized solvent extraction (PSE) conditions were investigated. Solvent extraction temperature, solvent residence time, relaxation time between extractions, and the effects of heating before PSE showed that methanol at 150 °C extraction temperature and a 12 min solvent residence time were the most efficient conditions. Preheating the polymer before extraction at 150 °C for 24 h significantly enhanced the quantity of PFO removed. Heating above 150 °C resulted in loss of PFO. PFO was determined by liquid chromatography with tandem mass spectrometry.