Development of a procedure for the determination of perfluorocarboxylic acids in sediments by pressurised fluid extraction, headspace solid-phase microextraction followed by gas chromatographic–mass spectrometric determination

A procedure for the determination of perfluorocarboxylic acids (i.e. PFC7–10A) in sediment by pressurized fluid extraction (PFE), derivatization, headspace solid-phase microextraction and GC–MS determination in the negative ion chemical ionisation mode was developed. The PFE extraction variables such as solvent composition, number and time per extraction cycle, and extraction temperature were optimised. In the optimum extraction conditions, recoveries exceeding 95% with a limit of detection and RSDs of 0.5–0.8 ng g−1 and 15.5–16.8%, respectively, were obtained. The developed analytical procedure was applied to harbour sediments where PFC8A and PFC10A were detected for the first time at low ppb concentrations (i.e. 8–11 ng g−1).