Determinazione di acidi perfluoroalchilici in biota e sedimento mediante LC-MS/MS accoppiata alla purificazione on-line degli estratti tramite Turbulent Flow Chromatography

A new method was developed for the analysis of 8 perfluoroalkyl carboxylic acids (PFCA) from 5 to 12 carbon atoms and 3 perfluoroalkyl sulfonic acids (PFSA) of 4, 6 and 8 carbon atoms in environmental samples (biota and sediment). The method includes sonicated-assisted extraction with acetonitrile and the purification online of the extract by Turbulent Flow Chromatography (TFC) coupled to the analysis with Ultra High Performance Liquid Chromatography - Mass Spectrometry (UHPLC-MS/MS). The quantitation is performed by isotopic dilution using stable isotope labelled standards. In biological samples the phospholipids are further removed using Ultra HybridSPE®Phospholipid cartridges. The linearity, in a range of two orders of magnitude (between 0.5 and 50 g/L to PFUnDA and PFDoDA and between 1 and 100 mg/L for the other compounds), was good and the recoveries of the compounds in mussel samples are comprised between 98 and 133% for PFCA and between 40 and 60% for the PFSA. MLD and MLQ vary between 0.03 and 0.3 ng/g ww and from 0.1 to 0.9 ng/g ww, respectively. The repeatability (intra-day precision) shows RSD from 3 to 13% while the reproducibility (inter-day precision) from 4 to 27%. This method, which provides a high automation and limits sample manipulation, allows a high analytical productivity in environmental monitoring programs.