Analisi multiresiduale LC-MS mediante arricchimento in linea del campione (on-line SPE/UHPLC-ESI-MS/MS) per la determinazione di acidi perfluoroalchilcarbossilati e perfluoroalchilsolfonati nelle acque dolci naturali

An UHPLC-ESI-MS/MS multi-residue method based on an on-line SPE procedure for the simultaneous determination of 9 perfluoroalkyl carboxylates (from 4 to 12 carbon atoms) and 3 perfluoroalkyl sulphonates (4, 6 and 8 carbon atoms) is described. The results of the in house validation, for 5 mL injection, showed good linearity ranges spanning two orders of magnitude between LOQ and 100 ng/L for PFUnDA and PFDoDA and LOQ and 200 ng/L for the other compounds. The percentage of recoveries, between 76 and 134%, calculated in different matrices (tap water and rivers impacted by different pollutions) were generally satisfactory. LODs and LOQs of this on-line SPE method, which also incorporate recovery losses, ranged from 0,2 to 5.0 ng/L and from 1 to 20 ng/L respectively. The linking of the sample extraction and the chromatographic analysis allows to limit the volume of sample to be collected, to reduce handling steps (centrifugation and the acidification of the sample before injection) and obtain a high-throughput analytical method to be implemented in of environmental monitoring programs.