L monitoraggio di sostanze perfluoroalchiliche (PFAS) in Toscana: Metodologia e Risultati

Abstract

Considering that the monitoring activity is mandatory at European level, in 2016 ARPA Toscana developed a method of analysis of these compounds based on on-line solid phase extraction (SPE) and on detection and quantification through high performancechromatography interfaced with a high resolution mass selection spectrometer system (HPLC-HRMS) based on Orbitrap technology. The developed analytical method allows the determinationof perfluorosulfonic acids at the level of 0.5 ng / L (0.0005 I¼g / L) and of perfluorocarboxylic acids at the level of 2 ng / L (0.002 I¼g / L) ,in surface waters and groundwater. This method has been validated through a collaboration with IRSA-CNR (duplicate analysis of samples collected in Tuscany and analyzed by IRSA during 2013) and through participation in interlaboratory circuits (AGLAE). During last year 13 samples of water from Arno River and additional 29 samples from further 11 surface water bodies were analyzed for PFAS. Regarding groundwater, PFAS determinations were carried out in 40 wells, in the following aquifers: Sieve, Pitigliano volcanites, coastal aquifer between Cecina and San Vincenzo, coastal between Fine and Cecina, the Cornia plain, Cerbaie and Bientina deep water, Valdarno lower and coastal plain of Pisa, Val di Nievole Fucecchio area.The evaluation of the obtained analytical results highlights 276 determinations with a value higher than the analytical quantification limit (LOQ), with values also significantly close to the SQA-MA for perfluorooctanoic acid (PFOA) and perfluorbutanulphonic acid (PFBS); the limit for perfluorooctansulphonic acid (PFOS) is exceeded, on 12 stations of the 14 considered.Related to a geographic analysis of the results, it is possible to identify a localization of the most critical situations in the Arno river (middle valley section) and of some of its tributaries (Bisenzio, Elsa Usciana) some situations of less concern can be found in some water bodies of the coast. Some the underground aquifer most affected from presence of PFAS are those in Pistoia district. During 201735 PFOS determinations were carried out on samples of freshwater fish fauna (Barbus plebejus, Salmo truta ecc.) and sea fish fauna (Leuciscus cephalus, Liza aurada, Liza ramada etc.) in compliance with Legislative Decree. 172 of 13/10/2015 and the Marine Strategy project (European Directive 2008/56 / EC and Legislative Decree 190/2010), The ARPAT analytical method for biota implied a modified Quechers extraction, the purification of extracts by extraction in solid phase (SPE) on weak anionic exchange columns (WAX) and the detection and quantification by high performance chromatography interfaced with a spectrometric system with selection of High resolution mass (HPLC-HRMS) based on Orbitrap technology: this allows confirmation and determination of the analyte in question (PFOS) with a LOQ of 0.5 I¼g / kg. The concentantion of PFOS found in all samples was higher than LOQ but less than biota EQS (9.1 I¼g / kg) stated in Dlgs. 172 of 13/10/2015 . Situations close to the EQS were found on specimens of Liza ramada captured near the estuarine of the Arno and with a low concentration on the Livorno coast.On these samples, using retrospective analysis provided by the Orbitrap system, it was possible to identify the typical ion traces of perfluorocansulfonamide (PFOSA), a substance used in various types of water-repellent formulations and perfluorochansulphonate precursors.Â