A rapid method for the detection and quantification of legacy and emerging per- and polyfluoroalkyl substances (PFAS) in bird feathers using UPLC-MS/MS

The bioaccumulation and toxicity of per- and polyfluoroalkyl substances (PFAS) have raised scientific and public concern in recent decades, leading to regulatory measures for some PFAS (e.g. perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)). In addition, the discovery of new PFAS alternatives in the environment has led to growing concern about the presence of numerous other PFAS that are used unrestricted. Feathers have been successfully applied as non-destructive indicators for various contaminants, mostly metals and persistent organic pollutants (POPs), whereas their suitability as an indicator for PFAS is still discussed. Previous studies on PFAS in feathers have focused primarily on perfluoroalkyl sulfonic acids (PFSAs) and perfluoroalkyl carboxylic acids (PFCAs); analytical methods for other groups of PFAS or PFAS alternatives in feathers are still lacking. Hence, this study aimed to develop a rapid, sensitive and reliable analytical method for determining a broad range of PFAS (N = 32) in feathers, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). An extraction duration of 24 h was found to be sufficient to extract the majority of PFAS from the feathers. The extraction recovery of the internal standards ranged on average from 68% (PFBA) to 97% (PFOS). The spike recovery was within an acceptable range of at least 70% for most of the target analytes and the precision was often > 80%. A further extract clean-up using weak anion exchange (WAX) solid phase extraction (SPE), was proven unnecessary, as it resulted in a similar or lower spike recovery, and, as a consequence, a lower precision and higher quantification limit. The analytical method allows detection of low PFAS concentrations in a low quantity of matrix (i.e. small feathers). The developed LC-MS/MS method was validated and shown to be a fast, sensitive and reliable method for determining a broad range of legacy and emerging PFAS in feathers.