Development and optimization of Liquid Chromatography (LC)-Trapped Ion Mobility Spectrometry (TIMS)-Mass Spectrometry (MS) method for Per- and Polyfluoroalkyl Substances (PFAS) quantification and detection.

Abstract

Per- and polyfluoroalkyl substances (PFAS) are considered as persistent organic pollutants widely used across industrial and consumer applications, leading to ubiquitous environmental contamination. Their regulation in Europe encompasses only legacy PFAS. However, the number of PFAS species increases constantly with the apparition of emerging PFAS, which are not regulated, but concerns are growing over their persistence, their potential toxicity, and their mobility in various environmental media. Analytical monitoring remains particularly challenging due to their structural diversity and broad range of chain lengths. These constraints highlight the need for highly sensitive analytical tools capable of reliably identifying and quantifying PFAS in complex environmental matrices. Liquid chromatography coupled with mass spectrometry (LC-MS) is the current reference technique for PFAS analysis, yet it faces limitations in resolving isomers and distinguishing coeluting isobars. Ion mobility spectrometry (IMS), positioned between LC and MS, offers an additional dimension of separation that can improve isomer resolution and enhance overall analytical confidence. The objective of this work was to develop and optimize an LC-IMS-MS method for both the quantification and detection of PFAS. First, a targeted method was established for the quantification of PFAS ranging from ultra-short-chain to long-chain PFAS of PFCA and PFSA in water, in accordance with European regulatory requirements. Second, an analytical strategy was designed and evaluated to support future non-targeted analysis of PFAS, laying the groundwork for broader screening approaches capable of capturing both legacy and emerging PFAS.