SYSTEMATIC ASSESSMENT OF ANALYTICAL TECHNIQUES FOR THE TRACE-LEVEL DETECTION OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) IN COMPLEX ENVIRONMENTAL AND BIOLOGICAL MATRICES

Per- and polyfluoroalkyl substances (PFAS) are globally recognised as persistent organic pollutants of substantial environmental and public health concern as a result of their toxicity, bioaccumulation, and chemical stability. The detection of PFAS at trace and ultra-trace levels in complex matrices remains an analytical challenge due to the presence of numerous unknown analogues and the diverse physicochemical properties of PFAS. This systematic review critically evaluates 55 peer-reviewed studies published between 2010 and 2025 that focus on analytical techniques for quantifying and identifying PFAS in environmental and biological samples. The assessment follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and compares the performance of major analytical platforms, including liquid chromatography tandem mass spectrometry (LC–MS/MS), ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC–HRMS), gas chromatography mass spectrometry (GC–MS), extractable/adsorbable organofluorine (EOF/AOF), surface-enhanced Raman spectroscopy (SERS), and electrochemical or hybrid sensor-based approaches. LC–MS/MS and UHPLC–HRMS remain the gold standards for quantitative and non-target PFAS analysis, respectively, while emerging spectroscopic and electrochemical methods offer rapid, portable, and cost-effective alternatives. Molecularly imprinted polymers, deep eutectic solvents, and bubble-assisted extraction are among the sample preparation advancements that have further enhanced environmental sustainability and sensitivity. The review highlights the need for standardized QA/QC protocols, certified reference materials, and inter-laboratory harmonization. Integration of artificial intelligence, green chemistry, and multi-platform detection systems represents the future direction for comprehensive PFAS monitoring and exposure assessment. Keywords: Per- and Polyfluoroalkyl Substances, Mass Spectroscopy, Non-target analysis, Surface-Enhanced Raman Spectroscopy, Environmental monitoring.