Analysis of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in air emission samples by GC-HRMS: method development, validation and a real-case application

• GC-HRMS method for PBDD/Fs analysis. • Chlorinated-solvent-free extraction and clean-up workflows. • Enhanced sensitivity for highly brominated congeners. • Sub-pg Nm -3 quantification limits. • Eleven-month industrial stack emission monitoring application. Polybrominated dibenzo- p -dioxins and dibenzofurans (PBDD/Fs) are emerging dioxin-like pollutants formed during bromine-containing thermal processes, yet not harmonized analytical methods currently exist for their determination in atmospheric emissions. Most applications adapt PCDD/F protocols despite the distinct physicochemical behaviour of brominated analogues and their associated analytical challenges. Here, an improved GC-HRMS method is presented for the determination of the thirteen commercially available 2,3,7,8-PBDD/F congeners in air emissions, providing an alternative sample preparation workflow avoiding dichloromethane during clean-up and fractionation. Key instrumental parameters –pulsed splitless injection, pulse conditions, inlet temperature, carrier gas flow and electron ionization energy– were optimized to enhance sensitivity across tetra- to octabrominated congeners. Sample preparation consisted of 20 h Soxhlet extraction with toluene, followed by a simplified multilayer silica column (without AgNO 3 ) and an activated carbon fractionation, enabling a selective PBDE-PBDD/F separation through planarity-based retention. Method validation, following criteria adapted from EN 1948 and EPA 1613, demonstrated satisfactory analytical performance, including linearity over at least two orders of magnitude (relative response factor RSD ≤ 9 %), repeatability of 0.8-6.1 % in real emission matrices, accuracy ranging from -7.6 % to +17.4 %, and method quantification limits of 0.014-0.429 pg Nm -3 . Application to an eleven-month industrial monitoring campaign confirmed method robustness under routine conditions and enabled congener-resolved PBDD/F profiling and provisional I-TEQ and WHO 22 -TEQ assessment. Overall, the present study reports a validated and integrated DCM-free analytical workflow for PBDD/F, providing a practical expansion of available strategies for future monitoring and standardisation efforts.