Assessment on data processing methods for nontarget identification of per- and polyfluoroalkyl substances using liquid chromatography-high-resolution mass spectrometry

∶2 FTSA）， five chlorinated polyfluoroethersulfonic acids （Cl-PFESAs）， two hydrogen-substituted polyfluoroethersulfonic acids （H-PFESAs）， and four polyfluoroethersulfonic acids （PFESAs）. Their presence was largely attributed to the use of chrome mist suppressants in the electroplating process. Combining DDA and DIA data for FluoroMatch input captured more information on unknown PFAS， possibly because the inclusion of multiple samples improves peak extraction. Based on the performance of PFAS identification in spiked and real samples， we developed a processing method that couples DDA and DIA data. This method can generate a composite list of identified PFAS while keeping data files independent， increasing the true positive rate and efficiency of identification. This study systematically evaluated nontargeted PFAS data processing methods， clarifying the optimal combination of tools for key steps （acquisition mode， peak picking， and deconvolution）， and validating its application potential in complex environmental matrices.