Analysis of filtration loss and influencing factors of syringe filters for per- and polyfluoroalkyl substances

The study conducted a quantitative analysis of the mass loss of 32 per- and polyfluoroalkyl substances (PFASs) in three different solvent systems (100% methanol, 50% methanol/water, and 30% methanol/water) using filters made from four different materials (hydrophobic polytetrafluoroethylene (PTFE), hydrophilic PTFE, nylon (NYL), and polyethersulfone (PES)) with two varying pore sizes (0.22 μm and 0.45 μm). The results revealed that both the filter material and pore size had significant impacts on PFASs mass loss in the 100% methanol system, with NYL filters demonstrating the highest average mass loss at 43.8%, while PES filters exhibited the lowest at 6.7%. In general, filters with a pore size of 0.22 μm resulted in greater mass loss compared to those with a pore size of 0.45 μm. Additionally, there was significant variation in PFASs mass loss across different solvent systems, with the least amount of loss occurring in the 100% methanol system, whereas long-chain PFASs experienced up to a maximum of 100% mass loss in the 30% methanol/water system. These findings provide guidance for selecting appropriate filters prior to chromatographic analysis and are essential for accurately quantifying trace emerging contaminants.