[Distribution Characteristics and Source Apportionment of Perfluoroalkyl Substances in Surface Soils of the Northeast...

Surface soil samples collected at 18 sites from the northeast Tibetan Plateau were used to analyze perfluoroalkyl substances (PFASs) via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to study the concentration levels and sources of PFASs. The results showed that 11 PFASs were detected in the soil, and the ω(Σ₁₁PFASs) ranged from 0.043-1.573 ng·g^-1 with an average concentration of 0.398 ng·g^-1. PFBA displayed the highest concentration level with a mean content of 0.164 ng·g^-1, whereas PFHxA was at the lowest level (0.005 ng·g^-1). The concentrations of the other PFASs were similar to each other (0.011-0.057 ng·g^-1). Generally, PFASs contents in the west and north were higher than that in the southeast, and the alpine condensation effect existed for PFBA. The principal component analysis showed that PFASs in surface soils in the northeast Tibetan Plateau region mainly originated from the atmospheric transport of PFASs and their precursors. Few areas were affected by direct emissions of point source pollution, and the main sources were the industrial production of metals/minerals and other human activities.