Spatial distribution of perfluorooctane sulfonate (PFOS) in major rivers in southwest Nigeria

Concentrations of perfluorooctane sulfonate (PFOS) were measured for the first time in major rivers within southwest, Nigeria. PFOS was concentrated from water and sediment using solid-phase extraction, identified and quantified with high-performance liquid chromatography coupled with tandem mass spectrometry. Concentrations of PFOS ranged from 1.71 to 16.19 ng L−1 in water, and from 1.64 to 10.29 ng g−1 in sediments across all locations. Comparatively, the concentrations of PFOS observed in this study were within the range ever measured in the environment. Field-based sediment water distribution coefficients (log Kd, L kg−1) ranged from 2.08 to 3.56. While no correlation was observed between Kd and organic carbon contents, there was significant positive correlation between Kd and salinity (r2 = 0.7867), which suggested that activities capable of increasing salinity can enhance PFOS removal from the environment.