RESUMO
Perfluorooctane sulfonate (PFOS) is a class of specialty chemicals used in a variety of applications, and has been found to be globally distributed in many living organisms including humans. Several analytical methods have been developed for determination of PFOS in environmental samples and biological matrices. However, these methods employ liquid chromatography/tandem mass spectrometry (LC/MS/MS), an instrumentation which has limited accessibility because it is expensive to use and maintain. In the present study we present the development of a robust analytical method using liquid chromatography/mass spectrometry (LC/MS) in combination with solid phase extraction. The high yield and concentration of the present method enabled us to quantify PFOS as low as 0.1 ng/L. This method was applied to the determination of PFOS in 142 surface water samples collected from various geographic locations around Japan. The geometric mean (geometric standard deviation) (ng/L) for river samples (n = 126) was 2.37 (4.13), with a median of 1.68 and a range of 0.3-157 ng/L, and for coastal sea water samples (n = 16) was 1.52 (4.14), with a median of 1.21 and a range of 0.2-25.2 ng/L. However, the concentrations in most of the samples were much lower than the values reported in the US, except for those from the Jinzu (135.0 ng/L) and Tama (157 ng/L) Rivers. Because surface waters in the Ara (13.0-38.5 ng/L), Tama (0.7-157.0 ng/L), and Yodo (0.9-27.3 ng/L) Rivers, sources of drinking water for more than eight million people, were moderately contaminated with PFOS, more work is needed to assess exposure to PFOS.
