Determination of perfluorooctane sulfonate, perfluorooctanoate and perfluorooctane sulfonylamide in human plasma by column-switching liquid chromatography-electrospray mass spectrometry coupled with solid-phase extraction.

We report a method for determining fluorinated organic compounds such as perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA) and perfluorooctanesulfonylamide (PFOSA) in human blood samples by column-switching liquid chromatography-electrospray mass spectrometry. The sample preparation prior to solid phase extraction (Waters Oasis HLB extraction column) involved simply mixing plasma sample with internal standard followed by centrifugation and extraction. The compounds were separated by reversed-phase chromatography with a C(8) column, and detected by mass spectrometry using selected ion monitoring in the negative mode. The average recoveries of PFOS, PFOA and PFOSA ranged from 82.2 to 98.7% (R.S.D.: from 2.0 to 5.2%, n = 6). The limits of quantitation of PFOS, PFOA and PFOSA at signal to noise (S/N = 10) were 0.5, 0.5 and 1.0 ng ml(-1). The method enables the precise determination of standards and can be applied to the detection of PFOS, PFOA and PFOSA in human plasma samples for monitoring human exposure.