Metrohm presents a direct-injection method for perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) determination in drinking water.
The current method for the determination of anionic perfluorinated surfactants is LC-MS/MS.
The analytical methods for the determination of PFOS and PFOA in water samples generally employ a C18-SPE column, either with or without ion pairing or acidification, followed by LC-MS/MS.
This method, however, suffers from relatively high running and investment costs.
The Metrohm method is an alternative that takes into account investment on instrumentation and usability.
The method is based on suppressed ion chromatography with isocratic elution on a reversed-phase column thermostated at 35C using an aqueous mobile phase containing boric acid and acetonitrile.
The detection technique used is conductivity.
While PFOA and PFOS determination in low salt-containing water samples can be performed using straightforward direct-injection chromatography, samples with higher alkaline-earth-metal concentration should pass over a cation exchanger such as Metrohm's sample preparation module (SPM) prior to separation.
