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The currently used 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. However, this method suffers from relatively high running and investment costs.
The new Metrohm method is a good alternative regarding both investment on instrumentation and usability. The method is based on suppressed ion chromatography with isocratic elution on a reversed-phase column thermostated at 35 °C using an aqueous mobile phase containing boric acid and acetonitrile. The used detection technique 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, e.g. tap, lake, sludge or river water samples, should pass over a cation exchanger such as Metrohm’s Sample Preparation Module «SPM» prior to separation.
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