Analysis via Liquid Chromatography-Tandem Mass Spectrometry

4 Analysis via Liquid Chromatography-Tandem Mass Spectrometry 

Liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) is the analytical technique of choice for measurement of ionic PFCs in environmental samples. Recent reviews on the use of this technique for the analysis of PFCs have been published by de Voogt and Saez [111] and Villigrasa, Lopez de Alda and Barcelo [96]. 

Reverse phase liquid chromatography has typically been used for the separation of PFCs, employing either Cg or Cig columns [96], although the use of perfluoroalkyl columns has also been reported [115]. Mobile phases are typically mixtures of methanol-water or acetonitrile-water and are often modified with ammonium acetate to improve chromatographic separation and MS sensitivity. Both isocratic and gradient elution methodologies have been employed [96]. LC-MS/MS methods [116, 117] have also been developed for the separation of PFSA and PFCA isomers and generally employ linear perfluorooctyl stationary phases and acidified mobile phases. 

Class Analyte Precursor product transitions monitored Nature of product ion 

In addition to ionic PFCs, LC-MS/MS has also been employed for the analysis of neutral PFCs. PFOS A is commonly analysed as it can be deprotonated in solution. The precursor product transition that is typically monitored and used for quantitation is 498 78 (SNO2Q [105]. NMeFOSE, NEtFOSE and the FTOHs have also been analysed via LC-MS/MS. These PFCs produce very little molecular ion and are typically monitored as alcohol-acetate adducts [111, 118]. 

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