Quantification of fluorotelomer-based chemicals in mammalian matrices by monitoring perfluoroalkyl chain fragments with GC/MS

The GC/MS method was developed and tested based on selected ion monitoring of perfluorinated alkyl parent chain fragment ions and demonstrated the simultaneous detection of both volatile and non-volatile fluorotelomer-based chemicals in complex matrices, such as mammalian tissues, as an alternative method of analysis for laboratories without access to LC-MS/MS.

Abstract

Perfluorocarboxylic acids (PFCAs), namely perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA), have been identified as persistent, bioaccumulative and potentially toxic compounds. The structural analog, 8-2 fluorotelomer alcohol (8-2 fTOH) is considered the probable precursor of these stable metabolites. Because simultaneous quantification is needed for volatile and non-volatile perfluorinated chemicals (PFCs) in complex matrices, a GC/MS method was developed and tested based on selected ion monitoring of perfluorinated alkyl parent chain fragment ions. Although the method requires a derivatization step, combined GC/MS analysis of PFCA-me's and FTOHs increases analytical efficiency and decreases sample analysis time. The method instrument detection limits are between 7.1 and 24.5 ng/mL extract (MTBE), and the method quantification limits are below 50 ng/mL serum or ng/g liver for all PFCs investigated. Recoveries from mouse serum and liver homogenates, which were spiked with FTOHs and PFCAs at levels of 25 and 200 ng/mL or ng/g, ranged from 81 to 101%. Finally, the utility of the method was demonstrated by dosing male CD-1 mice with 30 mg/kg-BW of 8-2 fTOH and quantifying PFCs 6h post-treatment. The advantages of this method are (1) the simultaneous detection of both volatile and non-volatile fluorotelomer-based chemicals in complex matrices, such as mammalian tissues, (2) as a confirmatory method to LC-MS/MS, and (3) as an alternative method of analysis for laboratories without access to LC-MS/MS.