Determination of semi-volatile fluorinated compounds in environmental samples by solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS)

Abstract

Fluorinated organic compounds (FOCs) constitute a wide group of organic compounds, which are partially or totally saturated by fluorine atoms. Over the last years, perfluoroalkyl and polyfluoroalkyl substances (PFASs), which constitute a huge group of hazardous organic contaminants, have drawn great attention due to their persistence, potential toxicity and ubiquitous presence in the environment. Thus, PFASs have been substituted by semi-volatile PFASs in many different applications such as fire-fighting foams, paintings, coating and packaging materials. Although these compounds do not present a strong toxicity, their degradation into persistent perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) makes necessary to control their presence in the environment as well as in wildlife and humans. In the present work, a fast and simple analytical method for the simultaneous determination of several families of semi-volatile PFASs, including fluorotelomer alcohols (FTOHs), perfluorooctanesulfonamide (FOSA), perfluorooctanesulfonamide ethanol (FOSE) and fluorotelomer olefins (FTOs), in water samples has been optimised and validated. The proposed method consists on headspace solid-phase microextraction (HS-SPME) technique for the target compounds extraction and determination by gas chromatography-mass spectrometry (GC-MS), which provided good trueness, sensitivity and precision achieving very low method limits of detection ranging from 0.10 ng L-1 to 1.93 μg L-1. The validity of the method has been demonstrated for the analysis of water samples. The established method was applied to the analysis of semi-volatile PFASs precursors in water samples collected from different sources such as the Llobregat River, Barcelona tap water and seawater for alimentary purposes