Negative-ion atmospheric pressure ionisation of semi-volatile fluorinated compounds for ultra-high-performance liquid chromatography tandem mass spectrometry analysis
In this work, the feasibility of negative-ion atmospheric pressure chemical ionisation (APCI) and atmospheric pressure photoionisation (APPI) for ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) determination of fluorotelomer alcohols (FTOHs), fluorinated octanesulfonamides (FOSAs) and fluorinated octanesulfonamido-ethanols (FOSEs) was evaluated. The study of the effect of mobile phase composition on the atmospheric pressure ionisation of these compounds indicated that methanol/water mixtures provided the best responses in APCI, while acetonitrile/water with a post-column addition of toluene as dopant was the most appropriated mixture in APPI. Under the optimal working conditions, most of the target compounds produced the ion [M–H]− as base peak, although in-source collision-induced dissociation fragment ions in APCI and APPI and superoxide adduct ions [M+O2]−• in APPI were also present. These ions proved to be more useful as precursor ions for MS/MS determination than the adduct ions generated in electrospray. Although the UHPLC-APCI-MS/MS method allowed the determination of these semi-volatile compounds at low concentration levels, the analysis by UHPLC-APPI-MS/MS provided the lowest limits of detection and it was applied to the analysis of water samples in combination with solid-phase extraction. Quality parameters demonstrated the good performance of the proposed method, providing low method limits of detection (0.3–6 ng L−1), good precision (RSD % < 5%) and an accurate quantification (relative error % < 14%). Among the river water samples analysed by the developed method, 4:2 FTOH and N-EtFOSA were determined at 30 and 780 ng L−1, respectively.
KeywordsFluorotelomer alcohols Fluorinated sulfonamides Fluorinated sulfonamido-ethanols Atmospheric pressure chemical ionisation Atmospheric pressure photoionisation Liquid chromatography tandem mass spectrometry
The authors acknowledge the financial support received from the Spanish Ministry of Economy and Competitiveness under the project CTQ2015-63968-C2-1-P and also from the Generalitat of Catalonia under the project 2018-SGR-310. Juan F. Ayala-Cabrera also thanks the Spanish Ministry of Education, Culture and Sports for the PhD FPU fellowship and the Water Research Institute (IdRA) from University of Barcelona for the PhD research financial assistance.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 2.Hekster FM, Laane RWPM, de Voogt P. Environmental and toxicity effects of perfluoroalkylated substances. Rev Environ Contam Toxicol. 2003;179:99–121.Google Scholar
- 5.Kissa E. Fluorinated surfactants and repellents. 2nd ed. New York: Marcel Dekker; 2001.Google Scholar
- 6.Council Decision (EU) 2015/633 of 20 April 2015 on the submission, on behalf of the European Union, of a proposal for the listing of additional chemicals in Annex A to the Stockholm Convention on Persistent Organic Pollutants. Official Journal of the European Union. 2015;L 104:14–15.Google Scholar
- 7.Decision SC-4/17 of 4–8 May 2009 of Listing of perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride. United Nation Environment Programme. Stockholm Convention on Persistent Organic Pollutants. UNEP/POPS/COP.4/38:66-9.Google Scholar
- 22.Arvaniti OS, Asimakopoulos AG, Dasenaki ME, Ventouri EI, Stasinakis AS, Thomaidis NS. Simultaneous determination of eighteen perfluorinated compounds in dissolved and particulate phases of wastewater, and in sewage sludge by liquid chromatography-tandem mass spectrometry. Anal Methods. 2014;6:1341–9.CrossRefGoogle Scholar
- 25.Bach C, Boiteux V, Hemard J, Colin A, Rosin C, Munoz JF, et al. Simultaneous determination of perfluoroalkyl iodides, perfluoroalkane sulfonamides, fluorotelomer alcohols, fluorotelomer iodides and fluorotelomer acrylates and methacrylates in water and sediments using solid-phase microextraction-gas chromatography/mass spectrometry. J Chromatogr A. 2016;1448:98–106.CrossRefGoogle Scholar