A new liquid chromatography–fluorescence method for determination of perfluorooctanesulphonyl fluoride upon derivatisation with 1-naphthol

Abstract

Perfluorooctanesulphonyl fluoride (PFOSF), as a main precursor of perfluorooctanesulphonate (PFOS) that is ubiquitous in the environment, has been released to the environment with substantial quantity. Determination of PFOSF presents significant analytical challenges for using liquid chromatography with UV (LC–UV) and fluorescence detection (LC–FLD) due to the lack of chromophore in the molecular structure. In this study, a new method was developed by derivatising PFOSF with 1-naphthol to form 1-naphthylperfluorooctanesulphonate (NPFOS), which allowed rapid qualitative and quantitative analysis using LC–UV and LC–FLD. The derivatising product was confirmed from the analyses by proton nuclear magnetic resonance and quadrupole–time of flight mass spectrometry. The LC–FLD method demonstrated good linearity in the NPFOS concentration range from 20 pg µL⁻¹ to 20 ng µL⁻¹ with a correlation coefficient better than 0.999, with the instrument detection limit of 1.5 pg µL⁻¹.

Keywords:

• perfluorooctanesulphonyl fluoride
• POPs
• derivatisation
• LC–FLD

Acknowledgement

The authors thank Ms Silvia T. Mo, Ms Ruth W.Y. Chu, Mr David T.W. Chik and Mr John S.L. Ng from the Department of Chemistry, Hong Kong Baptist University, for the technical support in the research.

Supplemental data

Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/03067319.2014.954563/.