SF Dong1* , ML Lu1 , R Wahlen2

1 Agilent Technologies Co. Ltd (China), Beijing 100102, China

2 Agilent Technologies Ltd, 5500 Lakeside, Stockport, SK8 3GR, UK

*shuo-fei.dong@agilent.com

On a global scale, PFAS are ubiquitous in a variety of environmental media. Their persistence and potential human health effects have raised interest in their migration and fate in the environment. The investigation of PFAS in environmental media is comprehensive, especially for its transformation in the atmosphere, surface water and groundwater. However, as soil is an important reservoir and long-term source of PFAS and other pollutants, a rapid quantitative analysis method of the total amount of PFAS in soil is needed to help study its role in the environment more conveniently [1]. Existing PFAS quantification methods can quantify more than 40 PFAS compounds, but many of the PFAS compounds that are used in industrial applications are not included. Therefore, monitoring the total amount of high concentrations of fluorinated organic compounds in the sample, and then focus on qualitative and quantitative analysis of PFAS in the high content sample is a practicable workflow. The common method for determining total fluorine in PFAS is to convert fluorine in organic matter into fluoride ions, and then use fluoride selective electrode method or ion chromatography to detect it. After the initial establishment of the method for the quantitative detection of fluoride ions by ICP-MS/MS in 2015[2], it has been further developed and applied to the detection of total fluoride in water and tea in recent years.

In this study, the method was further developed for the quantitative detection of total fluorine of PFAS in soil samples. Preliminary results showed that the detection limit of total fluorine was less than 10 ng/ml. The soil samples were extracted and purified by SPE, and the final eluent was detected by ICP-MS/MS for total fluorine concentrations, and 23 PFAS compounds were quantified by LC-MS/MS. The results of the analysis showed that the total fluorine content was approximately three times of the 23 PFAS compounds (calculated as fluorine), indicating that many unknown organic fluorides in the analysed soil samples, and further investigation of whether these unknown organic fluorides pose an environmental health risk is needed.

References

[1] ML Brusseau, RH Anderson, B Guo. PFAS concentrations in soils: Background levels versus contaminated sites. Sci Total Environ. 2020, 740:140017

[2] N.L.A. Jamari, et al., Novel non-target analysis of fluorine compounds using ICPMS/MS and HPLC-ICPMS/MS, J. Anal. At. Spectrom. 2017, 32 (5), 942-950.