Derivatization method for sensitive determination of fluorotelomer alcohols in sediment by liquid chromatography–electrospray tandem mass spectrometry

• Develop a dansylation method to analyze FTOHs by UPLC–MS/MS.
• This method was 7.5–241 folds more sensitive than previous method.
• We firstly reported the successful detection of FTOHs in sediment.

Fluorotelomer alcohols (FTOHs) are the main precursors of environmentally ubiquitous perfluorinated acids, and determination of FTOHs at low concentrations presents significant challenges. In this study, a new liquid chromatography–electrospray mass spectrometry (LC–ESI-MS) method in conjunction with low-energy collision dissociation tandem mass spectrometry (CID-MS/MS) was developed by employing an optimized derivatization reaction with dansyl chloride (DNS) in acetonitrile under catalysis of 4-(dimethylamino)-pyridine (DMAP). The instrument detection limits (IDLs) of the newly developed method were 0.014, 0.015, 0.014, 0.0075 and 0.0093 μg/L for 4:2 FTOH, 6:2 FTOH, 8:2 FTOH, 10:1 FTOH and 10:2 FTOH respectively, which were 7.5–241 times lower than those without derivatizaiton and 57–357 times lower than previous GC/MS method. The method was successfully applied to analyze FTOHs in sediments combined with WAX and silica cartridges cleanup. The overall method recoveries were from 67 ± 6.0% to 83 ± 9.4% with matrix effects of <15%. The limits of quantification for all FTOHs were 0.017–0.060 ng/g dry weight (dw). The method was applied to analyze six marine sediment samples from Liaodong Bay, China. All FTOHs except for 10:1 FTOH were detected, and the total concentrations of FTOHs were 0.19–0.52 ng/g dw. The developed method provides a new method to sensitively determine FTOHs in environmental matrices.