Presentation Profile
Development of a Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC–MS) and Liquid GC-MS Method for FTOH and FTAcr
Main Author
Mohammad Jahirul Alam - University of Houston
- Bernhard Rappenglueck - University of Houston
Abstract:
Fluorotelomer alcohols (FTOHs) and fluorotelomer acrylates (FTAcrs) form part of Per- and Polyfluoroalkyl Substances (PFAS), a group of synthetic chemicals that have raised public health concerns due to their persistence and potential toxicity. We have developed and validated a novel method for measuring FTOHs and FTAcrs in ambient air using the same gas chromatography – mass spectrometry (GC-MS) instrument equipped with both a liquid sampler and a thermal desorption unit to minimize instrumental uncertainty. This unified instrumental platform enabled direct comparison of two quantification approaches: (1) liquid extraction for PUF/XAD-2/PUF cartridges and (2) thermal desorption using Tenax and CAMSCO PFAS sorbent tubes. Detection limits ranged from 0.02–0.06 ng/tube for FTOHs and 0.02–0.08 ng/tube for FTAcrs. Stability tests over seven days showed minimal loss ranging from 2.13–3.95% for FTOHs and 2.23–3.34% for FTAcrs. Tube breakthrough was <2% for sample volumes up to 20 L. First measurements in Houston urban air yielded FTOH and FCAcr concentrations up to 4.36 ng/m³ for 8:2 FTOH, and 8.89 ng/m³ for 6:2 FTAcr in the gasphase, and up to 0.36 ng/m³ for 10:2 FTOH and 0.26 ng/m³ for 10:2 FTAcr in particle phase. The results indicate that temperature is an important driver of the atmospheric abundance and phase distribution of FTOH and FTAcr.
