Seasonal variation of trifluoroacetic acid (TFA) in Antarctic ice cores analysed by direct injection non-suppressed...

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Analytical Chemistry

Background:

• Trifluoroacetic acid (TFA) is a persistent, mobile, and stable ultra-short chain perfluoroalkyl acid (PFAA).
• TFA is an end product of atmospheric degradation of hydrofluorocarbons (HFCs) and unsaturated HFCs (u-HFCs).
• Understanding TFA's long-range transport and deposition in remote areas like Antarctica is crucial.

Purpose of the Study:

• To report the first detection of TFA in Antarctic ice cores.
• To establish a high-resolution record of TFA deposition from 2011-2021.
• To investigate the relationship between TFA deposition and atmospheric phenomena.

Main Methods:

• Development of a novel non-suppressed ion chromatography-tandem mass spectrometry (nsIC-MS/MS) method for TFA analysis.
• Analysis of 260 samples from a 12.9 m Antarctic ice core using direct injection.
• Utilized a HALO Penta-HILIC column with optimized chromatographic conditions for rapid TFA separation.

Main Results:

• First record of TFA in Antarctic ice cores, spanning 2011-2021.
• Average TFA concentrations increased by 5.8% annually.
• Observed TFA peaks in September-November correlated with polar vortex weakening, indicating release of TFA and its precursors.

Conclusions:

• Antarctic ice cores provide a valuable archive for tracking TFA deposition and atmospheric transport.
• The increasing trend of TFA highlights the global reach of HFC degradation products.
• Polar vortex dynamics influence the seasonal release of TFA in polar regions.