Determination of Gaseous and Particulate Trifluoroacetic Acid in Atmosphere Environmental Samples by Gas Chromatography-Mass Spectrometry

Trifluoroacetic acid (TFA) were determined in air samples by a sampling device composed of annular denuders coupled with a quartz filter, which was efficient for the collection and separation of gaseous and particulate TFA. Gaseous TFA was performed by means of annular denuders coated with alkaline solution, while particulate TFA was absorbed by quartz filters. TFA can be determined by gas chromatography-mass spectrometer after derivatizated with 2,4-difluoroaniline. Calibration curves were linear with correlation coefficients of 0.9991. Detection limit of TFA was 66 ng L−1, which was 31 pg m−3 when sampling volume was 48 m3. Recoveries of the TFA sampling device ranged from 98% to 105% with relative standard deviation (RSD) ≤ 3%. The developed method was applied to the determination of TFA in atmosphere samples collected in Peking University in Beijing in 2012. Total TFA concentrations ranged from 501 to 7447 pg m−3. Concentrations of gaseous TFA were significantly higher than those of particulate, and the gas-particle partition coefficient of TFA decreased as air temperature rose.

Correlation between monthly mean gas-particle partition coefficient (Kp) of TFA and temperature in 2012. To obtain Kp, TFA mass concentration in particulate phase was divided by gas concentration.Figure optionsDownload as PowerPoint slide