Determination of Gaseous and Particulate Trifluoroacetic Acid in Atmosphere Environmental Samples by Gas Chromatography-Mass Spectrometry
Trifluoroacetic acid (TFA) concentration was measured in air samples by a sampling device composed of annular denuders coupled with a quartz filter,which was efficient for 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 chromatographymass spectrometry after derivation with 2,4-difluoroaniline.Calibration curves were linear with a correlation coefficient of 0.9991.Detection limit of TFA was 66 ng/L,which was 31 pg/m3 when sampling volume was 48 m3.Recoveries of the TFA sampling device ranged between 98% and 105% with relative standard deviation (RSD) ≤ 3%.The developed method was applied for the determination of TFA in atmosphere samples collected in Peking University in Beijing in 2012.Total TFA concentrations ranged between 501 and 7447 pg/m3.Concentrations of gaseous TFA were significantly higher than those of particulate,and the gasparticle partition coefficient of TFA decreased as air temperature rose.