Wet deposition and dry deposition of legacy per- and polyfluoroalkyl substances (PFAS) and perfluoroalkyl ether carboxylic acids (PFECAs) were assessed on the southeastern coast of the United States, specifically, in Wilmington, NC, which is located 110 km from a fluorochemical manufacturer. Analytes were quantified by liquid chromatography coupled to electrospray ionization with triple-quadrupole mass spectrometry. Total concentrations of six PFAS compounds ranged from below the method quantification limit to 110 ng L^–1 by wet deposition, and total fluxes of 0.3–29 ng m^–2 day^–1 by dry deposition were found. The estimated annual flux of all six PFAS was 30 μg m^–2 by wet deposition and 1.4 μg m^–2 by dry deposition, indicating that PFAS are more effectively removed from the atmosphere by wet deposition. There was a significant rainout/washout effect observed in our data, but there was no impact of the origin of the air mass on concentration or flux, suggesting that the incorporation of PFAS into rainwater is a relatively local phenomenon. This study shows the first direct evidence of PFECAs in wet and dry deposition. The data suggest that the particle-bound and gas-phase PFAS that may have undergone long-range transport can be incorporated into raindrops and removed rapidly.

中文翻译：

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美国北卡罗来纳州威尔明顿的传统全氟烷基物质的大气沉积和年通量以及全氟烷基醚羧酸的置换

在美国东南沿海，特别是北卡罗来纳州的威尔明顿市，对传统的全氟烷基物质和多氟烷基物质（PFAS）和全氟烷基醚羧酸（PFECAs）进行了湿式沉积和干式沉积评估，该地区距氟化物制造商110公里。通过液相色谱与三重四极杆质谱联用电喷雾电离对分析物进行定量。六种PFAS化合物的总浓度通过湿法沉积在方法定量限值以下至110 ng L ^–1之间，通过干法沉积法发现的总通量为0.3–29 ng m ^–2天^–1。通过湿法沉积，全部六个PFAS的估计年通量分别为30μgm ^–2和1.4μgm ^–2通过干法沉积，表明通过湿法沉积更有效地从大气中去除了PFAS。在我们的数据中观察到了显着的降雨/冲刷效果，但是空气质量的起源对浓度或通量没有影响，这表明将PFAS掺入雨水中是一个相对局部的现象。这项研究显示了干湿沉积中PFECA的第一个直接证据。数据表明，可能经历了远距离迁移的与颗粒结合的气相PFAS可以并入雨滴并迅速去除。