Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
Rev Environ Contam Toxicol. 2010;208:1-109. doi: 10.1007/978-1-4419-6880-7_1.
Perfluorocarboxylic acids (PFCAs) can be found from the hydrolysis of perfluoroacyl fluorides and chlorides, which can be produced in three separate ways in the atmosphere. Alternatively, PFCAs can be formed directly in the gas phase through reaction of perfluoroacyl peroxy radicals or perfluorinated aldehyde hydrates. All five mechanisms have been elucidated using smog chamber techniques. Yields of the PFCAs from this process vary from less than 10% to greater than 100%, depending on the mechanism. The formation of perfluorosulfonic acids in the atmosphere can also occur, though the mechanism has not been entirely elucidated. A large number of compounds have been confirmed as perfluorinated acid precursors, including CFC-replacement compounds, anesthetics, fluorotelomer compounds, and perfluorosulfonamides. Levels of some of these compounds have been measured in the atmosphere, but concentration for the majority have yet to be detected. It is clear that atmospheric oxidation of volatile precursors contributes to the overall burden of PFAs, though the extent to which this occurs is compound and environment dependent and is difficult to assess accurately.
全氟羧酸（PFCAs）可通过全氟酰基氟化物和全氟酰基氯的水解产生，这两种化合物在大气中可通过三种不同的方式生成。或者，PFCAs 也可以通过全氟酰基过氧自由基或全氟醛水合物的气相反应直接形成。所有这五种机制都已通过烟雾箱技术得到了阐明。该过程产生的 PFCAs 的产率从低于 10%到高于 100%不等，具体取决于机制。尽管尚未完全阐明其机制，但全氟磺酸也可以在大气中形成。大量化合物已被确认为全氟酸的前体，包括 CFC 替代品、麻醉剂、氟代端基化合物和全氟磺酰胺。其中一些化合物的水平已在大气中测量到，但大多数化合物的浓度尚未检测到。显然，大气中挥发性前体的氧化作用会导致 PFA 的总负担增加，尽管这种情况发生的程度取决于化合物和环境，且难以准确评估。
