Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy; NatRisk Inter-Department Centre, University of Torino, Via L. da Vinci 44, 10095, Grugliasco (TO), Italy.
Water Res. 2016 Jan 1;88:235-244. doi: 10.1016/j.watres.2015.10.015. Epub 2015 Oct 23.
We studied the aquatic environmental fate of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA), a widespread sunscreen, to assess its environmental persistence and photoinduced transformation. Direct photolysis is shown to play a key role in phototransformation, and this fast process is expected to be the main attenuation route of OD-PABA in sunlit surface waters. The generation of transformation products (TPs) was followed via HPLC/HRMS. Five (or four) TPs were detected in the samples exposed to UVB (or UVA) radiation, respectively. The main detected TPs of OD-PABA, at least as far as HPLC-HRMS peak areas are concerned, would involve a dealkylation or hydroxylation/oxidation process in both direct photolysis and indirect phototransformation. The latter was simulated by using TiO2-based heterogeneous photocatalysis, involving the formation of nine additional TPs. Most of them resulted from the further degradation of the primary TPs that can also be formed by direct photolysis. Therefore, these secondary TPs might also occur as later transformation intermediates in natural aquatic systems.
我们研究了一种广泛使用的防晒霜 2-乙基己基 4-(二甲氨基)苯甲酸酯（OD-PABA）在水生环境中的归宿，以评估其环境持久性和光诱导转化。直接光解被证明在光转化中起着关键作用，这个快速过程预计将是 OD-PABA 在阳光照射的地表水的主要衰减途径。通过 HPLC/HRMS 跟踪转化产物（TPs）的生成。在暴露于 UVB（或 UVA）辐射的样品中分别检测到五个（或四个）TPs。OD-PABA 的主要检测到的 TPs，至少就 HPLC-HRMS 峰面积而言，涉及直接光解和间接光转化中的脱烷基化或羟化/氧化过程。后者通过使用基于 TiO2 的多相光催化来模拟，涉及形成另外九个 TPs。它们中的大多数是由直接光解也能形成的主要 TPs 进一步降解产生的。因此，这些二次 TPs 也可能作为天然水生系统中后续转化的中间产物出现。
