CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China; Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Environ Int. 2024 Sep;191:109004. doi: 10.1016/j.envint.2024.109004. Epub 2024 Sep 11.
The widespread occurrence of N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q) in aquatic environments and its hazards to aquatic species underscore the necessity of comprehending its environmental fate. Here, we investigated the transformation from 6PPD to 6PPD-Q and the attenuation of 6PPD-Q in surface water under natural conditions. Contrary to prior findings, this work revealed that 6PPD-Q and its precursor 6PPD-OH/6PPD-(OH), were not detected through target analysis and suspect screening during 6PPD transformation in the surface water under the natural conditions. 6PPD-Q predominantly accumulated in TWPs in ambient atmosphere with 1.28 % mass yield from the 6PPD dissipation. Subsequently, 6PPD-Q was eluted from TWPs and released to the water environment. The investigation on the natural attenuation of 6PPD-Q in the surface water demonstrated that direct and indirect photolysis facilitated the rapid dissipation of 6PPD-Q with a half-life of 2.57 h. Utilizing the liquid chromatography high resolution mass spectrometry (LC-HRMS), including both time of flight (TOF) MS and Orbitrap MS, twelve novel transformation products (TPs) of 6PPD-Q were identified by using a comprehensive non-targeted screening strategy. The results from two dimensions gas chromatography (GC×GC) TOF-MS revealed additional two TPs. Based on the molecular structure of TPs, four major pathways of 6PPD-Q attenuation were proposed, including bond cleavage, hydroxylation, quinone cleavage and rearrangement. All TPs were predicted to exhibit lower toxicity, indicating the natural attenuation of 6PPD-Q reduced its toxicity and potential environmental risks. This study provides crucial insights into the environmental fate of 6PPD-Q, highlighting the significance of understanding both its formation from 6PPD and its subsequent attenuation processes under natural conditions.
N-(1,3-二甲基丁基)-N'-苯基-对苯二胺醌（6PPD-Q）广泛存在于水生环境中，对水生生物具有危害性，因此必须了解其环境归宿。本研究在自然条件下，考察了 6PPD 向 6PPD-Q 的转化及其在地表水中的衰减。与以往的研究结果不同，本研究通过目标分析和可疑筛选发现，在自然条件下，6PPD 在地表水中的转化过程中，未检测到 6PPD-Q 及其前体 6PPD-OH/6PPD-(OH)。6PPD-Q 主要在环境大气中的 TWPs 中积累，其质量产率为 1.28%，来自 6PPD 的耗散。随后，6PPD-Q 从 TWPs 中洗脱并释放到水环境中。本研究还考察了 6PPD-Q 在地表水中的自然衰减，结果表明，直接和间接光解促进了 6PPD-Q 的快速消解，半衰期为 2.57 h。利用包括飞行时间（TOF）质谱和轨道阱质谱在内的液相色谱高分辨质谱（LC-HRMS），采用全面的非靶向筛选策略，共鉴定出 6PPD-Q 的 12 种新转化产物（TPs）。二维气相色谱（GC×GC）TOF-MS 的结果显示，还存在另外两种 TPs。基于 TPs 的分子结构，提出了 6PPD-Q 衰减的四条主要途径，包括键断裂、羟化、醌断裂和重排。所有 TPs 均被预测具有较低的毒性，表明 6PPD-Q 的自然衰减降低了其毒性和潜在的环境风险。本研究为 6PPD-Q 的环境归宿提供了重要的见解，强调了了解 6PPD 形成及其在自然条件下后续衰减过程的重要性。
