Transformation Products of Tire Rubber Antioxidant 6PPD in Heterogeneous Gas-Phase Ozonation: Identification and Environmental Occurrence
Transformation Products of Tire Rubber Antioxidant 6PPD in Heterogeneous Gas-Phase Ozonation: Identification and Environmental Occurrence
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轮胎橡胶防老剂6PPD在非均相气相臭氧氧化中的转化产物：鉴定及环境发生
DOI：
10.1021/acs.est.2c08690
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发表时间：
2023
影响因子：
11.4
通讯作者：
Kolodziej, Edward P.
中科院分区：
文献类型：
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作者：
Zhao, Haoqi Nina;Hu, Ximin;Tian, Zhenyu;Gonzalez, Melissa;Rideout, Craig A.;Peter, Katherine T.;Dodd, Michael C.;Kolodziej, Edward P.
6PPD是一种轮胎橡胶抗氧剂，暴露在气相臭氧中会形成一种剧毒的苯醌转化产物(TP)-6PPDQ(6PPDQ)，因此会造成重大的生态风险。关于6PPD臭氧氧化产生的TPS的结构、反应机理和环境存在的重要数据空白。为了弥补这些数据空白，在24-168h内进行了6PPD的气相臭氧氧化，并用高分辨率质谱仪对臭氧氧化TPS进行了表征。提出了23个TPS的可能结构，其中5个随后进行了标准验证。与以前的研究结果一致，6PPDQ(C18H22N2O2)是6PPD臭氧氧化的主要总磷之一(∼的产率为1-19%)。值得注意的是，在6QDI(N-(1，3-dimethylbutyl)-N′-phenyl-p-quinonediimine)，的臭氧氧化过程中没有观察到6PPDQ，这表明6PPDQ的形成不是通过6QDI或相关的6QDI TPS进行的。其他主要的6PPD TPS包括多个C18H22N2O和C18H22N2O2异构体，推测为N-氧化物、N，N‘-二氧化物和邻苯二酚结构。经标准验证的轮胎胎面磨损颗粒物(TWP)甲醇萃取物中总浓度为130±3.2TWP/g，TWP渗滤液中总浓度为34±4μg/g-TWP，道路径流中总浓度为2700±1500 ng/L，小溪中总浓度为1900±1200 ng/L。这些数据表明，在受道路影响的环境中，6PPD TPS可能是一种重要且普遍存在的污染物类别。
6PPD, a tire rubber antioxidant, poses substantial ecological risks because it can form a highly toxic quinone transformation product (TP), 6PPD-quinone (6PPDQ), during exposure to gas-phase ozone. Important data gaps exist regarding the structures, reaction mechanisms, and environmental occurrence of TPs from 6PPD ozonation. To address these data gaps, gas-phase ozonation of 6PPD was conducted over 24–168 h and ozonation TPs were characterized using high-resolution mass spectrometry. The probable structures were proposed for 23 TPs with 5 subsequently standard-verified. Consistent with prior findings, 6PPDQ (C18H22N2O2) was one of the major TPs in 6PPD ozonation (∼1 to 19% yield). Notably, 6PPDQ was not observed during ozonation of 6QDI (N-(1,3-dimethylbutyl)-N′-phenyl-p-quinonediimine), indicating that 6PPDQ formation does not proceed through 6QDI or associated 6QDI TPs. Other major 6PPD TPs included multiple C18H22N2O and C18H22N2O2isomers, with presumptiveN-oxide,N,N′-dioxide, and orthoquinone structures. Standard-verified TPs were quantified in roadway-impacted environmental samples, with total concentrations of 130 ± 3.2 μg/g in methanol extracts of tire tread wear particles (TWPs), 34 ± 4 μg/g-TWP in aqueous TWP leachates, 2700 ± 1500 ng/L in roadway runoff, and 1900 ± 1200 ng/L in roadway-impacted creeks. These data demonstrate that 6PPD TPs are likely an important and ubiquitous class of contaminants in roadway-impacted environments.