Abiotic oxidative transformation of 6-PPD and 6-PPD quinone from tires and occurrence of their products in snow from urban roads and in municipal wastewater

The antiozonant N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6-PPD) is added to tires to increase their lifetime and is emitted with tire and road wear particles into the environment. Recently, one of its transformation products (TPs), 6-PPD quinone (6-PPDQ), has gained attention due to its toxicity towards coho salmon. In this study, the abiotic oxidative transformation of 6-PPD is investigated by a series of ozonation experiments in the lab followed by analysis of TPs using liquid chromatography-high resolution-mass spectrometry (LC-HRMS). A total of 38 TPs were detected and tentatively identified, which were formed either directly from 6-PPD or via 6-PPDQ as intermediate. A suspect screening by…