The occurrence and risk of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q), derived from the oxidation of the tire antidegradant 6PPD, has raised significant concern since it was found to cause acute mortality in coho salmon when exposed to urban runoff. Given the short half-life period and low solubility of 6PPD-Q, reliable in situ measurement techniques are required to accurately understand its occurrence and behaviour in aquatic environments. Here, using the diffusive gradients in thin-films (DGT) method with HLB as a binding agent, we developed a new methodology to measure 6PPD-Q in urban waters. 6PPD-Q was rapidly and strongly adsorbed on the HLB-binding gel and was efficiently extracted using organic solvents. The HLB-DGT accumulated 6PPD-Q linearly for >7 d and its performance was not significantly affected by pH (6.5–8.5), ionic strength (0.0001–0.5 M) or dissolved organic matter (0–20 mg L−1). Field evaluation of the DGT method demonstrated its effectiveness in urban runoff, detecting 6PPD-Q levels of 15.8–39.5 ng L−1 in rivers. In snowmelt, DGT detected 6PPD-Q levels of 210 ng L−1 which is two times higher than the value obtained by grab sampling. 6PPD-Q levels were much higher in snowmelt than those in rivers. This indicates that snowfall constitutes an important transport pathway for 6PPD-Q and that DGT effectively captured the fraction continuously released from dust particles in the snow samples. 6PPD-Q posed a substantial risk to migratory fish in urban waters, and its release from tire wear particles requires further investigation. This study is the first to develop a DGT-based method for 6PPD-Q determination in urban waters, and the method can ensure an accurate measurement of the release of 6PPD-Q to the environment, particularly in rainfall or snowmelt, important pathways for its entry into the aquatic environment.

中文翻译：

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薄膜中扩散梯度的开发与应用在城市水域 6PPD-醌原位监测中的应用


由轮胎抗降解剂 6PPD 氧化衍生的 N-（1,3-二甲基丁基）-N′-苯基-对苯二胺-醌 （6PPD-Q） 的发生和风险引起了严重关注，因为它被发现在暴露于城市径流时会导致银大麻哈鱼急性死亡。鉴于 6PPD-Q 的半衰期短且溶解度低，需要可靠的原位测量技术来准确了解其在水生环境中的发生和行为。在这里，使用以 HLB 作为结合剂的薄膜扩散梯度 （DGT） 方法，我们开发了一种新方法来测量城市水域中的 6PPD-Q。6PPD-Q 快速而强烈地吸附在 HLB 结合凝胶上，并使用有机溶剂进行有效萃取。HLB-DGT 在 >7 d 内线性积累 6PPD-Q，其性能不受 pH 值 （6.5-8.5）、离子强度 （0.0001-0.5 M） 或溶解有机物 （0-20 mg L-1） 的显著影响。DGT 方法的现场评估证明了它在城市径流中的有效性，检测到河流中 6PPD-Q 水平为 15.8-39.5 ng L-1。在融雪中，DGT 检测到 6PPD-Q 水平为 210 ng L-1，比取样获得的值高出两倍。6融雪中的 PPD-Q 水平远高于河流中的水平。这表明降雪构成了 6PPD-Q 的重要传输途径，并且 DGT 有效地捕获了雪样中尘埃颗粒连续释放的分数。6PPD-Q 对城市水域的洄游鱼类构成重大风险，其从轮胎磨损颗粒中释放出来需要进一步调查。 本研究首次开发了基于 DGT 的 6PPD-Q 测定方法，该方法可确保准确测量 6PPD-Q 释放到环境中的情况，特别是在降雨或融雪中，这是其进入水生环境的重要途径。