Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada.
Environ Sci Technol. 2023 Jun 27;57(25):9224-9233. doi: 10.1021/acs.est.3c00809. Epub 2023 Jun 9.
The use of passive air samplers (PAS) for semi-volatile organic compounds (SVOCs) continues to expand. To advance quantitative understanding of uptake kinetics, we calibrated the XAD-PAS, using a styrene-divinylbenzene sorbent, through a year-long side-by-side deployment with an active sampler. Twelve XAD-PASs, deployed in June 2020, were retrieved at 4-week intervals, while gas phase SVOCs were quantified in 48 consecutive week-long active samples taken from June 2020 to May 2021. Consistent with XAD's high uptake capacity, even relatively volatile SVOCs, such as hexachlorobutadiene, displayed linear uptake throughout the entire deployment. Sampling rates (SRs) range between 0.1 and 0.6 m day for 26 SVOCs, including brominated flame retardants, organophosphate esters, and halogenated methoxylated benzenes. SRs are compared with experimental SRs reported previously. The ability of the existing mechanistic uptake model PAS-SIM to reproduce the observed uptake and SRs was evaluated. Agreement between simulated and measured uptake curves was reasonable but varied with compound volatility and the assumed stagnant air layer boundary thickness. Even though PAS-SIM succeeds in predicting the SR range for the studied SVOCs, it fails to capture the volatility dependence of the SR by underestimating the length of the linear uptake period and by failing to consider the kinetics of sorption.
被动空气采样器（PAS）在半挥发性有机化合物（SVOCs）的应用持续扩大。为了深入了解其吸收动力学，我们使用苯乙烯-二乙烯基苯吸附剂对 XAD-PAS 进行了校准，方法是将其与主动采样器进行长达一年的并排部署。2020 年 6 月部署了 12 个 XAD-PAS，每 4 周取回一次，同时在 2020 年 6 月至 2021 年 5 月期间，连续 48 周对气相 SVOCs 进行了定量分析。与 XAD 高吸收能力一致，即使是相对挥发性的 SVOCs，如六氯丁二烯，在整个部署过程中也表现出线性吸收。26 种 SVOCs 的采样速率（SR）范围在 0.1 到 0.6 m 天之间，包括溴化阻燃剂、磷酸酯和卤代甲氧基苯。将 SR 与之前报道的实验 SR 进行了比较。评估了现有的机制吸收模型 PAS-SIM 再现观察到的吸收和 SR 的能力。模拟和测量的吸收曲线之间的一致性是合理的，但随化合物挥发性和假设的停滞空气层边界厚度而变化。尽管 PAS-SIM 成功地预测了研究的 SVOCs 的 SR 范围，但它通过低估线性吸收期的长度以及未能考虑吸附动力学来无法捕捉到 SR 的挥发性依赖性。
