Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada.
Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada; Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
Sci Total Environ. 2022 Dec 1;850:157898. doi: 10.1016/j.scitotenv.2022.157898. Epub 2022 Aug 8.
Polar organic chemical integrative sampler (POCIS) contains sorbent, which is typically enclosed between two polyethersulfones (PES) membranes. A significant PES uptake is reported for many contaminants, yet, aqueous concentration is mainly correlated with the sorbent uptake using first-order kinetics. Under high PES sorption, the first-order kinetics often provide erroneous sampling rate for the sorbent phase due to increased membrane resistance. This work evaluated the uptake of four high PES sorbing chemicals, i.e., three Cl- and CH-substituted nitrobenzenes and one chlorinated aniline using POCIS and the potential of a single-phase PES sampler using laboratory experiments. POCIS calibration results demonstrated that both sorbent and membrane had similar affinity for the target compounds. A rapid PES sorption occurred in the earlier days (<7 days) followed by a gradual increase in the PES phase concentration (equilibrium not achieved after 60 days). Especially, the membrane was the primary sink for 3,4-dichloroaniline and 3,4-dichloronitrobenzene for up to 14 and 31 days, respectively. On the other hand, the single-phase PES sampler showed similar mass uptake as POCIS and reached equilibrium within 19 days under static condition, indicating its potential suitability in the equilibrium regime. PES-water partition coefficient of the target compounds was between 1.2 and 6.5 L/g. Finally, we present a poly-parameter linear-free energy relationship (pp-LFER) using published data to predict the PES-water partition coefficients. The pp-LFER models showed moderate predictability as indicated by R values between 0.7 and 0.9 for both internal and external data set consisting of a wide range of hydrophobic and hydrophilic compounds (-0.1 ≤ logK ≤ 7.4). The proposed pp-LFER model can be used to screen high PES-sorbing chemicals to increase the reliability and accuracy of aqueous concentration prediction from POCIS sampling and to select the most appropriate sampling approach for new compounds.
极性有机化学整合采样器（POCIS）包含吸附剂，通常夹在两个聚醚砜（PES）膜之间。据报道，许多污染物对 PES 的吸收量很大，但水相中浓度主要与吸附剂的吸收量呈一级动力学关系。在高 PES 吸附的情况下，由于膜阻力的增加，一级动力学通常会导致吸附剂相的采样速率出现错误。本研究使用 POCIS 和实验室实验评估了四种高 PES 吸附化学品（即三个 Cl-和 CH 取代的硝基苯和一个氯代苯胺）的吸收情况，以及单相 PES 采样器的潜力。POCIS 校准结果表明，吸附剂和膜对目标化合物具有相似的亲和力。在早期（<7 天）迅速发生 PES 吸附，随后 PES 相浓度逐渐增加（60 天后未达到平衡）。特别是，在长达 14 天和 31 天的时间里，膜是 3,4-二氯苯胺和 3,4-二氯硝基苯的主要吸收剂。另一方面，在静态条件下，单相 PES 采样器的质量吸收与 POCIS 相似，在 19 天内达到平衡，表明其在平衡条件下具有潜在的适用性。目标化合物的 PES-水分配系数在 1.2 到 6.5 L/g 之间。最后，我们使用已发表的数据提出了一个多参数线性自由能关系（pp-LFER），以预测 PES-水分配系数。pp-LFER 模型的预测能力适中，内部和外部数据集的 R 值均在 0.7 到 0.9 之间，数据集包含广泛的疏水性和亲水性化合物（-0.1 ≤ logK ≤ 7.4）。所提出的 pp-LFER 模型可用于筛选高 PES 吸附化学品，以提高 POCIS 采样的水相中浓度预测的可靠性和准确性，并为新化合物选择最合适的采样方法。
