Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
Ecotoxicol Environ Saf. 2020 Oct 1;202:110891. doi: 10.1016/j.ecoenv.2020.110891. Epub 2020 Jun 24.
Organophosphate ester contaminants, including organophosphate pesticides (OPPs) and organophosphate flame retardants (OPFRs) are ubiquitous in surface water and pose a significant risk to aquatic organisms, thus it is important to develop effective methods for long-term monitoring of these emerging compounds. Polar organic chemical integrative sampler (POCIS) has become a promising monitoring tool for waterborne contaminants, yet recent studies found that the commonly used polyethersulfone (PES) membrane strongly sorbed some moderately hydrophobic compounds, resulting in long lag-phase for chemical accumulation in POCIS. In the present study, 0.45-μm nylon membranes was selected as POCIS diffusion-limiting membrane to design a new POCIS-Nylon configuration for analyzing moderately hydrophobic OPPs and OPFRs in water. The POCIS-Nylon had negligible lag-phase due to low sorption of OPPs and OPFRs to nylon membrane. Meanwhile, linear accumulation time and sensitivity for target contaminants using POCIS-Nylon retained similar to the traditional POCIS. Water velocity and chemical concentration had little impact on sampling rate (R), validating that the POCIS-Nylon was suitable for various water conditions. Finally, the occurrence of OPPs and OPFRs in urban waterways of Guangzhou, China was evaluated using the POCIS-Nylon with R values that were calibrated in the laboratory. The average concentration of OPPs was 4.97 ± 1.35 ng/L (range: 2.64 ± 1.28-6.54 ± 0.18 ng/L) and the average concentration of OPFRs was 400 ± 88 ng/L (range: 316 ± 24-615 ± 36 ng/L) across nine sampling sites. The present study provides a way to resolve the inherent challenge of accumulating hydrophobic substances by POCIS.
有机磷酯污染物，包括有机磷农药 (OPPs) 和有机磷阻燃剂 (OPFRs)，普遍存在于地表水，对水生生物构成重大风险，因此开发这些新兴化合物的长期有效监测方法非常重要。极性有机化学整合采样器 (POCIS) 已成为一种有前途的水污染物监测工具，但最近的研究发现，常用的聚醚砜 (PES) 膜对一些中等疏水性化合物具有很强的吸附性，导致 POCIS 中化学物质的积累存在较长的滞后期。在本研究中，选择 0.45-μm 尼龙膜作为 POCIS 扩散限制膜，设计了一种新的 POCIS-尼龙构型，用于分析水中的中等疏水性 OPPs 和 OPFRs。由于尼龙膜对 OPPs 和 OPFRs 的吸附性低，POCIS-尼龙的滞后期可忽略不计。同时，使用 POCIS-尼龙的目标污染物的线性积累时间和灵敏度与传统 POCIS 相似。水样流速和化学浓度对采样速率 (R) 的影响较小，这验证了 POCIS-尼龙适用于各种水质条件。最后，使用在实验室中校准的 POCIS-Nylon 评估了中国广州城市水道中 OPPs 和 OPFRs 的存在情况，实验室校准的 R 值。OPPs 的平均浓度为 4.97 ± 1.35 ng/L（范围：2.64 ± 1.28-6.54 ± 0.18 ng/L），OPFRs 的平均浓度为 400 ± 88 ng/L（范围：316 ± 24-615 ± 36 ng/L），共 9 个采样点。本研究为解决 POCIS 积累疏水性物质的固有挑战提供了一种方法。
