Inrae, UR EABX, 50 avenue de Verdun, 33612 Cestas, France.
Inrae, UR EABX, 50 avenue de Verdun, 33612 Cestas, France.
Sci Total Environ. 2023 Apr 15;869:161720. doi: 10.1016/j.scitotenv.2023.161720. Epub 2023 Jan 20.
The Polar Organic Chemical Integrative Samplers (POCIS) is the most widely used passive sampler for hydrophilic compounds, but unsuitable for certain ionic organic contaminants. The Diffusive Gradient in Thin-Film technique (o-DGT) has shown positive results for both ionic and hydrophilic compounds. However, a calibration step is now needed to evaluate kinetic constant of accumulation for a wide range of molecules. In this study, o-DGT and POCIS were compared for the sampling of three families of micropollutants of potential risk to aquatic environments: 53 pesticides, 36 pharmaceuticals and 20 hormones. A calibration experiment was conducted to compare the kinetic models and constants from a scientific and practical perspective. The results are discussed in a single table that summarizes the performance of both passive samplers for the 109 compounds of interest. The advantage of o-DGT is that it allows linear accumulation for 72 compounds versus only 33 with POCIS. The mean times to equilibrium obtained with o-DGT are higher than those obtained with POCIS. These results confirm that the presence of a diffusion gel delays the achievement of equilibrium during compound accumulation. Therefore, o-DGT can be considered for situations where POCIS cannot be used due to non-linear accumulation over a typical 14-day deployment period. However, overall sampling rates and mass transfer coefficients also appear reduced with o-DGT, which is explained by the smaller exchange surface area, as well as the consideration of an additional diffusive layer in this device. This paper also showed that the most appropriate membrane to sample polar compounds with o-DGT was a polyethersulfone polymer with a pore size of 5 μm.
极性有机化学整合采样器（POCIS）是最广泛用于亲水性化合物的被动采样器，但不适合某些离子有机污染物。薄膜扩散梯度技术（o-DGT）已被证明对离子和亲水性化合物都有积极的效果。然而，现在需要进行校准步骤来评估广泛分子的积累动力学常数。在这项研究中，o-DGT 和 POCIS 被用于采样三种对水生环境有潜在风险的微污染物家族：53 种农药、36 种药物和 20 种激素。进行了校准实验，从科学和实践的角度比较了动力学模型和常数。结果在一个表格中进行了讨论，该表格总结了两种被动采样器对 109 种感兴趣化合物的性能。o-DGT 的优势在于它允许 72 种化合物线性积累，而 POCIS 只能允许 33 种化合物线性积累。用 o-DGT 获得的平衡时间平均值高于用 POCIS 获得的平衡时间平均值。这些结果证实，扩散凝胶的存在会在化合物积累过程中延迟达到平衡。因此，o-DGT 可用于由于在典型的 14 天部署期间非线性积累而无法使用 POCIS 的情况。然而，o-DGT 的总体采样速率和质量传递系数似乎也降低了，这是由于其交换表面积较小，以及在该装置中考虑了额外的扩散层所致。本文还表明，o-DGT 最适合采样极性化合物的膜是聚醚砜聚合物，其孔径为 5μm。
