Per- and polyfluoroalkyl substances (PFAS) are being increasingly measured in water and wastewater due to emerging toxicity concerns and strict regulatory limits. Previous studies have filtered water samples to remove suspended solids before PFAS analysis. However, filtration may introduce negative bias to measured PFAS concentrations. Using a well-controlled syringe pump assembly, we evaluated retention of six perfluoroalkyl carboxylates, three perfluoroalkyl sulfonates, one fluorotelomer sulfonate, and two perfluorooctane sulfonamides by glass-fiber, glass-fiber cellulose acetate, nylon, polyethersulfone, polypropylene, polyvinylidene fluoride/ difluoride, and surfactant-free cellulose acetate filters. The impacts of water quality and operational parameters were also investigated for select filter types. We found that PFAS were retained on all filters, with the glass-fiber cellulose acetate filters demonstrating the lowest retention. For all filters, PFAS retention was linearly related to chain length and hydrophobicity above certain thresholds (i.e., log D higher than 1.5). Importantly, more PFAS were retained at low filtrate volumes, and ~ 30 mL filtrate was required before the retention efficiencies stabilized. Solution pH only affected the retention of perfluorooctane sulfonamides. Pore size (i.e., 0.20, 0.45, 0.70 µm), filtration rate (i.e., 0.5, 1.0 mL min⁻¹), and PFAS concentration (i.e., 10, 100 µg L⁻¹), did not exert major influences on PFAS retention. The presence of dissolved organic matter improved PFAS permeation. Based on the reported results, filtration introduces bias and is not recommended for sample pretreatment.

由于新出现的毒性问题和严格的监管限制，全氟烷基物质和多氟烷基物质 (PFAS) 在水和废水中的测量越来越多。先前的研究在 PFAS 分析之前过滤了水样以去除悬浮固体。然而，过滤可能会给测量的 PFAS 浓度带来负偏差。使用控制良好的注射泵组件，我们评估了玻璃纤维、玻璃纤维醋酸纤维素、尼龙、聚醚砜、聚丙烯、聚偏二氟乙烯/二氟乙烯对六种全氟烷基羧酸盐、三种全氟烷基磺酸盐、一种氟调聚物磺酸盐和两种全氟辛烷磺酰胺的保留和不含表面活性剂的醋酸纤维素过滤器。还针对选定的过滤器类型研究了水质和操作参数的影响。我们发现所有过滤器上都保留了 PFAS，其中玻璃纤维醋酸纤维素过滤器的保留率最低。对于所有过滤器，PFAS 截留与链长和疏水性在一定阈值以上（即，log D 高于 1.5）呈线性相关。重要的是，在低滤液体积下保留了更多的 PFAS，并且在保留效率稳定之前需要约 30 mL 的滤液。溶液 pH 值仅影响全氟辛烷磺酰胺的保留。孔径（即0.20、0.45、0.70 µm）、过滤速率（即0.5、1.0 mL min ⁻¹）和PFAS浓度（即10、100 µg L ⁻¹）对PFAS保留没有产生重大影响。溶解有机物的存在改善了 PFAS 的渗透性。根据报告的结果，过滤会引入偏差，不建议用于样品预处理。