School of Agriculture Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia.
School of Agriculture Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia; CSIRO Land and Water, PMB 2, Glen Osmond, SA, 5064, Australia.
Chemosphere. 2019 May;222:671-678. doi: 10.1016/j.chemosphere.2019.01.096. Epub 2019 Jan 18.
Measurement and reporting of concentrations of contaminants of emerging concern such as per- and polyfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA), is an integral part of most investigations. Occurrence of sorption losses of PFAS analytes onto particular laboratory-ware (e.g. glass containers) has been suggested in the published literature but has not been investigated in detail. We examined sorption losses from aqueous PFOA solutions in contact with different commonly-used materials in filter units and centrifuge tubes (glass and plastics). Sorption of PFOA onto different filter membrane types ranged from 21-79% indicating that filtration can introduce a major source of error in PFOA analysis; pre-treatment of filter membranes with phosphate or methanol solutions did not improve PFOA recovery. Substantial adsorption of PFOA was also observed on tubes made from polypropylene (PP), polystyrene (PS), polycarbonate (PC), and glass where losses observed were between 32-45%, 27-35%, 16-31% and 14-24%, respectively. Contrary to suggestions in the literature, our results indicated that the greatest sorption losses for PFOA occurred on PP, whereas losses on glass tubes were much lower. Variations in ionic strength and pH did not greatly influence PFOA recovery. When PFOA concentrations were increased, the percent recovery of PFOA increased, indicating that binding sites on tube-walls were saturable. This study draws attention towards analytical bias that can occur due to sorption losses during routine procedures, and highlights the importance of testing the suitability of chosen laboratory-ware for specific PFAS analytes of interest prior to experimental use.
测量和报告新兴关注污染物（如全氟和多氟烷基物质（PFASs），包括全氟辛酸（PFOA））的浓度是大多数研究的一个组成部分。已经在已发表的文献中提出了 PFAS 分析物在特定实验室器皿（例如玻璃容器）上发生吸附损失的情况，但尚未进行详细研究。我们研究了在过滤单元和离心管（玻璃和塑料）中与不同常用材料接触的水溶液中 PFOA 的吸附损失。PFOA 对不同滤膜类型的吸附率从 21-79%不等，这表明过滤可能会给 PFOA 分析带来主要的误差源；用磷酸盐或甲醇溶液预处理滤膜并不能提高 PFOA 的回收率。我们还观察到，在由聚丙烯（PP）、聚苯乙烯（PS）、聚碳酸酯（PC）和玻璃制成的管中，PFOA 的吸附量也很大，观察到的损失分别为 32-45%、27-35%、16-31%和 14-24%。与文献中的建议相反，我们的结果表明，PP 对 PFOA 的吸附损失最大，而玻璃管的损失要低得多。离子强度和 pH 的变化并没有对 PFOA 的回收率有很大影响。当 PFOA 浓度增加时，PFOA 的回收率增加，这表明管壁上的结合位点是可饱和的。这项研究引起了人们对由于常规程序中吸附损失而可能导致的分析偏差的关注，并强调了在实验前测试所选实验室器皿对特定感兴趣的 PFAS 分析物的适用性的重要性。
