Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, 1 Jan Smuts Ave, Braamfontein, Johannesburg, 2000, South Africa; Mpact Innovation, Research & Development, Devon Valley Road, Stellenbosch, 7600, South Africa.
Institute for Nanotechnology and Water Sustainability, College of Science, Engineering and Technology, University of South Africa, Florida Science Campus, 28 Pioneer Ave, Roodepoort, Johannesburg, 1709, South Africa.
Chemosphere. 2024 Sep;363:142904. doi: 10.1016/j.chemosphere.2024.142904. Epub 2024 Jul 19.
Non-targeted analysis and suspect screening of per- and polyfluoroalkyl substances (PFAS) in various matrices have gained traction with advancements in accurate mass analytical instruments. This study employed ultra-high performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry for PFAS suspect screening of paper grades used in the paper recycling chain. The samples were prepared using two extraction techniques; selective accelerated solvent extraction with weak anionic exchange solid-phase extraction and non-selective ultrasonic-assisted extraction. A suspect screening protocol was established to tentatively identify suspected PFAS against spectral databases using a systematic approach of peak filtering and study-specific thresholds for reporting, linked to a confidence level. The possible prevalence of previously unreported PFAS in several paper materials across the various collection sites in the paper recycling chain was inferred by the common detection of short-chain polyfluoroalkyl ketones and diketones in the paper recycling chain. The suspect screening tentatively identified 41 unique PFAS, with 3 common to both pre-treatment techniques. The detection of unique PFAS by the two sample pre-treatment techniques highlighted the significance of both selective and non-selective extraction in PFAS screening endeavours. Further, it showed the importance of understanding the acquisition mechanisms employed in mass spectrometry where data-dependent acquisition triggered fragmentation in certain identified compounds, and not in others. The tentatively identified PFAS indicated that there were several previously unreported PFAS in the paper recycling chain and that additional studies were required to investigate their abundance, possible persistence, bioaccumulation and toxicity, in relation to their functional groups and carbon chains.
非靶向分析和筛选各种基质中的全氟和多氟烷基物质 (PFAS) 随着精确质量分析仪器的进步而受到关注。本研究采用超高效液相色谱-四极杆轨道阱高分辨率质谱法对纸张回收链中使用的纸张等级进行 PFAS 筛选。这些样品使用两种提取技术进行制备；选择性加速溶剂萃取和弱阴离子交换固相萃取和非选择性超声辅助萃取。建立了一种筛选方案，通过使用峰过滤和与置信度相关的报告的特定于研究的阈值的系统方法，利用光谱数据库来临时识别疑似 PFAS。通过在纸张回收链中共同检测短链聚氟烷基酮和二酮，可以推断出在纸张回收链中的各个收集点的几种纸张材料中存在以前未报告的 PFAS 的可能性。筛选方案初步确定了 41 种独特的 PFAS，其中 3 种存在于两种预处理技术中。两种样品预处理技术对独特 PFAS 的检测突出了选择性和非选择性提取在 PFAS 筛选工作中的重要性。此外，它还表明了了解在质谱中采用的采集机制的重要性，其中数据依赖性采集在某些确定的化合物中引发了碎片化，而在其他化合物中则没有。初步确定的 PFAS 表明在纸张回收链中存在几种以前未报告的 PFAS，需要进一步研究以调查它们的丰度、可能的持久性、生物累积性和毒性，以及它们的官能团和碳链。
