Identification of Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass Spectrometry (TOFMS)
Identification of Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass Spectrometry (TOFMS)
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DOI：
10.1021/acs.est.5b01215
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发表时间：
2015-10-06
影响因子：
11.4
通讯作者：
Ball, Carol
中科院分区：
文献类型：
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作者：
Strynar, Mark;Dagnino, Sonia;Ball, Carol
最近对接触、毒性和风险的科学审查和关注促使国际监管努力，减少或消除了各种产品和废物流中的某些全氟化合物。一些制造商已开始生产较短链的全氟和多氟化合物，试图减少在人类和野生动物中的生物累积潜力。这些新化合物中的一些含有中心醚氧或传统全氟结构的其他微小修改。目前，在同行评审文献中发表的关于这些“替代化学品”的信息非常有限。在这项研究中，我们使用了飞行时间质谱检测器（LC-ESI-TOFMS），以确定从历史全氟化合物污染的地点收集的天然沃茨中的氟化合物。我们发现化学品的工作流程包括地表水的顺序采样以识别潜在来源，非靶向TOFMS分析，样品的分子特征提取（MFE），以及对具有源输入的样品的独特特征进行评估。具体而言，化合物通过以下方法初步鉴定：（I）准确测定来自源内碰撞诱导解离（CID）的母体和/或相关加合物和片段的质量，（2）深入评价分析期间形成的源内加合物，以及（3）可用真实标准品进行确认。我们观察到同源系列中的化合物组，其不同之处在于CF2（m/z 49.9968）或CF2 O（m/z 65）的倍数。9917）。对每个系列中的化合物进行色谱分离，并在分析过程中产生相当的片段和加合物。我们使用这种方法在美国北卡罗来纳州的地表水中检测到12种新的全氟烷基醚羧酸和磺酸。一个关键的证据是发现了精确的源内n-聚体形成质量（H+和Na+），m/z为21.9819，对应于质子化和钠化二聚体之间的质量差。
Recent scientific scrutiny and concerns over exposure, toxicity, and risk have led to international regulatory efforts resulting in the reduction or elimination of certain perfluorinated compounds from various products and waste streams. Some manufacturers have started producing shorter chain per- and polyfluorinated compounds to try to reduce the potential for bioaccumulation in humans and wildlife. Some of these new compounds contain central ether oxygens or other minor modifications of traditional perfluorinated structures. At present, there has been very limited information published on these "replacement chemistries" in the peer-reviewed literature. In this study we used a time-of-flight mass spectrometry detector (LC-ESI-TOFMS) to identify fluorinated compounds in natural waters collected from locations with historical perfluorinated compound contamination. Our workflow for discovery of chemicals included sequential sampling of surface water for identification of potential sources, nontargeted TOFMS analysis, molecular feature extraction (MFE) of samples, and evaluation of features unique to the sample with source inputs. Specifically, compounds were tentatively identified by (I) accurate mass determination of parent and/or related adducts and fragments from in-source collision-induced dissociation (CID), (2) in-depth evaluation of in-source adducts formed during analysis, and (3) confirmation with authentic standards when available. We observed groups of compounds in homologous series that differed by multiples of CF2 (m/z 49.9968) or CF2O (m/z 65. 9917). Compounds in each series were chromatographically separated and had comparable fragments and adducts produced during analysis. We detected 12 novel perfluoroalkyl ether carboxylic and sulfonic acids in surface water in North Carolina,USA using this approach. A key piece of evidence was the discovery of accurate mass in-source n-mer formation (H+ and Na+) differing by m/z 21.9819, corresponding to the mass difference between the protonated and sodiated dimers.