Herzsprung Peter, Kamjunke Norbert, Wilske Christin, Friese Kurt, Boehrer Bertram, Rinke Karsten, Lechtenfeld Oliver J, von Tümpling Wolf
UFZ - Helmholtz Centre for Environmental Research, Department Lake Research, Brückstraße 3a, Magdeburg D-39114, Germany.
UFZ - Helmholtz Centre for Environmental Research, Department River Ecology, Brückstraße 3a, Magdeburg D-39114, Germany.
Water Res. 2023 Apr 1;232:119672. doi: 10.1016/j.watres.2023.119672. Epub 2023 Jan 28.
The molecular composition of dissolved organic matter (DOM) is of relevance for global carbon cycling and important for drinking water processing also. The detection of variation of DOM composition as function of time and space from a methodological viewpoint is essential to observe DOM processing and was addressed so far. High resolution concerning DOM quality was achieved with Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS). However almost none of the existing FTICR-MS data sets were evaluated addressing the fate of single mass features / molecular formulas (MFs) abundance during experiments. In contrast to former studies we analyze the function of MF abundance of time and space for such MFs which are present in all samples and which were formerly claimed as recalcitrant in not all but a great number of studies. For the first time the reactivity of MFs was directly compared by their abundance differences using a simple equation, the relative intensity difference (δRI). Search strategies to find out the maximum δRI values are introduced. The corresponding MFs will be regarded as key MFs (KEY-MFs). In order to test this new approach data from a recent photo degradation experiment were combined with monitoring surveys conducted in two drinking water reservoirs. The δRI values varied over one order of magnitude (more than five-fold). MFs like CHO and CHO revealed high biogeochemical reactivity as photo products. Some of the KEY-MFs were identical with MFs identified as disinfection byproducts precursors in recent studies. Other KEY-MFs were oxygen-rich and relatively unsaturated (poly-phenol-like) and hence relevant to flocculation procedures.
溶解有机物（DOM）的分子组成与全球碳循环相关，对饮用水处理也很重要。从方法学角度检测DOM组成随时间和空间的变化对于观察DOM的处理过程至关重要，并且到目前为止已经得到了关注。通过傅里叶变换离子回旋共振质谱（FTICR-MS）实现了对DOM质量的高分辨率分析。然而，几乎没有现有FTICR-MS数据集针对实验过程中单个质量特征/分子式（MFs）丰度的变化情况进行评估。与以往研究不同，我们分析了所有样品中都存在的、在许多但并非所有研究中都被认为是难降解的MFs的丰度随时间和空间的变化情况。首次通过一个简单的方程——相对强度差异（δRI），利用MFs的丰度差异直接比较它们的反应活性。介绍了找出最大δRI值的搜索策略。相应的MFs将被视为关键MFs（KEY-MFs）。为了验证这种新方法，将最近一个光降解实验的数据与在两个饮用水水库进行的监测调查数据相结合。δRI值变化超过一个数量级（超过五倍）。像CHO和CHO这样的MFs作为光产物显示出高生物地球化学反应活性。一些KEY-MFs与近期研究中确定为消毒副产物前体的MFs相同。其他KEY-MFs富含氧且相对不饱和（类似多酚），因此与絮凝过程相关。
