Sakas Justinas, Kitson Ezra, Bell Nicholle G A, Uhrín Dušan
EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Rd, Edinburgh EH9 3FJ, U.K.
Anal Chem. 2024 May 28;96(21):8263-8272. doi: 10.1021/acs.analchem.3c03888. Epub 2024 May 9.
FT-ICR MS and NMR analysis of an isotopically labeled complex mixture of water disinfection byproducts formed by chloramine disinfection of model phenolic acids is described. A new molecular formula assignment procedure using the CoreMS Python library able to assign isotopically enriched formulas is proposed. Statistical analysis of the assigned formulas showed that the number of compounds, the diversity of the mixture, and the chlorine count increase during the chloramination reaction. The complex reaction mixture was investigated as a network of reactions using PageRank and Reverse PageRank algorithms. Independent of the MS signal intensities, the PageRank algorithm calculates the formulas with the highest probability at convergence of the reaction; these were chlorinated and nitrated derivatives of the starting materials. The Reverse PageRank revealed that the most probable chemical transformations in the complex mixture were chlorination and decarboxylation. These agree with the data obtained from INADEQUATE NMR spectra and literature data, indicating that this approach could be applied to gain insight into reactions pathways taking place in complex mixtures without any prior knowledge.
描述了对通过氯胺对模型酚酸进行消毒形成的水消毒副产物的同位素标记复杂混合物进行傅里叶变换离子回旋共振质谱（FT-ICR MS）和核磁共振（NMR）分析。提出了一种使用CoreMS Python库的新分子式分配程序，该程序能够分配同位素富集的分子式。对分配的分子式进行统计分析表明，在氯胺化反应过程中，化合物的数量、混合物的多样性和氯含量都会增加。使用PageRank和反向PageRank算法将复杂反应混合物作为反应网络进行研究。与MS信号强度无关，PageRank算法在反应收敛时计算概率最高的分子式；这些是起始原料的氯化和硝化衍生物。反向PageRank表明，复杂混合物中最可能的化学转化是氯化和脱羧。这些与从不充足的NMR光谱获得的数据和文献数据一致，表明这种方法可用于在没有任何先验知识的情况下深入了解复杂混合物中发生的反应途径。
