A prior method of mass labeling ketone-/aldehyde-containing species in natural dissolved organic matter (DOM) is further developed and applied. This application involved the treatment of Suwannee River fulvic acid (SRFA) with increasing concentrations of sodium borodeuteride (NaBD4), followed by detection of reduced species via negative mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR MS). The extent of reduction, as determined by ESI FTICR MS, resulting from increasing concentrations of NaBD4 correlated well with changes in the absorption and emission spectra of the corresponding untreated and borodeuteride-reduced samples, providing evidence that ketone/aldehyde functional groups contribute substantially to the bulk optical properties of SRFA. Furthermore, the differences in the reactivity and abundance of ketone-/aldehyde-containing species for various regions in Van Krevelen plots were revealed, thus showing how this mass labeling method can be used to provide more detailed structural information about components within complex DOM samples than that provided by the determination and analysis of molecular formulae alone. Graphical abstract.

中文翻译：

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超高分辨率质谱和氘标记显示了酮/醛类化合物对Suwannee River黄腐酸的组成和光学性质的贡献。

进一步开发和应用了在天然溶解的有机物（DOM）中大规模标记含酮/醛类物质的现有方法。该应用涉及用浓度增加的硼氢化氘（NaBD4）处理Suwannee河富叶酸（SRFA），然后通过负模式电喷雾电离傅立叶变换离子回旋共振质谱（ESI FTICR MS）检测还原物种。由ESI FTICR MS确定的，由NaBD4浓度增加引起的还原程度与相应的未处理和硼氘化物还原的样品的吸收和发射光谱的变化密切相关，从而提供了酮/醛官能团对SRFA的整体光学性质。此外，揭示了Van Krevelen图中各个区域的含酮/醛物种的反应性和丰度的差异，从而表明了这种质量标记方法如何可用于提供有关复杂DOM样品中组分的比提供的更详细的结构信息仅通过分子式的确定和分析即可。图形概要。