Department of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States.
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.
Anal Chem. 2022 Oct 25;94(42):14537-14545. doi: 10.1021/acs.analchem.2c00916. Epub 2022 Oct 10.
We present a detailed molecular characterization of organophosphorus compounds in ambient organic aerosol influenced by wildfire smoke. Biomass burning organic aerosol (BBOA) is an important source of phosphorus (P) to surface waters, where even a small imbalance in the P flux can lead to substantial effects on water quality, such as eutrophication, algal blooms, and oxygen depletion. We aimed to exploit the ultrahigh resolving power, mass accuracy, and sensitivity of Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) to explore the molecular composition of an ambient BBOA sample collected downwind of Pacific Northwest wildfires. The 21-T FT-ICR MS yielded 10 533 distinct formulae, which included molecular species comprising C, H, O, and P with or without N, i.e., organophosphorus compounds that have long been quantified in wildfire smoke but have not yet been characterized at the molecular level. The lack of detailed molecular characterization of organophosphorus compounds in BBOA is primarily due to their inherently low concentrations in aerosols and poor ionization efficiency in complex mixtures. We demonstrate that the exceptional sensitivity of the 21-T FT-ICR MS allows qualitative analysis of a previously uncharacterized fraction of BBOA without its selective concentration from the organic matrix, exemplifying the need for ultrahigh-resolution tools for a more detailed and accurate molecular depiction of such complex mixtures.
我们对受野火烟雾影响的环境有机气溶胶中的有机磷化合物进行了详细的分子特征描述。生物质燃烧有机气溶胶（BBOA）是向地表水中提供磷（P）的重要来源，即使 P 通量的微小不平衡也会对水质产生重大影响，例如富营养化、藻类大量繁殖和缺氧。我们旨在利用傅里叶变换离子回旋共振质谱（FT-ICR MS）的超高分辨率、质量精度和灵敏度来探索在西北太平洋野火下风处采集的环境 BBOA 样本的分子组成。21-T FT-ICR MS 产生了 10533 个不同的公式，其中包括含有 C、H、O 和 P 的分子物种，以及含有或不含有 N 的分子物种，即长期以来在野火烟雾中定量的有机磷化合物，但尚未在分子水平上进行表征。BBOA 中有机磷化合物缺乏详细的分子特征描述主要是由于它们在气溶胶中的固有低浓度和在复杂混合物中的差电离效率。我们证明，21-T FT-ICR MS 的卓越灵敏度允许对以前未表征的 BBOA 部分进行定性分析，而无需从有机基质中选择性浓缩，这说明了需要超高效分辨率工具来更详细和准确地描述此类复杂混合物的分子。
