Improved Dynamic Range, Resolving Power, and Sensitivity Achievable with FT-ICR Mass Spectrometry at 21 T Reveals the Hidden Complexity of Natural Organic Matter
Improved Dynamic Range, Resolving Power, and Sensitivity Achievable with FT-ICR Mass Spectrometry at 21 T Reveals the Hidden Complexity of Natural Organic Matter
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DOI：
10.1021/acs.analchem.2c02377
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发表时间：
2022-08-02
影响因子：
7.4
通讯作者：
McKenna, Amy M.
中科院分区：
文献类型：
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作者：
Bahureksa, William;Borch, Thomas;McKenna, Amy M.
傅里叶变换离子回旋共振质谱（FT-ICR MS）是目前唯一能够在元素组成归属水平上解析天然有机物分子复杂性的质谱分析仪。在这里，我们利用定制的21特斯拉混合线性离子阱/FT-ICR质谱仪的高动态范围、分辨率、抗峰值聚结性以及最大离子数和离子捕获持续时间，用于溶解有机物标准品（Suwanne River富里酸）。我们比较了峰拾取阈值（3 sigma，4 sigma，5 sigma和6 sigma）对元素组成分配数量，质量测量准确度和动态范围的影响，其中m/z 200-1200质量范围内的6.3 s瞬态包括迄今为止收集的最高分辨率宽带FT-ICR质谱。在36 ppb的均方根质量误差下，超过36，000个物种的信号幅度大于3 sigma，这是迄今为止报告的溶解有机物中识别出的最多物种。我们识别O-18和O-17同位素体，并在宽质量范围（高达tn/z 1000）内利用仅可由21 T FT-ICR MS实现的质量分辨能力（m/z 200时为3 000 000），并通过吸收模式数据处理将其提高约30%，从而解决了几个电子的等压重叠。元素组成独特的3西格玛跨越了广泛的组成范围内的芳香性没有检测到在更高的峰值采摘阈值。此外，我们利用21 T FT-ICR MS的高动态范围，为分析界提供广泛使用的参比标准品（SRFA）的分子目录，这些参比标准品是在迄今为止最高性能的质量分析仪上收集的，用于复杂混合物分析。该仪器免费提供给世界各地的科学家。
Fourier transform ion-cyclotron resonance mass spectrometry (FT-ICR MS) is the only mass analyzer that can resolve the molecular complexity of natural organic matter at the level of elemental composition assignment. Here, we leverage the high dynamic range, resolving power, resistance to peak coalescence, and maximum ion number and ion trapping duration in a custom built, 21 tesla hybrid linear ion trap /FT-ICR mass spectrometer for a dissolved organic matter standard (Suwanne River Fulvic Acid). We compare the effect of peak-picking threshold (3 sigma, 4 sigma, 5 sigma, and 6 sigma) on number of elemental composition assignments, mass measurement accuracy, and dynamic range for a 6.3 s transient across the mass range of m/z 200-1200 that comprises the highest achieved resolving power broadband FT-ICR mass spectrum collected to date. More than 36 000 species are assigned with signal magnitude greater than 3 sigma at root-mean-square mass error of 36 ppb, the most species identified reported to date for dissolved organic matter. We identify O-18 and O-17 isotopologues and resolve isobaric overlaps on the order of a few electrons across a wide mass range (up to tn/z 1000) leveraging mass resolving powers (3 000 000 at m/z 200) only achievable by 21 T FT-ICR MS and increased by similar to 30% through absorption mode data processing. Elemental compositions unique to the 3 sigma span a wide compositional range of aromaticity not detected at higher peak-picking thresholds. Furthermore, we leverage the high dynamic range at 21 T FT-ICR MS to provide a molecular catalogue of a widely utilized reference standard (SRFA) to the analytical community collected on the highest performing mass analyzer for complex mixture analysis to date. This instrument is available free of charge to scientists worldwide.