Matsuda Fumio, Komori Shuka, Yamada Yuki, Hara Daiki, Okahashi Nobuyuki
Graduate School of Information Science and Technology, Osaka University, Osaka, Japan.
Osaka University Shimadzu Omics Innovation Research Laboratories, Osaka University, Osaka, Japan.
Mass Spectrom (Tokyo). 2022;11(1):A0106. doi: 10.5702/massspectrometry.A0106. Epub 2022 Dec 15.
In metabolomics studies using high-resolution mass spectrometry (MS), a set of product ion spectra is comprehensively acquired from observed ions using the data-dependent acquisition (DDA) mode of various tandem MS. However, especially for low-intensity signals, it is sometimes difficult to distinguish artifact signals from true fragment ions derived from a precursor ion. Inadequate precision in the measured / value is also one of the bottlenecks to narrowing down the candidate compositional formula. In this study, we report that averaging multiple product ion spectra can improve / precision as well as the reliability of fragment ions that are observed in such spectra. A graph-based method was applied to cluster a set of similar spectra from multiple DDA data files resulting in creating an averaged product-ion spectrum. The error levels for the / values declined following the central limit theorem, which allowed us to reduce the number of candidate compositional formulas. The improved reliability and precision of the averaged spectra will contribute to a more efficient annotation of product ion spectral data.
在使用高分辨率质谱（MS）的代谢组学研究中，利用各种串联质谱的数据依赖采集（DDA）模式从观测到的离子中全面获取一组产物离子谱。然而，特别是对于低强度信号，有时很难将伪信号与源自前体离子的真实碎片离子区分开来。测量的m/z值精度不足也是缩小候选组成式范围的瓶颈之一。在本研究中，我们报告称，对多个产物离子谱进行平均可以提高m/z精度以及在此类谱中观测到的碎片离子的可靠性。应用一种基于图的方法对来自多个DDA数据文件的一组相似谱进行聚类，从而生成平均产物离子谱。根据中心极限定理，m/z值的误差水平下降，这使我们能够减少候选组成式的数量。平均谱可靠性和精度的提高将有助于更高效地注释产物离子谱数据。
