Simultaneous screening of targeted and non-targeted contaminants using an LC-QTOF-MS system and automated MS/MS library searching
Simultaneous screening of targeted and non-targeted contaminants using an LC-QTOF-MS system and automated MS/MS library searching
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DOI：
10.1002/jms.3428
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发表时间：
2014-09-01
影响因子：
2.3
通讯作者：
Ulaszewska, M. M.
中科院分区：
文献类型：
--
作者：
Herrera-Lopez, S.;Hernando, M. D.;Ulaszewska, M. M.
同时使用飞行时间质谱进行高分辨率全扫描和串联质谱（MS/MS）分析，为不断增长的回顾性和非目标数据分析需求提供了答案。这种分析结合光谱库搜索是一种很有前途的小分子靶向和非靶向筛选工具。虽然串联质谱库的化合物种类有了很大的扩展，但谱数据的非均质性给谱库的有效利用带来了很大的挑战。可用LC-MS/MS库的性能评估将显著提高搜索结果的可信度。本工作旨在评估MS/MS模式的波动，峰强度分布以及质量精度测量，从而符合离子比和质量误差标准的性能，作为痕量目标和非目标污染物识别过程的原则。矩阵效应和超痕量浓度水平（从50ngl（-1）到1000ngl(-1)）被评估为光谱匹配性能不准确的潜在来源。筛选了矩阵匹配样本和真实样本，以证明其适用性。通过人工审查数据和应用离子比和ppm误差标准，得到假阴性；当使用内部库时，这一数字减少，而使用在线MS/MS数据库时，100%的阳性样本被发现。根据我们的经验，光谱中峰的强度与浓度效应和矩阵复杂度高度相关。反过来，在痕量浓度和不同基质中获得的光谱分析结果在提供正确和可靠的鉴定方面具有更好的性能。版权所有：John Wiley & Sons， Ltd。
Simultaneous high-resolution full-scan and tandem mass spectrometry (MS/MS) analysis using time of flight mass spectrometry brings an answer for increasing demand of retrospective and non-targeted data analysis. Such analysis combined with spectral library searching is a promising tool for targeted and untargeted screening of small molecules. Despite considerable extension of the panel of compounds of tandem mass spectral libraries, the heterogeneity of spectral data poses a major challenge against the effective usage of spectral libraries. Performance evaluation of available LC-MS/MS libraries will significantly increase credibility in the search results. The present work was aimed to evaluate fluctuation of MS/MS pattern, in the peak intensities distribution together with mass accuracy measurements, and in consequence, performance compliant with ion ratio and mass error criteria as principles in identification processes for targeted and untargeted contaminants at trace levels. Matrix effect and ultra-trace levels of concentration (from 50ngl(-1) to 1000ngl(-1)) were evaluated as potential source of inaccuracy in the performance of spectral matching. Matrix-matched samples and real samples were screened for proof of applicability. By manual review of data and application of ion ratio and ppm error criteria, false negatives were obtained; this number diminished when in-house library was used, while with on-line MS/MS databases 100% of positive samples were found. In our experience, intensity of peaks across spectra was highly correlated to the concentration effect and matrix complexity. In turn, analysis of spectra acquired at trace concentrations and in different matrices results in better performance in providing correct and reliable identification. Copyright (c) 2014 John Wiley & Sons, Ltd.