Recently, it has been shown that energy‐resolved mass spectrometry (MS) can provide quantitative information from two isomeric or isobaric compounds in mixtures by using the survival yield (SY) technique together with “gas‐phase collisional purification” (GPCP) strategy (Anal. Chem., 2016, 88, p.10821). Herein, we present an improvement and an extension of this concept to the structural analysis of a model mixture of three isobaric compounds (two peptides and a polyether). By using default collision‐induced dissociation (CID) tandem MS parameters on an ion trap instrument, the previous approach did not show any signs of isobaric contamination. However, by modifying CID conditions and using a threefold increase of the He trapping gas pressure (to reach 3.00·10⁻⁵ mbar), the SY curve was unexpectedly and strongly shifted to higher excitation voltages with two plateaus appearing. Those plateaus, indicating clearly the presence of three isobaric compounds, were taken as reliable indicators to perform GPCP at carefully selected excitation voltages in order to selectively fragment one compound after the other. In this way, CID mass spectra of each compound were correctly recovered, both in terms of fragment ion peaks and in terms of relative intensities, from energy‐resolved MSⁿ spectra of the three compounds mixture. This feature enables their unequivocal structural analysis as if samples were free from isobaric interferences. In this paper, we also discuss the possibility for recovering SY curves for pure compounds directly from the mixture. Clearly, in this case, the higher He trapping gas pressure made it possible to use the SY technique, for the first time, for the structural analysis in the case of mixtures of three isobaric compounds. This observation, quite unexpected, demonstrates that the trapping gas pressure is of paramount importance although it is usually not considered in energy‐resolved MS for structural and/or quantitative analysis.

中文翻译：

---

使用高捕集气压的离子阱质谱仪可以通过能量解析质谱法和存活产率技术对混合物中的三种同量异位化合物进行明确的结构分析。

最近，研究表明，通过使用存活率（SY）技术和“气相碰撞纯化”（GPCP）策略，能量分辨质谱（MS）可以提供混合物中两种异构或同量异位化合物的定量信息（分析化学，2016，88，p.10821）。在这里，我们提出了这个概念的改进和扩展，以对三种同量异位化合物（两个肽和一个聚醚）的模型混合物进行结构分析。通过在离子阱仪器上使用默认的碰撞诱导解离（CID）串联MS参数，以前的方法没有显示出任何同量异位污染的迹象。但是，通过修改CID条件并使用三倍的He捕集气体压力（达到3.00·10 ^-5mbar），则SY曲线出乎意料地强烈移至更高的激励电压，并出现两个平台。那些高原，清楚地表明存在三种同量异位化合物，被视为可靠的指标，可以在精心选择的激发电压下进行GPCP，以选择性地将一种化合物依次分解为另一种化合物。通过这种方法，可以从能量分辨的MS ^n中，以碎片离子峰的形式和相对强度的形式正确回收每种化合物的CID质谱图三种化合物混合物的光谱。此功能使它们能够进行明确的结构分析，就好像样品没有等压干扰一样。在本文中，我们还讨论了直接从混合物中回收纯化合物的SY曲线的可能性。显然，在这种情况下，较高的He捕集气体压力使得有可能首次使用SY技术对三种同量异位化合物的混合物进行结构分析。这一观察结果出乎意料，证明了捕集气体的压力至关重要，尽管在能量分辨质谱仪中通常不对其进行结构和/或定量分析。