In‐source collision‐induced dissociation (CID) is commonly used with single‐stage high‐resolution mass spectrometers to gather both a molecular formula and structural information through the collisional activation of analytes with residual background gas in the source region of the mass spectrometer. However, unlike tandem mass spectrometry, in‐source CID does not involve an isolation step prior to collisional activation leading to a product ion spectrum composed of fragment ions from any analyte present during the activation event. This work provides the first comparison of in‐source CID and beam‐type CID spectra of emerging synthetic drugs on the same instrument to understand the fragmentation differences between the two techniques and to contribute to the scientific foundations of in‐source CID. Electrospray ionization–quadrupole time‐of‐flight (ESI‐Q‐TOF) mass spectrometry was used to generate product ion spectra from in‐source CID and beam‐type CID for a series of well‐characterized fentanyl analogs and synthetic cathinones. A comparison between the fragmentation patterns and relative ion abundances for each technique was performed over a range of fragmentor offset voltages for in‐source CID and a range of collision energies for beam‐type CID. The results indicate that large fragmentor potentials for in‐source CID tend to favor higher energy fragmentation pathways that result in both kinetically favored pathways and consecutive neutral losses, both of which produce more abundant lower mass product ions relative to beam‐type CID. Although conditions can be found in which in‐source CID and beam‐type CID provide similar overall spectra, the in‐source CID spectra tend to contain elevated noise and additional chemical background peaks relative to beam‐type CID.

中文翻译：

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使用高分辨率四极杆飞行时间质谱仪比较新兴合成药物的源内碰撞诱导解离和束型碰撞诱导解离

源内碰撞诱导解离（CID）通常与单级高分辨率质谱仪一起使用，以通过质谱仪源区域中残留气体与分析物的碰撞活化来收集分子式和结构信息。但是，与串联质谱法不同的是，源内CID在碰撞活化之前不涉及隔离步骤，从而导致产物离子光谱由活化过程中存在的任何分析物的碎片离子组成。这项工作提供了在同一台仪器上新兴合成药物的源CID和束型CID光谱的首次比较，以了解两种技术之间的碎片差异，并为源CID的科学基础做出了贡献。电喷雾电离-四极杆飞行时间（ESI-Q-TOF）质谱用于从源CID和束型CID生成一系列特征明确的芬太尼类似物和合成卡西酮的产物离子谱。在源内CID的一系列碎裂剂或偏移电压和束型CID的一系列碰撞能量的范围内，对每种技术的碎裂模式和相对离子丰度进行了比较。结果表明，源内CID的较大碎裂势可能倾向于较高的能量碎裂途径，从而导致动力学上有利的途径和连续的中性损失，相对于束流型CID，这两种途径均产生更丰富的较低质量的产物离子。尽管可以找到源CID和波束类型CID提供相似的整体光谱的条件，