Realization of In-Source Collision-Induced Dissociation in Single-Photon Ionization Time-of-Flight Mass Spectrometry and Its Application for Differentiation of Isobaric Compounds
Realization of In-Source Collision-Induced Dissociation in Single-Photon Ionization Time-of-Flight Mass Spectrometry and Its Application for Differentiation of Isobaric Compounds
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单光子电离飞行时间质谱中源内碰撞诱导解离的实现及其在同量异位化合物区分中的应用
DOI：
10.1021/ac5043768
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发表时间：
2015
影响因子：
7.4
通讯作者：
Li Haiyang
中科院分区：
文献类型：
--
作者：
Hua Lei;Hou Keyong;Chen Ping;Xie Yuanyuan;Jiang Jichun;Wang Yan;Wang Weiguo;Li Haiyang
单光子电离质谱（SPI-MS）是一种多功能的、强大的在线和实时分析有机物种的分析技术;然而，它面临着缺乏所研究分子的结构信息的固有缺点，更不用说区分同量异位化合物了。在这项工作中，我们描述了将源内碰撞诱导解离（CID）集成到SPI-MS仪器中的SPI离子源的首次尝试。通过将离子源中的压力升高到中等真空压力（MVP）并提高提取电压来实现源内CID。借助于源内CID，可以获得SPI诱导的分子离子和CID产生的碎片离子质谱，以赋予每种分析物其独特的光谱“指纹”。通过分析分子量分别为72和106 Da的两组同量异位化合物，以及对二甲苯和二甲苯混合气体的定量分析，证明了该方法区分同量异位化合物的能力。因此，具有不同特征碎片离子或外观能量的同量异位素化合物可以成功地区分。本工作为SPI-MS的实际应用提供了一种不需要MS/MS技术或耦合额外分离技术就能方便、快速地鉴别同量异位素化合物的可行方法。
Single-photon ionization mass spectrometry (SPI-MS) is a versatile and powerful analytical technique for online and real-time analysis of organic species; however, it is confronted with an intrinsic drawback of lacking structural information on the investigated molecules, let alone differentiation of isobaric compounds. In this work, we describe a first attempt to integrate in-source collision-induced dissociation (CID) to the SPI ion source in a SPI-MS instrument. The in-source CID was accomplished by elevating the pressure in the ion source to medium vacuum pressure (MVP) and raising the extraction voltage. With the aid of in-source CID, both the SPI-induced molecular ion and CID-generated fragment ion mass spectra can be obtained to endue each analyte with its unique spectrometric “fingerprint”. The capability for differentiation of isobaric compounds is demonstrated by analyzing two groups of isobaric compounds with molecular weights of 72 and 106 Da, respectively, and quantitative analysis ofp-xylene and ethylbenzene in gas mixture. As a result, isobaric compounds with different characteristic fragment ions or appearance energies can be successfully distinguished. The work presents a feasible method for practical applications of SPI-MS to differentiate isobaric compounds conveniently and rapidly without MS/MS technique or coupling additional separation technologies.