Carbon disulfide as a dopant in photon-induced chemical ionization mass spectrometry.
Carbon disulfide as a dopant in photon-induced chemical ionization mass spectrometry.
复制标题
二硫化碳作为光子诱导化学电离质谱中的掺杂剂。
DOI：
10.1002/rcm.6644
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
T. Benter
中科院分区：
文献类型：
--
作者：
Faezeh Dousty;R. T. O'brien;R. Gahler;H. Kersten;T. Benter
理由
已显示向质谱仪的大气压光电离（APPI）源添加掺杂剂可增强分析物电离的程度。一系列不同的掺杂剂已被成功地利用;然而，很少有关于好的掺杂剂的特性的出版物。我们提出了二硫化碳（CS2）作为一种新型的新掺杂剂的基础上，其吸收截面的真空紫外光子的能量和其独特的气相离子化学，特别是事实上，它不包含质子。
方法
CS2增强APPI电离效率的能力通过使用一组具有不同质子亲合势（PA）和电子亲合势（EA）的化合物来测试。将这些结果与使用常用掺杂剂甲苯和苯甲醚获得的结果进行比较。特别注意相对于[M+H]（+）离子的[M]（+）离子的形成。使用配备有商业Photomate™光电离源的沃茨Quattro Premier液相色谱/串联质谱（LC/MS/MS）系统收集质谱。
结果
结果表明，CS2提高了大多数分析物的电离效率，在这项工作中研究的甲苯和苯甲醚。CS2促进[M]（+）和[M+H]（+）的两种电离途径。此外，由于CS2（10.01）的电离能（IE）高于甲苯（8.83）和苯甲醚（8.20）的IE，CS2可以提高分析物的电离效率，而甲苯和苯甲醚不能提高分析物的电离效率。
结论
我们已经确定CS2是用于APPI源的可行掺杂剂。对于某些分析物，观察到显著的[M+H]（+）离子信号;因此，所提供的质子必须来自水簇或溶剂。此外，CS2比甲苯和苯甲醚促进具有低PA和高IE的分析物的电离。
RATIONALE
The addition of a dopant to an Atmospheric Pressure PhotoIonization (APPI) source of a mass spectrometer has been shown to enhance the degree of analyte ionization. A series of different dopants has been successfully utilized; however, there has been very little published on the characteristics of a good dopant. We have proposed carbon disulfide (CS2) as a novel new dopant based on its absorption cross-section for the VUV photon's energy used and its unique gas-phase ion chemistry, notably the fact that it does not contain a proton.
METHODS
The ability of CS2 to enhance the ionization effectiveness of APPI was tested by using a group of compounds that have different proton affinities (PAs) and electron affinities (EAs). These results were compared to results obtained using the commonly used dopants, toluene and anisole. Particular attention was paid to the formation of [M](+) ions relative to [M+H](+) ions. Mass spectra were collected using a Waters Quattro Premier liquid chromatography/tandem mass spectrometry (LC/MS/MS) system equipped with a commercial Photomate™ photoionization source.
RESULTS
The results show that CS2 increases the ionization efficiency of most of the analytes studied in this work comparably to toluene and anisole. CS2 promotes both ionization routes of [M](+) and [M+H](+). In addition, due to the higher ionization energy (IE) of CS2 (10.01) compared to the IEs of toluene (8.83) and anisole (8.20), CS2 can enhance the ionization efficiency of analytes that cannot be enhanced with toluene and anisole.
CONCLUSIONS
We have determined that CS2 is a viable dopant for use in APPI sources. For some analytes, significant [M+H](+) ion signals are observed; therefore, the donated proton must come from either water clusters or solvents. In addition, CS2 promotes the ionization of analytes with low PAs and higher IEs than that of toluene and anisole.