Desorption/ionization mass spectrometric technique for the analysis of thermally labile compounds based on thermionic emission materials.
Desorption/ionization mass spectrometric technique for the analysis of thermally labile compounds based on thermionic emission materials.
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基于热电子发射材料的解吸/电离质谱技术，用于分析热不稳定化合物。
DOI：
10.1021/ac00130a018
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发表时间：
1987
影响因子：
7.4
通讯作者：
Allison,J
中科院分区：
文献类型：
--
作者：
Bombick,DD;Allison,J
当热不稳定分析物被放置在钾热离子发射器上并加热时，形成代表样品的离子。这已发展成为一种新的电离技术，该技术利用热离子发射器探针，可与任何具有直接插入探针的质谱仪一起使用。讨论了这种电离方法的可能机制。所提出的机制涉及将发射的钾离子气相添加到从表面解吸的中性物质中。这种电离方法称为 K+ IDS（解吸物质的 K+ 电离）。给出了多种化合物的 K+ IDS 光谱示例，包括糖类、药物、肽、类固醇和聚合物。这里还演示了混合物的分析。除了解吸物质的 K+ 电离之外，还可能发生表面电离。表面电离被证明适用于包括黄嘌呤和茶碱在内的一类化合物。热不稳定化合物也可能发生表面电离，产生负离子；此处以肽为例来说明这一点。质谱分析中使用的电离技术的数量不断增长，允许研究多种化合物类型。早期使用电子轰击 (El)、化学电离 (Cl)、场电离 (FI) 和表面电离 (SI) 的质谱分析需要挥发性分析物，这些分析物可以通过气相色谱仪或直接插入探针 (DIP) 引入光谱仪源。热不稳定化合物经常被衍生成挥发性化合物，以便通过这些方法进行分析。
When a thermally labile analyte Is placed on a potassium thermionic emitter and heated, Ions representative of the sample are formed. This has been developed Into a new Ionization technique which utilizes a thermionic emitter probe that can be used with any mass spectrometer having a direct Insertion probe. A possible mechanism for this Ionization method is discussed. The proposed mechanism Involves the gas-phase addition of emitted potassium Ions to neutrals de-sorbed from the surface. This Ionization method Is referred to as K+ IDS (K+ Ionization of desorbed species). Examples of K+ IDS spectra are given for a variety of compounds Including saccharides, pharmaceuticals, peptides, steroids, and polymers. The analysis of mixtures Is alsodemonstrated here. In addition to the K+ Ionization of desorbed species, surface Ionization can occur. Surface Ionization Is demonstrated for the class of compounds that Includes xanthine and theo-phylline. Surface Ionization can also occur for thermally labile compounds, producing negative Ions; this Is shown here by use of a peptide as an example.The number of ionization techniques used in mass spec-trometry is constantly growing, allowing for a wide variety of compound types to be studied. Early mass spectrometric analyses using electronimpact (El), chemical ionization (Cl), field ionization (FI), and surface ionization (SI) required volatile analytes which could be introduced into the spec-trometer source via a gas chromatograph or a direct insertion probe (DIP). Thermally labilecompounds are frequently derivatized into volatile compounds in order to be analyzed by these methods.