Suppression and enhancement of secondary ion formation due to the chemical environment in static-secondary ion mass spectrometry
Suppression and enhancement of secondary ion formation due to the chemical environment in static-secondary ion mass spectrometry
复制标题
DOI：
10.1016/j.jasms.2007.05.014
复制
发表时间：
2007-08-01
影响因子：
3.2
通讯作者：
Vickerman, John C.
中科院分区：
文献类型：
--
作者：
Jones, Emrys A.;Lockyer, Nicholas P.;Vickerman, John C.
通过对已知气相碱性化合物混合物的分析，研究了这一性质对一次离子轰击下表面发射的二次离子的重要性。其目的是为了更好地了解二次离子质谱仪(SIMS)中发生的电离机制。用常用的基质辅助激光解吸电离(MALDI)、基质2，4，6-三羟基苯乙酮(TAP)和一系列低分子生物分子来研究在类似的MALDI实验中观察到的分析物/基质抑制效应是否也存在于静态SIMS中。实验结果表明，混合物中一个分子的准分子信号会因为另一个分子的存在而受到强烈的抑制，化合物的气相碱性是检测到的二次离子的一个很好的指标。还证明了在双组分混合物中加入第三种合适的气相碱度的化合物可以最大限度地减少对化合物准分子离子信号的抑制。
Through analyzing mixtures of compounds of known gas-phase basicities, the importance of this property on the secondary ions emitted from a surface under primary ion bombardment is investigated. The aim is to obtain a greater understanding of the ionization mechanisms that occur in secondary ion mass spectrometry (SIMS). The commonly used matrix assisted laser desorption/ionization (MALDI) matrix 2,4,6-trihydroxyacetophenone (THAP) and a range of low molecular weight biomolecules were used to investigate whether analyte/matrix suppression effects that have been observed in analogous MALDI experiments were also present in static-SIMS. The outcome of the experiments demonstrates that strong suppression of the quasi-molecular signal of one molecule in a mixture can occur due to the presence of the other, with the gas-phase basicity of the compounds being a good indicator of the secondary ions detected. It is also demonstrated that the suppression of the quasi-molecular ion signal of a compound in a two-component mixture can be minimized by the inclusion of a third compound of suitable gas-phase basicity.