Liu Qiang, He Lin
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
J Am Soc Mass Spectrom. 2008 Jan;19(1):8-13. doi: 10.1016/j.jasms.2007.10.002. Epub 2007 Oct 9.
Deuterated solvents and DIOS surfaces derivatized with different functional groups are used to investigate impacts of local chemical environment on analyte ionization. Both solvent molecules and surface functional groups are found to directly participate in analyte protonation in the condensed phase. The corresponding protonation effectiveness is quantitatively estimated based on the relative MS peak intensities of [M+2]+/[M+1]+. A direct correlation between ionization of triethylamine and the relative acidities of the surface and the solvent is evident. In addition, the proton donating effectiveness of a solvent is found to be related to its vapor pressure. Improved MS detection of small molecules via proper surface treatment and solvent selection is demonstrated.
使用氘代溶剂和用不同官能团衍生化的DIOS表面来研究局部化学环境对分析物电离的影响。发现溶剂分子和表面官能团都直接参与凝聚相中分析物的质子化。基于[M + 2]+/[M + 1]+的相对质谱峰强度定量估计相应的质子化效率。三乙胺的电离与表面和溶剂的相对酸度之间存在明显的相关性。此外,发现溶剂的质子给予效率与其蒸气压有关。通过适当的表面处理和溶剂选择,小分子的质谱检测得到了改善。