Department of Chemistry, Eastern Kentucky University, Richmond, KY, 40475, USA.
J Am Soc Mass Spectrom. 2013 Oct;24(10):1616-9. doi: 10.1007/s13361-013-0696-8. Epub 2013 Aug 10.
Direct analysis in real time mass spectrometry (DART-MS) was used to analyze ionic liquids (ILs) containing either imidazolium or phosphonium cations combined with different types of inorganic and organic anions. Ionic liquids were directly inserted into the ionization source using a glass probe without dissolution into organic solvents. Mass spectra of the ILs were collected in both positive and negative mode with a linear ion-trap instrument. The intact cation of the compound was typically the dominant peak in positive mass spectra and cluster ion formation was present. Some individual anions were not readily observed in the negative mass spectra (based on the type of anion); however, the mass difference of adjacent cluster ions equal the mass of a complete IL and the anion mass could be verified by subtracting the known cation mass. The degree and intensity of the cluster ion formations was found to be dependent on the nature of the specific ILs as well as the DART temperature gas stream.
直接实时分析质谱法 (DART-MS) 用于分析含有咪唑鎓或鏻阳离子的离子液体 (IL)，这些阳离子与不同类型的无机和有机阴离子结合。离子液体直接用玻璃探头插入离子源，无需溶解在有机溶剂中。使用线性离子阱仪器在正、负模式下收集 IL 的质谱。在正质谱中，化合物的完整阳离子通常是主要峰，存在簇离子形成。在负离子谱中，有些阴离子不易观察到（基于阴离子的类型）；然而，相邻簇离子的质量差等于完整 IL 的质量，并且可以通过减去已知阳离子的质量来验证阴离子的质量。发现簇离子形成的程度和强度取决于特定 IL 的性质以及 DART 温度气流。
