您现在的位置: 首页 > 新闻中心 > 行业动态 >  内容

离子液体的高质量簇离子用于正负模式下DART-MS的宽质量范围校正

High-mass High-mass cluster ions of ionic liquids in positive-ion and negative-ion DART-MS and their application for wide-range mass calibrations
使用离子液体的高质量簇离子用于正负模式下DART-MS的宽质量范围校正
 
Jürgen H. Gross
 
Abstract:

Eight ionic liquids (ILs) are subjected to both positive-ion and negative-ion direct analyses in real time (DART) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). First, their ability to deliver evenly distributed cluster ion series covering a wide m/z range is explored. Then, one of the ILs exhibiting particularly useful cluster ion series in either ion polarity is applied for mass calibration. Using 1-butyl-3-methylimidazolium tricyanomethide delivers positive cluster ions suitable for mass calibration in the m/z 100–4,000 range and covers the m/z 100–2,000 range in negative-ion DART-MS. The corresponding mass reference lists are provided for either polarity. Furthermore, based on 1-butyl-3-methylimidazolium tricyanomethide, a high-mass record of m/z>5,000 for positive-ion DART-MS is presented. The mass calibration procedure is finally validated by application to established standard compounds such as polydimethylsiloxanes, perfluorononanoic acid, and Ultramark 1621, a mixture of hexakis (fluoroalkoxy) phosphazenes. Further proof is presented by consistent exact mass differences between adjacent cluster ions.

摘要:

八种离子液体(ILs)被用于与傅里叶变换离子回旋共振(FT-ICR)质谱正负模式下的直接实时分析(DART)。首先研究了它们覆盖宽m/z质量范围并均匀分布系列簇离子的能力,然后发现其中一种离子液体在正负离子模式下均展现出非常有用的簇离子序列可用于质量数校正。采用1-丁基-3-甲基咪唑 三氰甲基盐的簇离子序列适用于DART-MS覆盖正离子m/z 100–4,000、负离子m/z 100–2,000 质量范围的校正,同时提供了正负模式对应的参照质量数列表。并且基于1-丁基-3-甲基咪唑 三氰甲基盐,DART-MS正模式下m/z >5,000 的高质量簇离子也有呈现并被记录。质量校正的过程最终通过应用于已建立标准的化合物,如聚二甲基硅氧烷、全氟壬酸、六(氟烷氧基)磷腈混合物组成的质谱标准物而得到验证,进一步的证明通过邻近的簇离子之间一致的精确质量数差异而被呈现。