Effects of Drift Gas Selection on the Ambient-Temperature, Ion Mobility Mass Spectrometry Analysis of Amino Acids
Effects of Drift Gas Selection on the Ambient-Temperature, Ion Mobility Mass Spectrometry Analysis of Amino Acids
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DOI：
10.1021/acs.analchem.6b04605
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发表时间：
2017-02-07
影响因子：
7.4
通讯作者：
Bush, Matthew F.
中科院分区：
文献类型：
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作者：
Davidson, Kimberly L.;Bush, Matthew F.
离子迁移率(IM)根据离子在漂移气体存在时对电场的响应来分离离子。由于其快速和灵敏的特点，IM和MS的结合为小分子的分析提供了许多潜在的优势。为了确定漂移气体的选择对IM分离信息量的影响，在射频限制漂移池中进行了低压常温离子迁移率实验，测量了20种常见氨基酸与He、N-2、Ar、CO2和N(2)0的绝对碰撞截面(Omega)。漂移气体的选择跨越了质量、几何形状和极化率的范围。使用其峰容量来量化每个分离的信息量，这取决于影响峰宽的因素以及分析物的欧米伽相对于平均欧米伽的范围。通过计算每个氨基酸离子成对组合的峰-峰分辨率来量化每个分离的选择性。被分解的对的数量强烈地依赖于峰容量，但被分解的对的身份也取决于漂移气体。因此，使用不同漂移气体的结果是部分正交的，并提供了互补的化学信息。这些实验使用的温度和压力与许多IM-MS仪器中使用的温度和压力相似，因此，本研究结果适用于优化当前和未来广泛的IM-MS实验的信息内容。
Ion mobility (IM) separates ions based on their response to an electric field in the presence of a drift gas. Because of its speed and sensitivity, the integration of IM and mass spectrometry (MS) offers many potential advantages for the analysis of small molecules. To determine the effects that drift gas selection has on the information content of IM separations, absolute collision cross sections (Omega) with He, N-2, Ar, CO2, and N(2)0 were measured for the 20 common amino acids using low-pressure, ambient-temperature ion mobility experiments performed in a radio frequency-confining drift cell. The drift gases were selected to span a range of masses, geometries, and polarizabilities. The information content of each separation was quantified using its peak capacity, which depended on factors contributing to widths of peaks as well as the range of Omega relative to the average Omega for the analytes. The selectivity of each separation was quantified by calculating the peak-to-peak resolution for each pairwise combination of amino acid ions. The number of pairs that were resolved depended strongly on the peak capacity, but the identities of the pairs resolved also depended on the drift gas. Therefore, results using different drift gases are partially orthogonal and provide complementary chemical information. The temperatures and pressures used for these experiments are similar to those used in many IM-MS instruments, therefore, the outcomes of this research are applicable to optimizing the information content of a wide range of contemporary and future IM-MS experiments.