Effects of drift-gas polarizability on glycine peptides in ion mobility spectrometry
Effects of drift-gas polarizability on glycine peptides in ion mobility spectrometry
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DOI：
10.1016/s1387-3806(02)00626-7
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发表时间：
2002-05-15
影响因子：
1.8
通讯作者：
Hill, HH
中科院分区：
文献类型：
--
作者：
Beegle, LW;Kanik, I;Hill, HH
本研究是我们之前关于利用超高分辨率电喷雾电离/离子迁移谱法（ESI/IMS）原位分析生物分子化合物可行性研究的延续。我们研究的化合物是最小的氨基酸甘氨酸和它的四种低聚物，即甘油三酯、四甘氨酸、五甘氨酸和六甘氨酸。利用四种具有不同极化率值的漂移气体（He、Ar、N-2和CO2），探讨了漂移气体极化率对IMS中目标离子的实验影响。采用简单的硬球模型，通过还原离子迁移率、K-0(m)和有效漂移气体半径计算了所有五种化合物的气相离子半径。当离子半径与漂移气体的极化率相对应时，得到了不同斜率的线性曲线。这一经验观察表明，漂移气体的极化可以在有限的极化值范围内以线性方式改变计算的离子半径，并不是对所有离子都有相同的影响。可以利用这种效应来改变不同离子之间的分离因子，因为理论上，所有产生不同斜率的离子都可以使用不同的漂移气体与IMS分离。我们证明了分离因子（alpha）高度依赖于漂移气体。当使用He和CO2时，实现了最大的可分离性，从而实现了对目标离子的唯一识别。(C) 2002年Elsevier Science B.V.出版
This investigation is a continuation of our previous work on the feasibility of utilizing ultra-high resolution electrospray ionization/ion mobility spectrometry (ESI/IMS) for in situ analysis of biomolecular compounds. The compounds we studied, in this investigation, were glycine, the smallest amino acid and four of its oligomers, namely triglycine, tetraglycine, pentaglycine, and hexaglycine. Experimental effects of drift-gas polarizability on target ions in IMS were explored by utilizing four different drift-gases with differing polarizability values (He, Ar, N-2, and CO2). The gas-phase ion radii for all five compounds were calculated from the reduced ion mobilities, K-0(m), and the effective drift-gas radii employing a simple hard-sphere model. When ion radii were plotted against the polarizabilities of the drift-gases, linear plots with different slopes were produced. This empirical observation indicated that the polarizing of drift-gas can change the calculated ion radii in a linear fashion over a limited range of polarizability values and does not affect all ions equally. This effect can be exploited in order to alter the separation factors between different ions since all ions that yield different slopes can, theoretically, be separated with IMS using different drift-gases. We demonstrated that the separation factor (alpha) is highly dependent on the drift-gas. The maximum separability and, hence, unique identification of target ions was achieved when He and CO2 were used. (C) 2002 Published by Elsevier Science B.V.