Steiner Wes E, English William A, Hill Herbert H
SAIC/Geo-Centers, Edgewood Chemical Biological Center Operations, Aberdeen Proving Grounds, Maryland USA.
J Phys Chem A. 2006 Feb 9;110(5):1836-44. doi: 10.1021/jp056158t.
The ion mobilities and their respective masses of several classes of amines (primary, secondary, and tertiary) were measured by electrospray ionization atmospheric pressure ion mobility time-of-flight mass spectrometry IM(tof)MS. The experimental data obtained were comparatively analyzed by the one-temperature kinetic theory of Chapman-Enskog. Several theoretical models were used to estimate the collision cross-sections; they include the rigid-sphere, polarization-limit, 12-6-4, and 12-4 potential models. These models were investigated to represent the interaction potentials contained within the collision integral that occurs between the polyatomic ions and the neutral drift gas molecules. The effectiveness of these collision cross-section models on predicting the mobility of these amine ions was explored. Moreover, the effects of drift gas selectivity on the reduced-mass term and in the collision cross-section term was examined. Use of a series of drift gases, namely, helium, neon, argon, nitrogen, and carbon dioxide, made it possible to distinguish between mass effects and polarizability effects. It was found that the modified 12-4 potential that compensates for the center of charge not being at the same location as the centers of mass showed improved agreement over the other collision cross-section models with respect to experimental data.
通过电喷雾电离大气压离子迁移时间飞行质谱法（IM（tof）MS）测量了几类胺（伯胺、仲胺和叔胺）的离子迁移率及其各自的质量。利用查普曼 - 恩斯科格单温度动力学理论对获得的实验数据进行了比较分析。使用了几种理论模型来估计碰撞截面；它们包括刚性球体、极化极限、12 - 6 - 4和12 - 4势模型。研究这些模型以表示多原子离子与中性漂移气体分子之间碰撞积分中包含的相互作用势。探讨了这些碰撞截面模型在预测这些胺离子迁移率方面的有效性。此外，还研究了漂移气体选择性对折合质量项和碰撞截面项的影响。使用一系列漂移气体，即氦气、氖气、氩气、氮气和二氧化碳，使得区分质量效应和极化率效应成为可能。结果发现，针对电荷中心与质心位置不同而修正的12 - 4势，与其他碰撞截面模型相比，在实验数据方面显示出更好的一致性。
