Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
Anal Chem. 2012 Jul 3;84(13):5700-7. doi: 10.1021/ac300887g. Epub 2012 Jun 12.
In our previous work we proposed a three-zone theory for the Bradbury-Nielsen (BN) gate and proved with a grid-BN structure ion mobility drift tube that enhancements of the three-zone features led to higher resolutions and sometimes higher sensitivities. In this work we continued to seek further improvements of the resolution performance by adopting a BN-grid structure in the same drift tube. The postgate grid works both for confinement of the BN gate induced electric field and for isolation of the injection field from the drift field. This makes it possible to obtain better resolutions by further enhancing the compression electric field and lowering the injection field. It was found in the following experiments that reducing the injection field led to higher resolutions yet lower sensitivities. At an injection field of 140 V/cm, the inverse compression coefficient was found to be much larger than that in the grid-BN structure at all gating voltage differences (GVDs). At GVD = 350 V and a gate pulse width of 0.34 ms, the ion mobility spectrometry efficiency R(m)/R(c) reached as high as 221% in the BN-grid structure, presenting a further increase compared to 182% in the grid-BN structure. Finally, two examples are given to show the separation power improvements with good resolutions.
在我们之前的工作中，我们提出了一个用于布拉德伯里-尼尔森（BN）门的三区理论，并通过网格-BN 结构离子迁移率漂移管证明了，三区特征的增强导致了更高的分辨率，有时甚至更高的灵敏度。在这项工作中，我们继续通过在同一漂移管中采用 BN-网格结构来寻求进一步提高分辨率的性能。后栅极网格既用于限制 BN 门感应电场，又用于将注入场与漂移场隔离。这使得通过进一步增强压缩电场和降低注入场来获得更好的分辨率成为可能。在以下实验中发现，降低注入场会导致更高的分辨率和更低的灵敏度。在注入场为 140 V/cm 时，发现逆压缩系数在所有门电压差（GVD）下都远大于网格-BN 结构中的压缩系数。在 GVD = 350 V 和门脉冲宽度为 0.34 ms 时，BN-网格结构中的离子迁移谱效率 R(m)/R(c)高达 221%，与网格-BN 结构中的 182%相比有了进一步的提高。最后，给出了两个例子来说明具有良好分辨率的分离能力的提高。
