| Autor: |
PNNL Omics, Hamid, Ahmed M., Sandilya V.B. Garimella, Ibrahim, Yehia, Liulin Deng, Prabhakaran, Aneesh, Webb, Ian K, Gordon A, Anderson, Prost, Spencer A., Norheim, Randolph V., Sandoval, Jeremy A., Schilmelfenig, Colby E., Baker, Erin S., Smith, Richard D. |
| Rok vydání: |
2017 |
| DOI: |
10.6084/m9.figshare.5146084.v1 |
| Popis: |
The applicability and benefits of Ion mobility (IM) techniques increase with their separation power, which can be enhanced by increasing the applied field or ion path length. Here, we present a new compact multilevel Structures for Lossless Ion Manipulations (SLIM) module that is capable of achieving very high resolution by using extremely long ion path for traveling wave ion mobility (TWIM) separations. This presentation will describe the novel approaches of using “escalators” and “elevators” to guide ions across multiple SLIM levels with no loss to the achieved sensitivity and resolution. Moreover, the ability to efficiently move ions between different levels of multilevel SLIM devices will greatly expand the range of potential applications and enable more complex ion manipulations. SLIM long serpentine path length multilevel modules have been developed which use the new TW escalators or TW elevators to transport ion packets between SLIM levels. SLIM relies on three arrays of electrodes to which RF, TW and guard potentials are applied to confine and manipulate ions. The arrays of electrodes are deposited on two planar nonconductive surfaces utilizing printed-circuit board technology. To create a compact design, the electrodes are patterned on both sides of the SLIM surfaces, enabling the eventual extension of the ion path length to ~1 km hosted in a 17”x17”x10” chamber. The SLIM devices have been evaluated at a pressure of ~4 torr N2. We have previously demonstrated SLIM TW ion mobility separation modules with short as well as long serpentine paths by moving ions in a single plane. However, in order to expand the use of these high resolution, highly flexible SLIM devices for a range of applications, they would benefit from being more compact. Therefore, efficient use of the available space is crucial. Therefore, expanding the ion path into three dimensions is expected to lead to much higher resolution without increasing the footprint of the TWIM instrument. In this work we evaluated an ion escalator in a short SLIM module (~31 cm). Ion current measurements confirmed the lossless nature of the ion transmission. We also show that the TWIM resolution was conserved in the TW escalator, allowing the separation of ions with very similar structural features. The ion mobility resolution was optimized by adjusting the TW speed, amplitude, RF amplitude, guard bias and the gap between the SLIM surfaces. Moreover, in order to increase the TWIM resolution using the same instrumentation profile, we investigated a new “TW elevator” approach using theoretical and experimental approaches. Ion trajectory simulations using TW were performed using SIMION 8.1 on an elevator module and which showed that the efficient operation of an elevator based TW-SLIM device is feasible in the context of a double-sided surface design that has one TW electrode at the edge of the orifice to transfer ions between two SLIM levels. In addition, negligible ion loss was indicated from the ion trajectory simulations for the elevators. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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