Pressure effects in differential mobility spectrometry
Pressure effects in differential mobility spectrometry
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DOI：
10.1021/ac061092z
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发表时间：
2006-11-15
影响因子：
7.4
通讯作者：
Eiceman, Gary A.
中科院分区：
文献类型：
--
作者：
Nazarov, Erkinjon G.;Coy, Stephen L.;Eiceman, Gary A.
在0.4 ~ 1.55大气压范围内工作的微加工平面微分离子迁移谱仪，在净化空气的支持气氛中，研究了压力和电场强度对微分迁移谱中的补偿电压、离子透射率、峰宽和峰强度的影响。发现补偿电压中的峰位作为分离射频电压的函数随压力变化，其变化方式可以通过用E/N的汤森单位表示补偿场和分离场来简化。提供最大补偿电压和最大分辨率的分离电压是离子特异性的，但通常发生在由于电击穿而在高压下无法达到的E/N值处。空气击穿电压在1个大气压附近的压力依赖性是次线性的，允许在降低的压力下达到更高的E/N值，通常导致更高的仪器分辨率。在减压下的较低电压要求也降低了器件功耗。
A microfabricated planar differential ion mobility spectrometer operating from 0.4 to 1.55 atm in a supporting atmosphere of purified air was used to characterize the effects of pressure and electric field strength on compensation voltage, ion transmission, peak width, and peak intensity in differential mobility spectra. Peak positions, in compensation voltage as a function of separating rf voltage, were found to vary with pressure in a way that can be simplified by expressing both compensation and separation fields in Townsend units for E/N. The separation voltage providing the greatest compensation voltage and the greatest resolution is ion-specific but often occurs at E/N values that are unreachable at elevated pressure because of electrical breakdown. The pressure dependence of air breakdown voltage near 1 atm is sublinear, allowing higher E/N values to be reached at reduced pressure, usually resulting in greater instrumental resolution. Lower voltage requirements at reduced pressure also reduce device power consumption.