Evaluation of ultrahigh resolution ion mobility spectrometry as an analytical separation device in chromatographic terms
✍ Scribed by G. Reid Asbury; Herbert H. Hill Jr.
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 138 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1040-7685
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✦ Synopsis
An ion mobility spectrometer IMS that routinely achieves separation efficiencies in line with the theoretical diffusion limited maximum has been constructed. The theoretical maximum efficiency is a function of the total voltage drop, the temperature, the number of charges on the ion, the initial pulse width, Ž . the length of the spectrometer, and the mobility K of the ion of interest. Despite the fact that our current instrumental setup uses modest voltages and fairly high temperatures, we were able to achieve over 130,000 theoretical plates for a singly charged ion in less than 25 ms. In addition, selectivity can be altered in IMS by Ž . changing the drift gas or by increasing the electric field )1000 Vrcm such that the mobility of ions is no longer a linear function of the electric field. Separation Ž . factors ␣ can be altered by as much as 20% by changing the drift gas in the spectrometer. Finally leucine and isoleucine were separated in less than 23 ms with a resolution of 0.668 demonstrating the separation power of the instrument.