Novel ion drift tube for high-performance ion mobility spectrometers based on a composite material

Abstract

Ion mobility spectrometers (IMS) are able to detect pptV-level concentrations of substances in gasses and in liquids within seconds. Due to the continuous increase in analytical performance and reduction of the instrument size, IMS are established nowadays in a variety of analytical field applications. In order to reduce the manufacturing effort and further enhance their widespread use, we have developed a simple manufacturing process for drift tubes based on a composite material. This composite material consists of alternating layers of metal sheets and insulator material, which are connected to each other in a mechanically stable and gastight manner. Furthermore, this approach allows the production of ion drift tubes in just a few steps from a single piece of material, thus reducing the manufacturing costs and efforts. Here, a drift tube ion mobility spectrometer based on such a composite material is presented. Although its outer dimensions are just 15 mm × 15 mm in cross section and 57 mm in length, it has high resolving power of Rp = 62 and detection limits in the pptV-range, demonstrated for ethanol and 1,2,3-trichloropropane.

Perspective Chapter: Advantages of Ion Mobility Coupled with HPLC/UPLC

“…Drift tube ion mobility spectrometry (DTIMS) is potentially the simplest of the ion mobility techniques based on a simplified structural and parameter interplay [2,4]. The drift tube is filled with a defined volume of buffer gas with no directional flow, which acts as a velocity regulator to moving ions [4].…”

“…Drift tube ion mobility spectrometry (DTIMS) is potentially the simplest of the ion mobility techniques based on a simplified structural and parameter interplay [2,4]. The drift tube is filled with a defined volume of buffer gas with no directional flow, which acts as a velocity regulator to moving ions [4]. The ions are propelled through the drift tube by a uniformly applied, static electric field with a decreasing voltage as the ions traverse the drift tube [2,4].…”

“…The drift tube is filled with a defined volume of buffer gas with no directional flow, which acts as a velocity regulator to moving ions [4]. The ions are propelled through the drift tube by a uniformly applied, static electric field with a decreasing voltage as the ions traverse the drift tube [2,4]. As seen in Figure 1, the drift tube is made up of stacked electrodes that allow for the electric field to be applied over the length of the tube.…”

“…As seen in Figure 1, the drift tube is made up of stacked electrodes that allow for the electric field to be applied over the length of the tube. The static electric field, defined drift tube length, and time it takes to traverse the entire length of the drift tube allow for ionic separation and CCS calculations [4]. One of the disadvantages of the DTIMS system is the voltage drop across the length of the tube.…”

Towards a hand-held, fast, and sensitive gas chromatograph-ion mobility spectrometer for detecting volatile compounds

“…Consequently, system miniaturization is necessary. Different approaches for miniaturized IMS drift tubes have been presented, still showing fast response times and low detection limits [13][14][15][16][17]. However, gas mixtures always pose a challenge for IMS not only due to the limited resolving power but moreover due to chemical cross sensitivities associated with atmospheric pressure chemical ionization (APCI).…”