Abstract:
Ion mobility spectrometry (IMS) is a trace detection technique. It realizes rapid separation and detection of ions by capitalizing on the disparities in the mobility velocities of ions in an electric field under atmospheric pressure. The ion gate is one of the core components for controlling the detection of IMS signals. Driving and controlling the ion gate effectively by means of the ion gate power supply is one of the main approaches to enhance the detection performance of IMS. The technology of inverse ion mobility spectrometry (IIMS) reverses the control mode of the ion gate in traditional IMS from “off-on-off” to “on-off-on”. As the ion gate remains open for an extended period, the drift region of the drift tube is filled with a continuous ion flow. When the ion gate is briefly closed, a charge-free depression peak emerges in the continuous ion flow. Due to the strong Coulomb repulsion among ions, the depression peak is narrowed, and the resolution of IIMS is increased by 30% to 60% compared to traditional IMS. Nonetheless, the ion gate drive power supply required for IIMS necessitates the incorporation of a high-voltage isolation circuit, which complicates the system architecture and increases associated costs. This research carried out a study on the power supply control technology for the IIMS ion gate. The proposed power supply was characterized by its simplified architecture, the elimination of additional high-voltage isolation circuits, reduced manufacturing costs, and improved ease of control. Testing results indicated that the pulse rise and fall response times of this power supply conform to the established design specifications and adequately fulfill the signal detection requirements of IIMS. Experimental validation utilizing the reactant ions of IIMS revealed that the effects of pulse amplitude and pulse width on IIMS performance align with theoretical predictions. Moreover, the resolution of IIMS improved by 45% in comparison to traditional IMS, thereby corroborating reported literature and reinforcing the feasibility of this ion gate drive power supply for IIMS applications.