Mechanical ion gate for electrospray-ionization ion-mobility spectrometry.

Area of Science:

• Analytical Chemistry
• Spectrometry
• Separation Science

Background:

• Atmospheric pressure ion-mobility spectrometry (IMS) is a powerful analytical technique.
• Effective ion gating is crucial for enhancing IMS performance and resolving complex mixtures.

Purpose of the Study:

• To design, construct, and evaluate a novel ion gate for electrospray-ionization IMS (ESI-IMS).
• To assess the separation capabilities and resolution of the developed ESI-IMS system with the new ion gate.

Main Methods:

• Construction of an ion gate using a chopper wheel with two windows for ion passage and synchronization.
• Assembly of a 45.0 cm drift tube with 78 stainless steel rings and a specific resistor network.
• Application of a -20.0 kV potential to the back plate and grounding the interface plate, maintaining an electric field of ~400 V cm⁻¹.
• Electrospraying of sample solutions at +5.0 kV with +500 V applied to the ion gate.

Main Results:

• The novel ion gate facilitated periodic ion passage from the ESI source into the drift region.
• Baseline separations were achieved for various benzodiazepines, antidepressants, and antibiotics.
• A moderate experimental resolution of approximately 70 was observed.

Conclusions:

• The developed ion gate is effective for ESI-IMS applications.
• The system demonstrates potential for analyzing complex mixtures of pharmaceutical compounds.
• The ion gate design contributes to improved analytical performance in IMS.