Development of Differential Ion Mobility Spectrometry Based Tandem Devices for Ion Separation Prior to Mass Spectrometry Analysis

Rationale

Differential ion mobility spectrometry (DMS) provides distinct potential in separation of gas phase ions. However, the resolving power still limits the widespread application of DMS technology and inspires to design tandem DMS for improvement of the performance.

Methods

A robust tandem DMS module was fabricated to enhance the separation performance of the DMS system. To achieve the optimal separation, two carrier gas composition modulation strategies were carried out by adding different types of organic modifiers and by changing the modifier concentration in each DMS channel. The working performance of the home-made CaptiveSpray-tandem DMS-MS was evaluated by investigating the peak intensity and FWHM using reserpine and comparing the peak positions of peptide mixtures in two DMS channels.

Results

When carrier gas composition in two channels was controlled appropriately, the tandem DMS system could provide the DMS system with another dimension for ion separation and therefore enhance the separation ability. Two gas modification methods could be applied in this system for enhancing analytical performance.

Conclusions

This tandem DMS platform allows precise control of the gap widths of the DMS channels and enables the modulation of carrier gas composition in two DMS channels separately. The developed method is capable of providing orthogonal separation behavior and achieving higher separation performance.