Comparison of Solvent Delivery for Enhancing Desportion Electrospray Ionization (DESI) Sources

Abstract

The DESI source for mass spectrometry is becoming increasingly important for applications such as biological tissue imaging and drug detection methods for forensic applications. It functions by desorbing ions from a surface via created electrospray solvent drops. Source functioning can be limited by the coupled solvent delivery system creating the droplets. In this work, two solvent delivery systems were studied to determine which provided more consistent droplet creation for increasing the stability of the response and ultimately enhancing the quality of DESI technique. Research was performed on a DESI-2D platform coupled with an amaZon speed ion trap mass spectrometer. The solvent delivery systems compared were the Fusion 100 infusion (syringe) pump and a milliGAT pump. Pump performance was determined by analyzing the ion response of the model compound rhodamine 6G. Stability was defined as minimized fluctuation in ion response. The milliGAT pump reflected minimized fluctuation due to the continuous flow its mechanics provides. Accurate statistical analysis must be conducted to further define the ion current vs. time plots obtained. Future work will explore the milliGAT pump for efficient low-limit detection and imaging applications for enhancing DESI capabilities.