A modified version of desorption electrospray ionization mass spectrometry was developed for (i) better utilization of analyte ions and (ii) larger sampling area via synchronization the pulsed nebulizer gas with ion injection. To synchronize the sheath gas, gas flow was paused for 50 ms within each cycle, leading to solvent accumulation at the end of emitter tip. That solvent accumulation enlarged the desorption areas. As a result, the amount of analytes increased. Thus, the improved signal intensity (~ 2-5-folds for various substrates) was benefit from both better analyte ion utilization and larger desorption areas. Finally, the enhanced signal intensity was confirmed with both garlic homogenate and brain homogenate. Graphical Abstract ᅟ.
Keywords: Ion generation; Ion injection; Mass spectrometer; Signal enhancement; Synchronized desorption electrospray ionization.