A multichannel rotating electrospray ionization mass spectrometry (MRESI): instrumentation and plume interactions
A multichannel rotating electrospray ionization (MRESI) mass spectrometry method is described. It is carried out by rotating three spray emitters infused with the same or different kinds of solvents or solutions. Rotation effect is shown as a critical factor in equalizing the sampling processes from different channels. The interactions of plumes generated from different spray emitters in MRESI has been systematically studied. Due to electrostatic repulsion, liquid fusion of charged droplets from different channels does not occur, while volatile reagents can induce reactions between sprays by vaporizing into neutral gas phase molecules which then extracted by other droplets. When the method is coupled to a laser desorption technique, the desorbed analytes can be post-ionized by multiple electrosprays concurrently, providing a more informative MS detection of a complex sample.