A high sensitivity desorption electrospray ionization mass spectrometry system that employs a heated platform, along with means for directing a liquid stream containing an analyte of interest onto a target location on the heated platform to heat the stream, an electrospray emitter for generating an electrospray and directing the electrospray at the target location on the heated platform to produce an ionized, desorbed analyte, and a mass spectrometer for receiving and detecting the ionized, desorbed analyte.