METHOD AND APPARATUS FOR CONVERSION OF MULTIPLE ANALYTE CATION TYPES TO A SINGLE ANALYTE ANION TYPE VIA ION/ION CHARGE INVERSION

摘要

An apparatus and method for a sample using a mass spectrometer is described, including, generating ions of a first polarity from an analyte using electrospray ionization; generating ions of a second polarity from a reagent; injecting the ions of the first polarity and ions of the second polarity in sequence into a chamber of the mass spectrometer such that the ions of the first polarity and the ions of the second polarity interact in the chamber to form analyte ions having the second polarity; and, analyzing the mass spectrum of the analyte ions of the second polarity. A reagent such as a polyamidomine is selected to preferentially yield analyte ions of the second polarity having a desired mass-to-charge ratio.