Ion-Molecule Reactions

    We study reactions of all sorts of ions, produced by EI (electron ionization), or CI (chemical ionization), with neutral analytes to develop new tools for structural determination of peptides, steroids and other compounds.  The following Figure shows an example of  an ion-molecule reaction used to differentiate isomeric steroids. In this reaction, phosphenium ion reacts differently with the cis and trans steroids (product ions are different), allowing us to differentiate them.