Indium-alkene complex ions as reagents for selective chemical ionization.

Abstract

A major analytical goal of chemical ionization (CI) mass spectrometric analysis of mixtures is to selectively ionize components while minimizing fragmentation and chemical interferences. For such analyses to be feasible, suitably specific chemical ionization reagents are necessary and should provide both unambiguous molecular weight information and the capability for quantitative target compound analysis. Selective chemical ionization also can serve as the first step in tandem mass spectrometric analyses (MS/MS) of mixtures where structure elucidation is the goal. Although there has been a good deal of progress in development of selective reagents for chemical ionization, their applications to direct mixture analysis are still relatively unexplored. Use of metals or metal complex ions as CI reagents is emerging as an area of active current research interest. The authors recently suggested that indium-alkene complex ions might be promising as reagents for selective chemical ionization mass spectrometry. Here, they demonstrate the potential of this method by applying it to analysis of a model mixture and to an unleaded gasoline sample using InC/sub 3/H/sub 6//sup +/ generated via laser desorption Fourier transform mass spectrometry (LD-FTMS) as a chemical ionization reagent.