CYCLIC KETONE MIXTURE ANALYSIS USING 2+1 RESONANCE-ENHANCED MULTIPHOTON IONIZATION MASS-SPECTROMETRY

2 + 1 resonance-enhanced multiphoton ionization (REMPI) has been used for qualitative and quantitative analysis of cyclic ketone mixtures. A multidimensional analysis technique has been employed to eliminate the need to separate mixture components prior to analysis by time of flight mass spectrometry (TOF/MS). The separation step is unnecessary when the analyte is introduced into the mass spectrometer in a molecular beam. The high degree of ro-vibrational cooling of the analyte in the molecular beam reduces spectral congestion, which permits selective ionization of each mixture component. A new approach to this multidimensional technique permits the analysis of mixtures containing geometric and stereoisomers. Our method utilizes the electron signal as the means for detecting ions and employs a hard ionization scheme. In addition, accurate and precise quantitation with 2 + 1 REMPI is demonstrated for nanomoles of analyte.