DUAL TIME-OF-FLIGHT MASS SPECTROMETER--HIGH SPEED MS/MS

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The goal of the proposed research is to continue the development of a tandem mass spectrometry (MS/MS) instrument capable of greatly increasing the amount of MS/MS data obtainable from sample components as they are eluting from a chromatographic column. The inability of current MS/MS instrumentation to collect more than a few mass scans during the elution time of a single component has made the great characterizing power of MS/MS analysis unavailable for components requiring prior chromatographic separation. The proposed instrument will have a significant applicability in pharmaceutical analysis and other bioresearch applications where it will offer unique and complementary capabilities to the quadupole and sector MS/MS instruments widely used in modern biomedical laboratories. The achievement of greatly increased MS/MS data rate without a reduction in sensitivity requires the abandonment of tandem mass filters in favor of a mass array analyzer. The instrument under development uses continuous ionization with ion storage for maximum utilization of continuous feed sample, pulsed ion extraction with an ion mirror for high resolution ion bunching at an interaction region, fragmentation of precursor ions of selected m/z value by photodissociation or surface- induced dissociation at the interaction region, time-of-flight analysis of the product ions, and time-array detection to produce a complete product ion spectrum for each ion extraction pulse. Over 500 such spectra can be produced each second with unit mass resolution for both precursor ion selection and product ion detection. The functioning instrument will be used to explore relevant applications in gas chromatography MS/MS analysis and continued new instrumentation developments in liquid chromatography MS/MS and MALDI/MS/MS. In addition, the proposed fundamental studies of the PID process on molecules of structural and biological interest will have significant implication regarding the potential application of PID in a wide variety of MS/MS instrumentation.