Parallel Operation of Electron Ionization and Chemical Ionization for GC–MS Using a Single TOF Mass Analyzer
This study describes the first ever use of parallel chemical ionization (CI) and electron ionization (EI) during a single chromatographic separation step with a single time-of-flight (TOF) mass analyzer. The simultaneous generation of molecular ions via chemical ionization next to the fragmentation information of conventionally used EI increases the identification certainties and offers non-targeted analysis approaches using gas chromatography.
The basic principle and performance of the TOFWERK ecTOF is demonstrated and the benefits using both ionizations in parallel is discussed. The performance from the GC-coupling (e.g., peak alignment and timing) downstream towards the ion sources (e.g. fragmentation and sensitivity) and the mass analyzer (e.g. mass accuracy and resolution) is evaluated in detail. In addition, examples for the complementarity of both ionization techniques are shown.