Electron Microscopy, NMR & Mass Spectometry News

JEOL (Europe) BV introduces: Photo Ion-Source for JMS-T200GC AccuTOF GCx

Electron ionization (EI), generally used for GC/MS and GCxGC/MS analysis, produces fragment ions. Fragments are valuable for database search and compound identification. However, fragmentation adds an additional level of complexity in interpreting complex mixtures, such as crude oil. Some compounds (e.g. alkanes, alcohols) do not produce abundant (or any) molecular ions.

Since photoionization (PI) is a softer ionization method than EI, molecular ion can be easily distinguished using this technique. For some analytes, characteristic fragment ions may also be observed. Combining soft ionization with high-resolution exact-mass data and new software tools simplifies processing of complex GC and GCxGC data (e.g. petroleum type analysis).

PI provides clear molecular ions and elemental composition that can be combined with EI data to identify unknowns and also provides selective ionization of target compounds

The JEOL PI source is designed as a PI/EI combination ion source. Switching between PI and EI can be done without breaking vacuum of the ion source, even without breaking any vacuum. Also during an analytical run it is possible to switch between PI/EI and vice versa. The accurate mass will always stay available whatever ionisation technique is used with our JMS-T200GC AccuTOF GCx.

At this moment a PI source is available for our GC-TOF and GC-Quadrupole systems.