Select-eV
Award-winning soft electron ionisation technology for GC–MSHarness the power of Tandem Ionisation®…
Markes’ patented Select-eV® technology allows you to switch easily between hard and soft ionisation to generate complementary information about each component, increasing the dimensionality of your analysis.
Tandem Ionisation now adds unparalleled capabilities to GC–MS analyses. Soft and hard ionisation spectra are obtained simultaneously across a single run, for both GC and GC×GC analyses, allowing comprehensive characterisation of complex samples and easing the speciation of isomers.
All the benefits of soft ionisation without the hassle
- - Tandem Ionisation® for full sample characterisation in a single run.
- - Variable-energy ionisation (from 10–70 eV).
- - No source-switching or additional variables to optimise.
- - Enhanced molecular ions and reduced fragmentation.
- - Fully automated in TOF-DS™ software.
Identify isomers that elude all other GC–MS systems
- - Enhance your confidence in the identification of isomers that are indistinguishable at 70 eV.
- - Easily create complementary soft EI spectral libraries.
- - Integrate Select-eV into your workflow with the help of Markes’ soft EI library.
- - Reduce your reliance on retention indices.

