Innovative Technology For Trace Organic Analysis
TEL: +44 (0)1443 230 935
Mobile Menu


Award-winning soft electron ionisation technology for GC–MS

The combination of GC×GC and mass spectra at low and high ionisation energies confers unparalleled power to identify specific isomers within our chromatograms

Dr M. Salim Alam, University of Birmingham, UK

Harness the power of Tandem Ionisation®

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® (US patent number 9,786,480) 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.

Download our Application Notes...





Gallery Images

Benzophenone mass spectral comparison
Mass spectral comparison
Nopndecane isomers with Select-eV
Click on an image for a larger view.
Markes International Ltd
Gwaun Elai Medi-Science Campus
CF72 8XL, UK
Tel: +44 (0)1443 230935
Markes International GmbH
Schleussnerstrasse 42
D-63263 Neu-Isenburg
Tel: +49 (0)6102 8825569
USA (West)
Markes International, Inc
2355 Gold Meadow Way
Gold River
California 95670
Tel: 866-483-5684 (toll-free)
Part of Schauenburg International

Hello, how can we help you today?