Markes International Shapes the Future of GC–MS with Launch of New Variable-Energy Electron Ionization Technology
03 Feb 2014

Markes International (Llantrisant, UK), a world leader in instrumentation for trace organic analysis, has announced the launch of a variable-energy electron ionization source technology for GC–MS, Select-eV®.

By enabling the energy of ionizing electrons to be changed, Select-eV breaks new ground in the field of GC–MS. It allows the production of reference-quality electron ionization mass spectra with conventional full-fragmentation patterns, and repeatable ‘soft-ionization’ spectra exhibiting reduced fragmentation and an enhanced molecular ion.

Maintain Sensitivity without System Reconfiguration

Previous attempts to develop soft electron ionization have been compromised by a dramatic drop in sensitivity. Other approaches to soft ionization have also been limited by the inconvenience of reagent gases or source exchange. Select-eV overcomes all these problems by maintaining or enhancing sensitivity, without the need to reconfigure the system or add reagents.

Nick Bukowski, Mass Spectrometry Business Unit Manager at Markes, said “Using Select-eV, the desired ionization energy is simply selected as part of the method setup in the controlling software. Energies can be varied anywhere from standard 70 eV down to 10 eV. The molecular ion is enhanced at lower energies but a degree of structurally significant fragmentation is also maintained. This makes Select-eV perfect for any GC–MS analyst needing further confirmation of compound identity, or wanting to distinguish between compounds with spectra that are very similar at 70 eV.”

Increase Signal-to-Noise Ratios

Bukowski added “Lowering the energy of electron ionization usually causes a dramatic drop in sensitivity, but Select-eV overcomes this problem. In fact, the signal-to-noise ratios of many compounds are increased at lower energies. This is a crucial advantage of Select-eV for trace analysis and for challenging samples such as the complex mixtures of hydrocarbons routinely investigated in the petrochemical industry.”

Select-eV is available with the BenchTOF range of time-of-flight mass spectrometers from Markes International, which enjoy increasing popularity in the GC–MS field for their high degree of sensitivity and the production of ‘reference-quality’ spectra, alongside numerous productivity advantages for the analyst.


Launched at HTC-13

Markes launched the Select-eV and the newly updated BenchTOF line of mass spectrometers at the HTC-13 conference in Bruges, Belgium, January 28th-31st 2014. The company will also presented their world-leading range of innovative thermal desorption technology for automated extraction/concentration of trace organics in air and materials.

Markes International manufactures specialist analytical instrumentation for trace organic analysis It is renowned as a global market leader for analytical thermal desorption and for developing ground-breaking time-of-flight MS technology for gas chromatography. In January 2013, Markes became part of the Mulheim-based German family business Schauenburg International Group, and also has additional technical support centres in the USA and Germany. For further information on Markes International, please click on the company website or more info links below.

Request Info


Company website

Markes International Ltd
profile photo

Sarah Thomas
Editorial Assistant     




Write a Review

Join the Global SelectScience Community Today! It’s FREE!

Helping you make informed decisions about the latest lab products and technologies:

  • Be the first to learn about new technologies
  • 10,000+ trusted product reviews from your peers
  • Compare 500,000 products and manufacturers
  • Get exclusive buying tips from experts
  • Find solutions fast: 10,000+ Application Notes, Webinars and Videos

Connect with 250,000 scientists... All in one place!

Become a member today!