Innovative Technology For Trace Organic Analysis
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Time-of-flight mass spectrometer for GC and GC×GC with variable-energy electron ionisation

Our two BenchTOFs are the ultimate trace gas detectors: highly sensitive, very reliable and convenient to use...

Peter Boeker, University of Bonn, Germany

Who uses the BenchTOF-Select?

Users of BenchTOF-Select are analysts who need the extra confidence that comes with soft ionisation, but don't want the hassle of ion-source changes and can't afford to compromise on sensitivity.

The additional confidence delivered by soft EI has proven vital for challenging petrochemical and fragrance analyses, especially for the identification of isomers that are indistinguishable at 70 eV.


Mass spectral comparison showing Select-eVTandem Ionisation on the BenchTOF-Select provides NIST-quality 70 eV and complementary soft electron ionisation in a single analysis, as shown here for a fragrance mixture.

Product benefits

  • Expand your analytical capability with Select-eV® – confidently identify unknowns and routinely distinguish between structurally similar compounds.

  • Acquire hard and soft ionisation data simultaneously using Tandem Ionisation® – for unparalleled productivity.

  • Enjoy greater confidence in identification, thanks to BenchTOF-Select’s reference-quality 70 eV spectra and complementary soft EI spectra.

  • Eliminate the hassle and expense associated with other soft ionisation techniques.

  • Expand your laboratory’s capability by improving detection of trace-level compounds in complex matrices.

  • Speed up analysis of complex samples with fast GC and GC×GC.

  • Streamline your instrument control, method development and data analysis with TOF-DS™ software and its optional ChromSpace® GC×GC module.


  • Unique Select-eV® and Tandem Ionisation® capability, giving complementary soft EI spectra with enhanced molecular ions and reduced fragmentation in a single run.

  • SIM-like sensitivity for trace-level analysis of targets and unknowns in a single run.

  • Reduced chemical noise/background, improving detection limits for target compounds.

  • Powerful TOF-DS™ software for instrument control and data analysis, including real-time processing and unlockable parameters for fast method development.

  • Sub-unit mass selectivity to eliminate matrix interferences and improve signal-to-noise ratios.

  • High-speed spectral acquisition ensuring compatibility with GC and GC×GC.

  • Robust ion source design – meaning source cleaning is recommended only once a year, as part of the routine annual service.

Other resources

Gallery Images

Lab view of TOF
TOF with Agilent
TOF with Thermo
TOF with Shimadzu
TOF with TD
GC-TOF MS in lab
MS sprectral comparison
Nondecane isomers with Select-eV
Click on an image for a larger view.
Markes International Ltd
Gwaun Elai Medi-Science Campus
Tel: +44 (0)1443 230935
Markes International GmbH
Bieberer Straße 1-7
63065 Offenbach am Main
Tel: +49 (0)69 6681089-10
USA (West)
Markes International, Inc.
2355 Gold Meadow Way
Gold River, Sacramento
California 95670
Tel: +1 866-483-5684 (toll-free)
Markes Instruments (Shanghai) Co., Ltd
Unit 1002, Building 1
No.418, Guilin Road
Shanghai 200233
P.R. China
Tel: +86 21 5465 1216
Part of Schauenburg International

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