School of Chemistry, Tel Aviv University, Israel

GC-MS with Cold EI and Its Several Enhancement Technologies – Innovations made in Israel

Gas chromatography mass spectrometry (GC-MS) is a widely used analytical technology. The most significant shortcomings of GC-MS are the often weak or absent molecular ions and the inability to analyze low volatility and thermally labile compounds.
We developed GC-MS with Cold EI that is based on electron ionization of vibrationally cold molecules in supersonic molecular beams (SMB) (hence the name Cold EI) in a contact-free fly-through ion source.
Cold EI improves all the performance aspects of GC-MS and provides enhanced molecular ions, best sample identification, extended range of compounds and applications amenable for analysis, faster analysis, uniform compound independent response and superior sensitivity particularly for difficult to analyze compounds.
We also developed a range of GC-MS enhancement technologies that each can work with standard GC-MS but excels with Cold EI including:

  1. Electron ionization LC-MS – providing library based identification at the isomer level, uniform response and absence of ion suppression for LC-MS. Our EI-LC-MS is based on minor modifications of the GC-MS with Cold EI interface. Recently, we also combined GC-MS and LC-MS with Cold EI in one system with method based mode changing.
  2. TAMI software for the provision of elemental formula from quadrupole based GC-MS and LC-MS data files. It excels with Cold EI due to availability of molecular ions for extended range of compounds.
  3. ChromatoProbe sample introduction device for both MS probe operation and thermal desorption inlet with many benefits. Over 4000 units are in worldwide use.
  4. Low thermal mass fast GC for enabling sub-one-minute full GC-MS analysis time.
  5. Open Probe Fast GC-MS – Real time analysis with separation and NIST library identification. It is commercially available by Agilent under the name QuickProbe.
  6. Pulsed flow modulation GCxGC-MS which provides with Cold EI ultimate level of sample identification in complex mixtures.

Aviv Amirav Ph.D. 
Date and Place of Birth: 1950, Israel
IDF (Israeli) Military Service: 1968-1971
Marital Status (No. of children): Married, 2 children
Education: Ph.D. was received in 1979 from Tel Aviv University, School of Chemistry, with Summa cum Laude. Title of Dissertation “Isotope Separation and R.F. Spectroscopy from Supersonic Molecular Beams”
Current Position: Professor of Chemistry at Tel Aviv University from 1989.
Chair: Incumbent of the Ratner Family chair in Analytical Chemistry from 2007
Contact Info: Email: Phone: +9723-6408253 Cell +972-54-5645742
Personal Web site:
Major International Awards:

  1. The Heinrich Emanuel Merck Prize Given at the opening ceremony of Euroanalysis VIII at Edinburgh Scotland, September 1993. The Award was for “Achievements in Analytical Chemistry”, given on our work “Pulsed Flame Photometer – A Novel Gas Chromatography Detector”
  2. HTC Award for “The Most Outstanding and Innovative Work in the Field of Hyphenated Chromatographic Techniques”. The HTC Award was given at the closing ceremony of the HTC 7 meeting in Brugge, Belgium, February 8th 2002. It was given on our development of GC-MS and EI-LC-MS with Supersonic Molecular Beams.

Publications: 197 peer review papers plus 52 booklets, application notes and other non-peer review publications plus 58 detailed articles in the Advanced GC-MS Blog Journal.
My h index is 47 in ISI and 55 in Google scholar with 8505 citations.

Patents: 20 Patents in 59 countries. Two patents, on the PFPD and ChromatoProbe, are in worldwide use as commercially available products by few vendors. Over 4000 PFPDs and 1600 ChromatoProbes are in worldwide use. Agilent introduced in 2019 and is selling our Open Probe Fast GC-MS under the name QuickProbe.

Research Grants: 48 external grants were received during 1981-2022 with total grant money of over 5.5 Million Dollars.

Current Research Group Size: Three Ph.D. graduate students.

Graduate Students and Postdoctoral Fellows Supervised: 12 M.Sc. Students, 20 Ph.D. students and 5 postdoctoral fellows. My previous Ph.D. student Eliezer Kolodney became a Professor of Chemistry at the Technion (Israel Institute of Technology) and my previous postdoctoral fellow Sergey Cheskis became a Professor of Chemistry at Tel Aviv University.

Annual Meeting Organization: Isranalytica, the annual meeting of the Israel Society of Analytical Chemistry. I am a member of the organizing committee from the meeting conception and several times Chairman or Co-Chairman or Vice Chairman of the meeting. Isranalytica is by far the biggest Chemistry meeting in Israel, attended annually by over 3200 people. For further details on Isranalytica please visit and its summary page.

Research Vision: My research is aimed towards the development of novel analytical instruments and their related methods to aid the analysis of broad range applications. My research focus is GC-MS with Cold EI in order to revolutionize the GC-MS area with it. Special emphasis is given to collaborations with the international analytical instrument industry in order to obtain wide spread use of my scientific developments and inventions and to achieve this way real impact on mankind.

Selected recent three years publications (2020-2022)

  1. A.B. Fialkov, S.J. Lehotay, and A. Amirav “Less than one minute low-pressure gas chromatography – mass spectrometry” J. Chromatogr. A. 1612, 460691 (2020).
  2. K. Margolin-Eren, A.B. Fialkov, U. Keshet, S. Tsizin, and A. Amirav “Doubly charged molecular ions in GC-MS with Cold-EI” J. Am. Soc. Mass Spectrom. 31, 347-54 (2020).
  3. A.B. Fialkov, E. Ikonen, T. Laaksonen, and A. Amirav “GC-MS with photoionization of cold molecules in supersonic molecular beams – Approaching the softest ionization method” J. Mass Spectrom. 55, e4516 (2020).
  4. S. Tsizin, A.B. Fialkov, and A. Amirav “Electron ionization mass spectrometry for both liquid and gas chromatography in one system without the need for hardware adjustments” J. Am. Soc. Mass Spectrom. 31, 1713-21 (2020).
  5. S. Tsizin, A.B. Fialkov, and A. Amirav “Analysis of impurities in pharmaceuticals by LC-MS with cold electron ionization” J. Mass. Spectrom. 55, e4587 (2020).
  6. A. Amirav, A.B. Fialkov, K.J. Margolin Eren, B. Neumark, O. Elkabets, S. Tsizin, A. Gordin, and T. Alon “GC-MS with Cold-EI: Bridging the gap between GC-MS and LC-MS” Current Trends in Mass Spectrometry, supplement to LCGC North America, 18, 5-15 (2020).
  7. K. Margolin-Eren, O. Elkabets, and A. Amirav, “A comparison of electron ionization mass spectra obtained at 70 eV, low electron energies and with Cold-EI and their NIST library identification probabilities” J. Mass Spectrom. J. Mass Spectrom. 55, e4646 (2020). DOI: 10.1002/jms.4646
  8. Tal Alon and Aviv Amirav “A Comparison of Isotope Abundance Analysis and Accurate Mass Analysis in their Ability to Provide Elemental Formula” Submitted to J. Am. Soc. Mass Spectrom. 32, 929-935 (2021). DOI: 10.1021/jasms.0c00419
  9. Aviv Amirav, Alexander B. Fialkov, Alexander Gordin, Oneg Elkabets and Ksenia J. Margolin Eren “Cold Electron Ionization (EI) Is Not a Supplementary Ion Source to Standard EI. It is a Highly Superior Replacement Ion Source” Critical Insight paper in J. Am. Soc. Mass Spectrom. 32, 2631-2635 (2021). DOI: 10.1021/jasms.1c00241.
  10. Ksenia J. Margolin Eren, Harry F. Prest and Aviv Amirav “Nitrogen and Hydrogen as Carrier and Make-up Gases for GC-MS with Cold EI” J. Mass Spectrom. 57, e4830 (2022). DOI: 10.1002/jms.4830
  11. Benny Neumark, Oneg Elkabets, Gabi Shefer, Assaf Buch, Naftali Stern and Aviv Amirav “Whole Blood Analysis for Medical Diagnostics by GC-MS with Cold EI” J. Mass Spectrom. 57, e4873 (2022). DOI:10.1002/jms.4873 This paper was selected to be the Featured Article of the July 2022 issue of Journal of Mass Spectrometry