, Volume 38, Issue 5–6, pp 304–312 | Cite as

A theoretical model of the electron capture detector

  • J. Lasa
  • B. Drozdowicz
  • I. Śliwka


This paper reports a theoretical model of the ECD detector. The model presented here can be used to examine the influence of pulse parameters on the current and signal characteristics of the detector. On the basis of this model it was found that a space charge is created in the detector when it is supplied with pulse voltage. Due to the electric potential generated by the space charge, in the time between the pulses the electrons and negative ions move towards the detector electrodes. The ionization current of the detector is the sum of the electron current flowing to the anode under the influence of the supplied pulse voltage and the current flowing under the space charge potential in the time between the pulses. It was also found that the detector signal is the sum of the differences between those two currents caused by introducing the sample molecules to the detector. The model was tested for a detector with different electrode configurations which worked at temperature of 300 K or 573 K and which was supplied with nitrogen or Ar+10% CH4 as the carrier gas.

Key Words

Gas chromatography Electron capture detector Theoretical model of ECD 


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  1. [1]
    J. E. Lovelock, A. J. Watson, J. Chromatogr.,158, 123 (1978).Google Scholar
  2. [2]
    W. E. Wentworth, E. C. M. Chen, J. Chromatogr.,186, 99 (1976).Google Scholar
  3. [3]
    J. Rosiek, I. Śliwka, J. Lasa, J. Chromatogr.,137, 245 (1977).Google Scholar
  4. [4]
    W. A. Aue, S. Kapila, J. Chromatogr.,186, 1 (1980).Google Scholar
  5. [5]
    W. A. Gobby, E. P. Grimsrud, S. W. Warden, Anal. Chem.,52, 473 (1980).Google Scholar
  6. [6]
    J. Lasa, I. Śliwka, Chromatographia,27, 499 (1989).Google Scholar
  7. [7]
    J. Lasa, I. Śliwka, B. Drozdowicz, Chromatographia,32, 248 (1991).Google Scholar
  8. [8]
    I. Śliwka, Time constants of the ECD, (in preparation).Google Scholar
  9. [9]
    Numerical Recipes,W. H. Press, B. P. Flannery, S. A. Tenkolsky, W. T. Vetlering, Cambridge University Press, Cambridge-New York, New Rochelle, Melbourne-Sydney, (1988).Google Scholar
  10. [10]
    J. Lasa, I. Śliwka, Anal. Chem., (Warsaw)36, 341 (1991).Google Scholar
  11. [11]
    J. L. Pack, A. V. Phelps, J. Chem. Phys.,44, 187 (1966).Google Scholar
  12. [12]
    D. Smith, N. G. Adams, A. Alge, J. Phys. B: At. Mol. Phys.,17, 461 (1984).Google Scholar
  13. [13]
    A. Alge, A. G. Adams, D. Smith, J. Phys., B: At. Mol. Phys.,17, 3827 (1984).Google Scholar
  14. [14]
    L. G. Huxley, R. W. Cromton, The Diffusion and Drift of Electrons in Gases, (in Russian), MIR, Moskwa (1977).Google Scholar
  15. [15]
    E. W. McDaniel, Collision Phenomena in Ionized Gases, John Wiley and Sons, Inc., New York-London-Sydney (1967).Google Scholar
  16. [16]
    J. D. Cobine, Gaseous Conductors, Dover Publications, Inc., New York (1958).Google Scholar
  17. [17]
    A. V. Engel, M. Steenbeck, Elektrische Gasenladungen, Ihre Physik und Technik, Berlin, Verlag von Julius Springer (1932).Google Scholar

Copyright information

© Friedr. Vieweg & Sohn Verlagsgesellschaft mbH 1994

Authors and Affiliations

  • J. Lasa
    • 1
  • B. Drozdowicz
    • 1
  • I. Śliwka
    • 1
  1. 1.Institute of Nuclear PhysicsCracowPoland

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