Ionization detector pulsed discharge electron capture

The pulsed discharge electron capture detector is an extension of the previously discussed pulsed discharge helium ionization detector, a... 

The ECD used to establish the kinetic model was custom-built. Affordable commercial ECD and negative-ion gas chromatograph chemical ionization mass spectrometers are now available. Thus in order for an investigator to use these techniques, it is simply a matter of calibrating the instrument by reproducing the experimental results to verify that no artifacts result from the equipment. The major work described in this book was conducted with the radioactive ECD. The mechanisms for the pulsed discharge electron capture detector are the same as with the radioactive ECD that is now commercially available [4]. We have used commercial detectors and a quadrupole mass spectrometer with a home-made data collection system to determine electron affinities and to study the complexes of negative ions [5-9]. 

The sensor consists of two sections the upper section where the discharge takes place has a small diameter and the lower section where the column eluent is sensed and the electron capturing occurs has a wider diameter. As with the pulsed discharge helium ionization detector, the potential across the discharge electrodes is pulsed at about 3 kHz with a discharge pulse width of about 45 psec for... 

Abbreviations GC, Gas Chromatography IRMS, Isotope Ratio Mass Spectrometry ECD, Electron Capture Detector FID, Flame Ionization Detector TCD, Thermal Conductivity Detector MS, Mass Spectrometry PDHID, Pulsed-Discharge Helium Ionization Detector mol. sieve, Molecular Sieve HP, Hewlett-Packard PE, Perkin-Elmer. 

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