ISSN:
1436-5073
Keywords:
electron capture detector (ECD)
;
electron oscillation
;
AC-ECD
;
argon-methane
;
non-homogeneous ECD kinetics
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The oscillation of electrons—as driven by AC polarization—can be used to extract a high-sensitivity signal from a conventional electron capture detector. For example, hexachloroethane was detected at a hypercoulometric ratio of 2.0 F/mol, down to ca. 60 fg/s (S/N=3) and with a linear range in excess of two orders of magnitude. The change in carrier gas from nitrogen to argon-methane produced the expected order-of-magnitude increase in optimum oscillation frequency. Anab initio simulation of potentials and ion populations in a heterogeneous electron capture system under a high-frequency AC regime provided further insight into the detector's mechanism: Hypercoulometric response is mainly caused by increased cation-electron recombination in the plasma region, owing to a decreased field gradient and an increased cation concentration.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01236089
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