Preferred Label : electron capture detector;
Detailed label : electron capture detector in gas chromatography;
IUPAC definition : A small radioactive source containing sup 3 /sup H or sup 63 /sup Ni ionizes the
molecules of the carrier gas (nitrogen or argon–methane), and a potential difference
creates a small current. This current is reduced when an electronegative substance
(such as a halocarbon) is introduced. The reduction in current is a measure of the
concentration of the electronegative substance. The detection limit (threshold) varies
greatly according to the substances to be analysed and can reach a mixing ratio of
10E-12. The linear dynamic range may be 10E4 but the maximum measuring value generally
lies below 1 ppmv.;
Origin ID : E01981;
See also
A small radioactive source containing sup 3 /sup H or sup 63 /sup Ni ionizes the
molecules of the carrier gas (nitrogen or argon–methane), and a potential difference
creates a small current. This current is reduced when an electronegative substance
(such as a halocarbon) is introduced. The reduction in current is a measure of the
concentration of the electronegative substance. The detection limit (threshold) varies
greatly according to the substances to be analysed and can reach a mixing ratio of
10E-12. The linear dynamic range may be 10E4 but the maximum measuring value generally
lies below 1 ppmv.
