## Wikipedia - Electron capture ionization (en) Wikipedia - Ion source (en) electron capture detector

in gas chromatography
https://doi.org/10.1351/goldbook.E01981
A small @R05088@ containing 3H or 63Ni ionizes the molecules of the @C00863@ (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 @D01628@ (threshold) varies greatly according to the substances to be analysed and can reach a mixing ratio of $$10^{-12}$$. The linear dynamic range may be $$10^{4}$$ but the maximum measuring value generally lies below $$1\ \text{ppmv}$$.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2191 [Terms] [Paper]