Non-radioactive electron-capture detector

Abstract A non-radioactive electron-capture detector is described which uses a thermionic emitter as a source of electrons. The use of this source allows a unique mode of operation which has greatly enhanced sensitivity, yet at the same time allows a large dynamic range. A signal-to-noise ratio of 180 to 1 has been obtained at the 1-pg level, together with a dynamic range of six orders of magnitude. It appears that with this method it is possible to detect femtogram quantities.