GC-NPD P-pesticide

GC-NPD
Detector Type: Nitrogen Phosphorus detector

This detector is specific to Phosphorus compound, which is suitable for detection of phosphorus pesticide (same function to ECD detecting Cl-pesticide)
The detector works by electrically heating a glass bead containing an alkali metal (Rb) until electrons are emitted. These electrons are captured by stable intermediates to form hydrogen plasma. Phosphorus pesticide is ionised and directed into this plasma. An electrical field directs these resulting ions to an anode creating an increased current. The fluctuation of current will create a chromatogram.
http://www.encolabs.com/gc1.htm

Plasma: The fourth state of a matter (S,L,G,Plasma), gas becomes so hot, electron breaks away from atom.