- Analytical methods
- Gas chromatography
- Liquid chromatography
- Infrared spectroscopy
- Other spectroscopy
- Other methods
- Inductively coupled plasma
- Mass spectrometry
- Nuclear magnetic resonance
- Supercritical fluid
A Flame ionization detector (FID) consists of a hydrogen (H2)/air flame and a collector plate. The effluent from the GC column passes through the flame, which breaks down organic molecules and produces ions. The ions are collected on a biased electrode and produce an electrical signal. The FID is extremely sensitive with a large dynamic range, its only disadvantage is that it destroys the sample.
Flame ionization detectors are used for detecting hydrocarbons (HC) such as methane (CH4), ethane (C2H6), acetylene (C2H2) etc.
The sample to be analyzed is mixed with a special burner fuel, hydrogen (H2), hydrogen plus helium (He) or hydrogen plus nitrogen (N2). Ions and electrons that were formed in the flame enter the electron gap, decrease the gap resistance and thus permit a current to flow into the external circuit. The current is proportional to the rate of ion formation which depends on the hydrocarbon concentration in the gases and is detected by a suitable electrometer and displayed on an analogue output.
The FID gives a rapid, accurate and continuous reading of total HC concentration for levels as low as ppb.
For more information, download our informational data sheet