FLAME IONIZATION DETECTOR (FID)



Flame Ionization Detector (FID) is one of the most used detectors for gas chromatography (GC). The application area is wide such as in petrochemcal, food science, biochemistry, natural product, polymer, fiber and etc. Flame ionization detectors are extremely sensitive and have a wide range of linearity. The only disadvantage is that it consumes the sample. In an FID, the sample undergoes a combustion in a hydrogen/synthetic air fl ame. Ions and free electrons are formed in the fl ame. The charged particles produce a measurable current flow in the gap between two electrodes in the detector. The resulting current flow is of greater strength than the signal produced by the pure carrier gas and the fuel gas flame alone. This signal differential provides information about the sample. The current is proportional to the information which depends on the composition of the separated sample.