Gas Chromatography: Types of Detectors-II

Compounds containing nitrogen or phosphorous can be selectively detected by the thermionic or nitrogen-phosphorus detector.

Here, the ignited column effluent flows around a heated alkali bead, giving rise to large currents.

Similarly, the flame photometric detector selectively detects sulfur and phosphorus-containing compounds.

Combustion in a hydrogen flame forms luminescent species whose characteristic emissions are isolated using filters and measured by a photomultiplier tube.

The photoionization detector uses high-energy ultraviolet radiation to ionize the analytes. The resulting ions are detected using electrodes that generate a signal for the recorder.

In the element-selective atomic emission detector, the sample is atomized in a plasma. The atomic emission spectra from the excited atoms are then characterized.

The electrolytic conductivity detector transforms the gaseous eluents into ions in a liquid solution and uses a conductivity cell to measure the conductivity of ions.

Other detectors include GC coupled with mass spectrometry and FTIR spectroscopic techniques.