Topics - GC Detector
The GC detector is a sensing device used to monitor the concentration profiles of solutes eluted from a gas chromatography column. There are a considerable number of such devices described in the literature that function by measuring many different properties of the eluting carrier gas. Some examples of the early GC detectors would be the thermal conductivity detector
that measures the thermal conductivity and specific heat of the eluting gas, the gas density balance
(the first in-line detector to be described) that responds to the change in vapor pressure of the gas and the flame thermocouple detector
that measures the calorific value of the eluting gas. Today the most popular GC detector is the flame ionization detector followed probably by the nitrogen phosphorous detector and the electron capture detector. GC detectors can be extremely sensitive and the electron capture detector is capable of sensing fluorinated hydrocarbons at concentrations less than 10-12 g per ml. There are a number of GC detectors based on different ionization processes all of which provide very high sensitivities. Due to the high sensitivities that are available from the GC detectors the technique of gas chromatography is use extensively in forensic chemistry, pollution studies and food analysis toxicology.