Gas Chromatography (GC) Detectors

Introduction

After the components of a mixture are separated using gas chromatography, they must be detected as they exit the GC column. The links listed below provide the details of some specific GC detectors. The thermal-conductivity (TCD) and flame-ionization (FID) detectors are the two most common detectors on commercial gas chromatographs. The requirements of a GC detector depends on the separation application. For example, one analysis might require a detector that is selective for chlorine-containing molecules, another analysis might require a detector that is non-destructive so that the analyte can be recovered for further spectroscopic analysis.

Specific GC detectors

Atomic-emmision detector (AED)

Chemiluminescence detector

Electron-capture detector (ECD)

The ECD is as sensitive as the FID but has a limited dynamic range and finds its greatest application in analysis organic molecules that contain electronegative functional groups, such as halogens, phosphorous, and nitro groups.

Flame-ionization detector (FID)

The FID is extremely sensitive with a large dynamic range, its only disadvantage is that it destroys the sample.

Flame-photometric detector (FPD)

Mass spectrometer (MS)

Mass spectrometers provide structural information to identify the analyte in a chromatographic peak.

Photoionization detector (PID)

Thermal conductivity detector (TCD)

The TCD is not as sensitive as other dectectors but it is non-specific and non-destructive.