Gas chromatography detectors
Gas chromatography (GC) detectors are classified as general or selective. General detectors include the thermal conductivity detector (TCD), which detects both organic and inorganic compounds by measuring changes in thermal conductivity, and the flame ionization detector (FID), which is highly sensitive to organic compounds but destroys analytes during detection. Selective detectors include the nitrogen–phosphorus detector (NPD) for nitrogen- and phosphorus-containing compounds and the electron capture detector (ECD) for compounds with electronegative groups, such as halogens. Gas chromatography–mass spectrometry (GC/MS) combines separation and mass analysis, providing both compound identification and highly sensitive detection.