8. Glossary

Flame Ionization Detector (FID)

Detector for organic compounds in the gas phase. The sample is passed through a high-temperature hydrogen flame, which ionizes the C-H bonds. The quantity of ions produced is collected between two electrodes. The ionization current measured depends on the number of carbon atoms in the compounds, the nature of the bonds and the nature of the atoms bonded to the carbon. A product-specific calibration curve quantifies the quantity or concentration of the target compound in the sample. The detector is generally calibrated with methane or propane to give a carbon equivalent in the gas analyzed. A gas chromatograph (upstream) to separate the products can be coupled with the FID. Compound identification in a GC-FID combination is based on the analogy of retention times and quantification using a calibration curve based on peak area or peak...