GC-FID analysis (gas chromatography with flame ionization detection)
GC-FID analysis is a gas chromatography technique used to separate and quantify volatile and semi-volatile organic compounds. Recognized for its sensitivity, reproducibility, and selectivity for carbon compounds, GC-FID is an essential method for quality control and characterization of complex formulations in various sectors, including plastics, cosmetics, pharmaceuticals, chemicals, food processing, and environmental applications.
What is GC-FID analysis?
GC -FID (Gas Chromatography – Flame Ionization Detection) is a two-step analytical method: separation of the compounds in a sample by gas chromatography , followed by specific detection by flame ionization .
After vaporization, the analytes are carried by a carrier gas (often helium or nitrogen) through a capillary column . Each compound migrates at a different rate depending on its volatility and its interaction with the stationary phase, thus allowing their separation.
At the column outlet, the carbon molecules are burned in a hydrogen flame , generating ions that are detected by an electrometer. The signal intensity is directly proportional to the concentration of the compound.
How the GC-FID method works
GC-FID analysis follows these steps:
- Sample preparation: liquid or solid, sometimes diluted in an organic solvent.
- Injection: the sample is vaporized instantly in the heated injector.
- Chromatographic separation: the compounds migrate through a heated capillary column, according to their volatility and polarity.
- Flame ionization detection: carbon compounds are burned in a hydrogen flame. The ions formed are collected by electrodes, generating an electrical signal.
- Interpretation of the chromatogram: each peak represents a compound; its area is proportional to the concentration.
Technical specifications of the GC-FID
- FID detector : very sensitive to carbon-containing molecules (not sensitive to water, CO₂, H₂…)
- Detection limits : on the order of ppm to ppb depending on the compounds
- Linearity range : very wide, facilitating quantification
- Atmosphere : flame fueled by hydrogen and air
- Column temperature : from 40 °C to 300 °C or more, depending on the nature of the analytes
- Associated standards : European Pharmacopoeia, USP <467>, ISO 16000, validated internal methods
For which matrices?
GC-FID analysis is ideal for matrices containing or releasing volatile organic compounds:
Main industrial applications
GC-FID is widely used in R&D, quality control and regulatory expertise in the following sectors:
Léa Géréec
Technical and scientific advisor
