GC-FID (gas chromatography with flame ionization detection) analysis
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: plastics, cosmetics, pharmaceuticals, chemicals, food processing, and the environment.
What is GC-FID analysis?
GC -FID (Gas Chromatography – Flame Ionization Detection) is a two-step analytical method: separation of 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 speed depending on its volatility and its interaction with the stationary phase, which allows their separation.
At the column outlet, the carbon molecules are burned in a hydrogen flame , generating ions 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: Compounds migrate through a heated capillary column, depending on 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 characteristics of the GC-FID
- FID detector : very sensitive to molecules containing carbon (not sensitive to water, CO₂, H₂, etc.)
- Detection limits : in 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 : 40°C to 300°C or higher, 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
