Carrier Gas
Definition
The inert mobile phase that sweeps the sample through the column. Helium is traditional and gives the best peak shape on capillary columns, hydrogen is faster and cheaper but flammable, nitrogen is the budget option used mostly with packed columns.
Related terms
- Capillary Column
- A fused silica tube 15 to 60 m long with an internal diameter of 0.25 to 0.53 mm and a stationary liquid...
- Derivatisation
- A pre-injection chemical step that converts polar, non-volatile or thermally fragile analytes into volatile, GC-friendly derivatives. Silylation with BSTFA is the most...
- ECD
- Electron capture detector. A Ni-63 radioactive source produces a baseline electron current that is reduced when electron-affinic species (halogens, nitro groups, peroxides)...
- FID
- Flame ionisation detector. A hydrogen-air flame ionises C-H bond containing analytes and a collector electrode reads the ion current. Near-universal for organic...
- Headspace GC
- Gas chromatography in which the sample (blood, urine, vitreous) is sealed in a vial, equilibrated at a fixed temperature, and a portion...
Explained in
- Gas-Liquid Chromatography (GLC): Columns, Carriers and DetectorsThe inert mobile phase that sweeps the sample through the column. Helium is traditional and gives the best peak shape on capillary columns, hydrogen is faster...