Question

If a student submitted a sample of water for GC analysis because they were confused about what was their organic layer and what was their aqueous layer, would a solvent peak be observed in the gas chromatogram of the sample assuming it was analyzed? Remember our gas chromatograph uses a FID.

Answer 1

Flame ionization detection (FID) is a good general detector for organic compounds.

It detects the amount of carbon in a sample and the carbon ions are produced by combustion.

The total amount of ions is directly proportional to the amount of carbon in the sample

FID is a destructive detector because the entire sample is pyrolized.

FID is unaffected by water and non combustible gases.

so, when a water sample is analyzed by GC mathod, the peak depends on the amount of organic matter in the sample.

Yes, a solvent peak is observed.