Gas Chromatography is a method of analyzing an unknown liquid mixture by separating the components by boiling point

1. A liquid mixture of unknown compounds A and B is injected into a column with an inert gas (usually Helium) which pushes the liquid through the column into an oven (brown) where it vaporizes

2. The column is coated with a liquid with a high boiling point (green). The gas with the higher boiling point (B) will form stronger bonds with this liquid and experience drag as it moves along the wall. The column is wrapped into a spring-shape to increase the total distance the gases have to travel before reaching the detector. This will enhance the total separation of the gases.

• the molecular weight of the gas will also have effect on the speed of the gas as it moves through the column (smaller = faster)

3. Because the different gases move through the column at different rates, they will be measured at the detector at different times

• in the above example, there is more of compound A (higher incident intensity at detector) than compound B. The first peak is typically due to the solvent used and not the mixture of interest.