Gas Chromatography employs partition between a gas phase and a functionalised immobilised liquid phase to achieve separation. Owing to the length of the capillary columns, high resolution can be achieved.
You can find a column here that will suite your needs from hydrocarbons and pesticides to FAME and residual solvents
These are key consumbale items which require attention to optimise your chromatography.
You need to calibrate in order to quantify and for this you need high quality reference materials.