Today there was another question about chromatography on “Yahoo! Answers” from naisy428:

What chemicals can be detected using a Gas Chromatography?

Here is my very short, simplified answer. There are actually two types of Gas Chromatography – Gas-Solid and Gas-Liquid depending on the kind of column is used:

  • GSC (Gas-Solid Chromatography) allows to separate and hence detect low-molecular-mass gases such as air component (nitrogen, oxygen, CO2), hydrogen sulfide, carbon monoxide, and nitrogen oxides.
  • GLC (Gas-Liquid Chromatography) – this type is very widespread in all fields of science and that’s why when people say “GC” they usually refer to gas-liquid chromatography. This type of GC is mostly used to determine organic compounds such as hydrocarbons, polynuclear aromatics, fatty acids, alcohols, ethers, essential oils or any other volatile compound. What GC can detect greatly depends on the column and detector used. Generally speaking, GC is not suitable for thermally unstable samples and inorganic compounds. For example, you cannot analyze a water sample on GC to test for heavy metals or halides.