In foods heating processes induce a series of chemical reactions that include the very complex Maillard reaction, oxidation of lipids, and many others. Normally, these complex reactions result in a huge number of different reaction products, meaning that the expected concentrations are very low and are normally a challenge for the analytical chemist. A typical example is the group of heterocyclic aromatic amines that are formed from reactions of amino acids with carbonyl compounds and (in many cases) creatin. The heterocyclic amines are the most potent known carcinogens and the concentrations in heated meat are in the range of several ng/g. Depending on the heat load these can reach a few hundred mgs.