[Heated oils : analytical aspects].

About four hundred compounds from fatty acid molecule's clivage, oxidation and polymerisation have been isolated from heated fats. Because of this complexity, two steps of analysis will be considered: --an elaborate analysis: its aim is a best separation and characterisation of the components. It takes a long time and a great deal of means. Required for a basis knowledge, it is a guide for a control analysis; --a control analysis determinating the chemical compounds of a same family or with a similar structure. Thanks to specific methods oxiacids or oxidized glycerides and some cyclic-monomeres are determinated. The column chromatographies are able to separate unaltered compounds from the total polar artefacts, a gas chromatography with an internal standard is used for determing the cyclic monomeres. Heated fats and oils are also tested by a number of methods which involve identification of chemical and physical characteristics. Some examples are given.