Rapid preconcentration and enrichment techniques for the analysis of food volatile. A review

Preconcentration and enrichment techniques for volatile compounds are reviewed. Only rapid and cheap methods, applicable to food analysis are considered. The methods are grouped into two sampling modes: (i) dynamic headspace or purge-and-trap (solid, liquid, cold or solvent trap and direct thermal desorption), and (ii) SPME (including SBSE, HSSE and SPDE). All these extraction methods can be coupled to either gas chromatographs or electronic noses. The description of these techniques is made in the sense of their historical development. Where comparative studies have been carried out, advantages and disadvantages of the methods have been cited. In the last part, two tables give a representative but not exhaustive list of the preconcentration methods used for the analysis of dairy products.