Detection of radiolytic hydrocarbons by supercritical fluid extraction and gas chromatographic–mass spectrometric analysis of irradiated cheese

Supercritical fluid extraction (SFE) was used for the isolation of characteristic hydrocarbon patterns formed by irradiation of fat-containing foods. The proposed method has the advantage of not requiring the use of organic solvents since analyte recovery is obtained simply by thermal desorption of the solutes previously retained in an adsorbent material, packed in the trap of the SF extractor, and its subsequent GC–MS analysis. Thereby, the risks of contamination with different compounds, as well as of losses by coevaporation with the solvent, involved in the use of conventional techniques are avoided. The method is capable of verifying, in less than two hours, whether a cheese sample has been (or not) submitted to an irradiation treatment on the basis of the detection of four radiolytic markers, namely n-pentadecane, 1-tetradecene, n-heptadecane, and 1-hexadecene.