3. Extraction and sample preparation

The quality of GC/olfactometry results is highly dependent on the method of extraction and/or sample preparation prior to analysis.

The choice of the most suitable method is dictated by two main factors: the nature of the sample and the purpose of the analysis. The aim is to obtain the most representative sample, from an olfactory point of view, of the matrix under study, while limiting the extraction of non-volatile compounds that could interfere with gas chromatographic analysis.

• When extracting an atmosphere (gaseous sample), two techniques can be used: direct or indirect sampling. In the case of direct sampling, the initial product is already in gaseous form. It is collected using gas syringes or inert bags such as nalophane ^® (