Optimisation of solid phase microextraction (SPME) for the analysis of volatile compounds in dry-cured ham

Solid phase microextraction (SPME) has been shown to be an effective tool for analysing volatile compounds. The aim of this study was to optimise the conditions for the application of SPME in the analysis of volatile compounds in dry-cured ham. The effects of exposure time and fibre coating were investigated while maintaining the dry-cured ham at 30degreesC to avoid artefact generation due to possible temperature effects. A divinylbenzene/Carboxen on polydimethylsiloxane (DVB/CAR/PDMS) coating showed the best extraction performance for medium- and high-molecular-weight analytes, whilst a Carboxen on polydimethylsiloxane (CAR/PDMS) coating gave the best results for low-molecular-weight compounds. A total of 70 different compounds were extracted by the two fibre coatings and identified. Sixty compounds were extracted by the DVB/CAR/PDMS fibre, whilst only 41 of these were found with the CAR/PDMS fibre. On the other hand, 10 additional volatile compounds were extracted by the CAR/PDMS coating, all of them being of low molecular weight. Two of the major compounds extracted, hexanal and 2-pentanone, were found in high proportion in both fibre coatings. The extraction yields of dry-cured ham volatile compounds varied according to the fibre coating used and the time of exposure. Therefore extraction conditions should be selected depending on the objective of the study. (C) 2002 Society of Chemical Industry.