Solid phase microextraction with gas chromatography-mass spectrometry: a very rapid method for identification of volatile organic compounds emitted by Carum copticum.

The investigation of flower scent represents an important field of modern biological research which is directed towards special theories of biological recognition. The headspace solid phase microextraction coupled with gas chromatography-mass spectrometry was used to identify the volatile components of Carum copticum (C. copticum) cultivated in Iran. The compounds were identified according to their retention indices and mass spectra (EI, 70 eV). The effects of different parameters, such as the desorption time, the extraction temperature, the sample mass, the addition of salt, the pre-equilibration time and the extraction time, on the extraction efficiency were investigated. The optimized conditions were: the desorption time, 2 min; the extraction temperature, 58 degrees Celsius; the sample mass, 1.000 g in 4.0 mL 2.0 M NaCl solution; the pre-equilibration time, 25 min; the extraction time, 20 min. Finally, ten components were identified in the volatile components of C. copticum. The major components of C. copticum were thymol (68.2%), gamma-terpinene (13.9%), p-cymene (11.6%), myrcene (1.0%) and beta-pinene (0.6%). Precision of the proposed method is good and %RSD less than 14 was obtained.