Determination of volatile compounds in antioxidant rosemary extracts by solid-phase microextraction and gas chromatography

A method based on headspace solid-phase microextraction (HS-SPME) and gas chromatography for determining residual volatile compounds in commercial rosemary (Rosmarinus officinalis) extracts is proposed. Twenty-four volatile compounds were identified by gas chromatography-mass spectrometry, and 12 of them were selected and quantified by HS-SPME gas chromatography-flame ionisation detection. The influences of the HS-SPME variables, such as type of fiber, water addition to the solid sample, incubation time and temperature, and extraction time were studied. The final working conditions were a 50/30 mu m divinylbenzene-carboxen-polydimethylsiloxane fiber, water addition, 15-min incubation at 70 degrees C and 60-min extraction at room temperature. The signals obtained by HS-SPME were higher than those recorded by static headspace. The features of the method was performed by both external standard ( using aqueous volatile compound standard solutions) and standard addition, and the results obtained were compared.