Solid-phase microextraction gas chromatography-mass spectrometry determination of monoterpenes in honey

Solid-phase microextraction (SPME) using a 100 microm poly(dimethylsiloxane) (PDMS) fiber, followed by gas chromatography (GC-MS) determination, has been applied to the analysis of some monoterpenoids in honey. The extraction was performed by direct immersion of the fiber using a sampling period of 15 min with constant magnetic stirring (1100 rpm) and an extraction temperature of 20 degrees C. A 7 mL sample volume of an aqueous solution of honey with 25% of NaCl was placed in 15 mL glass vial fitted with screw cap and PTFE/silicone septum. Desorption was performed directly in the gas chromatograph injector port during 5 min at 250 degrees C using the splitless mode. The method is sensitive with detection limits between 11 and 25 microg L(-1), precise with coefficients of variation in the range 1.28 and 3.71%, and linear over more than one order of magnitude. The related conditions were used for honey sample analyses with recoveries between 71.8 and 90.9%. SPME remains an attractive alternative technique due to its rapidity and because it is a solvent free extraction method.