Solid-phase microextraction gas chromatographic mass selective detection analysis of selected sources of menthol

Manual solid-phase microextraction (SPME) coupled with gas chromatography-mass selective defection has been shown to be a rapid, precise, and reliable method for testing the origin and purity of menthol samples. Exposure of a 65-μm carboxenpolydimethylsiloxane fiber to the headspace above a menthol sample held at 50°C in a sealed vial provides for excellent signal-to-noise responses for a variety of volatile components. Detection differences in menthol compositions are based on documenting predictable changes in the ratios of identified and/or unknown components adsorbed onto the SPME fiber. Differences in composition can be detected as a function of manufacturing site using this approach. In addition, the presence of added synthetic menthol can be detected in the natural samples employing the same principle, thus assisting in determining the purity of the natural menthol.