Determination of potential flavour additives in tobacco products by headspace solid phase microextraction - gas chromatography-mass spectrometry (HS-SPME-GCMS)
Rapid screening techniques for the detection of flavour components in tobacco using headspace - solid phase microextraction - gas chromatography mass spectrometry (HS-SPME-GCMS) are primarily qualitative, requiring additional analysis to provide the quantitative information for specific compounds of interest. Using isotope-labeled “internal standards”, reference tobacco products, and standards for selected compounds (33) representative of potential flavour additives in tobacco products, the same technique can be applied to provide quantitative results for these targeted compounds.
The procedure uses 0.5 grams of tobacco product placed into a 10 mL headspace vial. The sample is spiked with a fiber performance check (FPC) solution (d6-benzene, d5-acetophenone, d5-benzophenone) and 3.0M aqueous potassium chloride. The sample is incubated for 5 minutes at 50°C with periodic agitation, then the headspace extracted onto a PDMS-DVB fiber. Desorption onto a 60 m x 0.25 mm ID x 0.25 µm DB-5MS column occurs at 250°C. Chromatographic separation is achieved over a 60 minute run time with the mass spectrometer operated in the range from 35–500 m/z.
Calibrations for the 33 potential flavour additives were divided into two levels. Low level calibrations range over single order of magnitude from as low as 1 ng for isoamyl isovalerate. The high level calibrations range over two orders of magnitude up to 800 µg for vanillin. The limit of detection (LOD) is estimated by calculating the root mean square error (RMSE) of a calibration curve prepared by fortifying a reference tobacco. Other than menthol, no flavour compounds considered to be at additive levels were found in the series of products tested using this technique.