Determination of encapsulated menthol flavour using thermal desorption gaschromatography

The analysis of methol in encapsulated products is challenging due to the n ature of the encapsulating matrices and the volatility of the analyte. Norm al sampling/extraction procedures cannot be applied to the different types of menthol encapsulated products, due to variable extraction efficiencies o f the analyte. This paper details the extraction and analysis of menthol fl avour using a two stage thermal desorption GC process. This two stage therm al desorption system, using a Tenax TR packed cold trap, enables a narrow b and of the extracted menthol to be focused onto the GC column. The method s howed linearity in the range of 0.2-0.8 mg of menthol with a correlation co efficient greater than 0.999. Average instrumental precision of 3% RSD was determined and method precision was in the range of 2.1-9.4% RSD. This meth od was specific to menthol showing no interfering peaks. All the menthol wa s extracted in one extraction step. The specific analysis of menthol in enc apsulated products allowed comparison of the efficiency of encapsulating pr ocesses, by comparing menthol loading values. RSD values for the different microparticles also indicate the relative homogeneity of the systems.