This application note describes the direct thermal desorption of desirable and undesirable aroma compounds from edible oils. The oil sample is placed in a microvial from where it is directly thermally desorbed using a GERSTEL Thermal Desorption Unit (TDU). Volatile compounds are transferred to the GC/MS system while leaving the non-volatile oil matrix behind in the microvial, preventing it from reaching and contaminating the GC inlet and the GC column.

Different designs of microvials were evaluated for effectiveness of analyte transfer. Microvials with a slit at 1 cm from the bottom were found to be the best suited providing efficient and repeatable analyte transfer and sensitive determination of a wide range of compounds.