The chromatographic conditions were: He as the carrier gas, 210 C and 260 C injector and detector temperatures, 7 min at 45 C, heating ramp to 220 C at 18 C/min, and 12 min more at 220 C. At the end of the desorption process the sample was weighed with a 0.1 mg precision balance .
Calibration was done by injecting known amounts of carvacrol or citral in the desorption cell.