Abstract: The chemical compounds of essential oil from the flowers of Dendranthema morifolium cv. Chuju were studied by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF/MS) combined with supercritical carbon dioxide extraction (SFE). The effects of SFE different parameters including extraction pressure, co-solvent content, extraction time, extraction temperature and CO2 flow rate on the essential oil yield was investigated using orthogonal array design. The results indicate that the optimal extraction conditions are as follow: pressure 35 MPa, co-solvent content 16%, temperature 55 ℃, extraction time 3 h and CO2 flow rate 50 kg/h. Under the optimal extraction conditions, the essential oil yield is 640%. By searching TOF/MS spectral library and comparing the GC×GC retention indices with database values, 92 compounds are identified. The major constituents in the essential oil are terpenoids which make up 6674% of the identified volatile compounds. In addition, three important floral aroma components, 3,4-didehydro-β-ionone, β-Ionon-5,6-epoxide, 3-Hydroxy-5,6-epoxy-β-ionone are rudimentarily found in Dendranthema morifolium.

Key words: supercritical fluid extraction, comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry, Dendranthema morifolium cv. Chuju, essential oil