EMISSION OF LINALOOL FROM VALENCIA ORANGE BLOSSOMS AND ITS OBSERVATION IN AMBIENT AIR

Emission measurements made over a 5-month period of a Valencia orange tree showed the significant emission of the terpenoid linalool (C10H18O) from Valencia orange blossoms. The average annual emission rate of this Olinda Valencia orange, derived from emission measurements which include the blossoming season, is a factor of approximately 10 higher than the average annual emission rate derived from measurements taken outside of the blossom season. Ambient monoterpene and linalool concentrations were measured in Riverside, California, in the spring and supported the chamber plant emissions data, with linalool concentrations as high as 17-mu-g m-3 being observed in an orange grove. These results show that current biogenic emission inventories which are formulated from limited survey data, generally not including seasonal variations in the vegetative emissions, can be subject to large uncertainties.