Understanding the influence of distillation time on quality and quantity of essential oils in Lemon verbena (Lippia citriodora Kunth) may help methods of this economically important essential oil to improve the production and engineer the constituent of the oils as well as decrease the energy needed for distillation. In this study the effect of distillation time on the content and constituents of the essential oil isolated from Lemon verbena by hydro-distillation method was investigated. Four distillation times such as 1, 1.5, 2 and 3 hours were investigated. The maximum essential oil content (0.73 %) was achieved after 2 hours of distillation, however, the minimum essential oil content (0.57 %) was observed after 1 hour of distillation. The chemical composition of the isolated essential oil was determined by gas chromatography-mass spectrometry (GC-MS). According to the results of GC-MS analysis, 21 major compounds were detected in essential oil. Geranial (29.65 %), neral (23.16 %) and limonene (15.38 %) were the major constituents of analyzed essential oil. The study also revealed that the highest contents of geranial, limonene and neral were obtained at 1 hour distillation time.
