MWHD used a domestic microwave oven (Kendo,
2.45 GHz, 800 W) with a side orifice through which an external
glass condenser joined a round flask with the plant
material (100 g) and water (1 l), inside the oven. The oven
was operated for 30 min at full power, which caused water
to boil and reflux. Essential oil was decanted from the
condensate. HD was carried out in a similar manner, but
without microwave irradiation, using an electrical heater
(boiling water) for 2 h and after that, decanting the essential
oil from the condensate previously saturated with NaCl. For
GC analysis, 30 l of essential oil were added to 1.0 ml of
dichloromethane and 0.5 l n-tetradecane, used as IS.