Influence of extraction method and storage conditions on the volatile oil of wormwood (Artemisia absinthium L.)

In order to determine the best extraction procedure for volatile oil composition studies in wormwood (Artemisia absinthium L.), several extraction techniques have been investigated. In pentane extracts obtained using microwave or ultrasound sources of radiation, no thermic degradations occurred, but high amounts of heavy oils and waxes resulted, causing trouble in the gas chromatographic analysis. Headspace extraction provided the most volatile constituents, but high molecular weight compounds were not extracted. Simultaneous distillation-extraction resulted in the most adequate extraction procedure for volatile oil composition studies since the required compounds were extracted with minimum degradations when the distillation time was no longer than 30 min. Freezing and drying processes did not greatly affect the percentage composition of wormwood volatile oil.