Abstract
A reliable method for the extraction and determinatin of bergapten was established. When hydrophobic bergapten was treated with alkali, it became soluble in water through unfolding of its lactone ring. Hydrophobic substances were removed by washing with ether, then it was subjected to the closing reaction of lactone ring by heating with 10% sulfuric acid and the revival bergapten was extracted with chloroform. An aliquot of the solvent layer was injected into an FID gas chromatograph fitted with 5% SE-30 column and subjected to the determination by use of chrysene as an internal standard. A good linearity of calibration curve was obtained within 5-500μg/ml of bergapten, variation coefficient at 33.3μg/ml level being 4.6%. Recovery of 92.6% was obtained at the spike level of 100μg/g of bergapten into bergamot oil. The maximal bergapten content in seven commercial bergamot oils was as high as 1, 000ppm.
