A NEW METHOD FOR AUTHENTICITY CONTROL OF LEMON OILS BY HPLC

For the control of the correctness of lemon oils essentially photometr ic methods are used. They are based on the absorbance of the coumarins and psoralens in the oils. For adulteration purposes substances with absorbance properties similar to those of the naturally occurring ones can be added, thus pretending a higher concentration and quality. - T he presented HPLC method offers new possibilities for an easy, quick a nd precise characterization of lemon oils. Adulteration with ethyl p-d imethylaminobenzoate and menthyl anthranilate can be proved without pr oblems. The detection limit is so low that an adulteration of this kin d is no longer attractive. When the usual photometric determination of the so-called CD value is applied for quality control, largely higher amounts must be added to give a delusive effect. In addition to this, the method allows statements on the provenance of the oil. In the cas e of concentrated oils the real degree of concentration can be checked .