Abstract
Rose oil is traditionally produced by the water distillation of Rosa damascena and is of high economic value due to the low essential oil yield. It is therefore a common target for adulteration, which can cause harm to consumers. Current standards for authenticity control only consider the analysis of major components and overlook minor quality markers as well as the enantiomeric ratio of terpenes, which have proven useful in originality determination. The aim of this study was the development of two analytical GC-FID methods for the analysis of 21 and 29 rose oil analytes including major, minor and chiral components on a DB-wax and BGB 178 30% CD (chiral) capillary column, respectively. The total run time for both methods was within 60 min. For all target analytes, the % bias at the lower and upper calibration range varied from -7.8 to 13.2% and -13.1 to 5.2% analysed on the DB-wax column and 0.5 to 13.3% and -6.9 to 7.0% analysed on the chiral column. The chiral analysis successfully separated the enantiomers (+/-)-camphene, (+/-)-rose oxide, (+/-)-linalool, (+/-)-citronellol and (+/-)-citronellyl acetate, as well as the diastereomers of citral and β-damascenone. Both methods were applied to the analysis of 10 authentic rose oil samples and the enantiomeric/diastereomeric ratios, as well as the content of major and minor components, were determined. The identity of the analysed components in the authentic samples was further confirmed by GC-MS.