Spinning cone column isolation of rosemary essential oil

Chemical compositions of rosemary (Rosmarinus officinalis L.) essential oil isolated using different processes, steam distillation and a spinning cone column (SCC), and harvested at different times, spring and autumn, were compared. The effect SCC operating parameters had on yields was also studied. The method used for isolating the oil influenced its composition and yield. The main components found were: camphor, β-myrcene and 1,8-cineole. SCC derived oils were more consistent and richer, on average, in oxygenated compounds than steam distilled oils. Furthermore, citronellol, chrysanthenone, piperitone and thymol were detected in SCC oils but not in their steam distilled counterparts. SCC yields were more consistent at a 1/40 dilution while higher yields were achieved at the same dilution spinning at 570 rpm.