Quantification of carvone, cineole, perillaldehyde, perillyl alcohol and sobrerol by isocratic high-performance liquid chromatography.

A simple and rapid isocratic HPLC assay is presented for the analysis and quantification of monoterpenes, i.e., carvone, cineole, perillaldehyde, perillyl alcohol and sobrerol in the diet of laboratory animals. The monoterpenes were extracted from the diet using 90% methanol in water. The analysis for the monoterpenes was performed by HPLC using a Whatman PartiSphere C18 column with UV detection. The mobile phase was isocratic methanol-water (72:28, v/v) for carvone, cineole, perillaldehyde and perillyl alcohol and methanol-water (65:35, v/v) for sobrerol. The method was simple with good repeatability (R.S.D. = 4.2-16.1%), reproducibility (R.S.D. = 3.7-19%), and accuracy (R.S.D. = 5.5-23.3%). The detection limit of the monoterpenes extracted from the diet was 2 micrograms/g for carvone, perillaldehyde and sobrerol, 20 micrograms/g for perillyl alcohol and 100 micrograms/g for cineole. Excellent resolution was achieved between the monoterpenes and the constituents of the diet. The method demonstrated applicability to monitoring the formulation of monoterpenes in the diet of laboratory animals.