Evaluation of the quality of sandalwood essential oils by gas chromatography–mass spectrometry

Trade and historic oils from ‘sandalwoods’, labelled as Amyris balsamifera, Eremophila mitchelli, Fusanus acuminatus (= Santalum acuminatum), Santalum album, S. austrocaledonicum, S. latifolium, S. spicatum and S. yasi, were assessed using gas chromatography–mass spectrometry (GC–MS). Using GC–MS, none of the oils assessed complied with the internationally recognised standard of a 90% santalol content, and only about half of the trade sandalwood oils met with recent International Organisation for Standardisation standards. The majority of trade oils, reportedly from S. album, contained approximately 50–70% santalols (Z-α and Z-β). Thus, the internationally recognised specification (90% santalols) for S. album requires re-evaluation by more efficient analysis methods. In view of the issues associated with the quality of sandalwood oils being traded, specifications of ≥43% Z-α-santalol and ≥18% Z-β-santalol for S. album oil estimated by GC–MS are suggested. GC–MS are recommended as it assists with authentication and quality control issues associated with sandalwood oils.