4. Conclusion
It is evident that sandalwood oil composition may vary
depending on its geographical and taxonomic origin, which
may reflect current international demand and declining resources.
It should also be noted that santalol composition
can vary depending on the method of oil extraction [23].
From the present study, it is apparent that generally accepted
specifications (90% santalol content) and analysis
methods require re-evaluation. Thus, it is suggested that
quality control and authentication procedures for sandalwood
oils should not rely on old methods of analysis (calculation
of the total santalol/alcohol content) and that GC–MS
is recommended.
In conclusion, a specification of ≥43% Z--santalol and
≥18% Z--santalol by GC–MS for S. album oil is suggested,
based on S. album samples analysed in this study.
These suggested specifications support those described by
the ISO (2002) for GC-FID analysis of S. album; in addition,
GC–MS has the advantage of assisting with the detection and
identification of adulterants. ‘Sandalwood’ oils with santalol
levels below these specifications may be of inferior quality
due to extraction from undeveloped heartwood, adulteration
(e.g. with synthetic or semi-synthetic substitutes) or substitution
with oils from other species. GC–MS profiles may
provide information regarding the species of origin; for example,
preliminary investigations in this study suggest that
312 M.-J.R. Howes et al. / J. Chromatogr. A 1028 (2004) 307–312
oils comprised of 16–22% and 6–8% Z-- and Z--santalol,
respectively, are likely to have originated from S. spicatum
and not S. album.