Hello, may I ask some help for better understand the "90-92% santalol" issue? Should we forget forever about this 90%? I read some scientific articles and found that both vintage and modern sandalwood oils do not contain 90% santalols at all. Just never. Because 90% santalols related to the total free alcohols content in oil and it is not (alfa-santalol + beta-santalol). Moreover 90% santalols is an ancient standard (oil evaluated using ancient acetylation method which not specific for santalols and may give large errors that increase total santalols to 90%). Modern standard ISO (2002) states that sandalwood oil should contain 41-55% alfa-santalol and 16-24% beta-santalol (GC method for evaluation). According to one research by Verghese, 1990 year when evaluating commercial sandalwood oil in 24 samples from 1990 year with GC method they revealed that all samples contain total alfa + beta santalols 61% - 71%. For example very famous Fritzsche sandalwood oil contain 60% santalols (alfa+beta, GC method). In the new research by Howes, 2004 year, it was determined that in 31 samples of commercial sadalwood oil, approximately 50-70% alfa+beta santalols (GC method). Authors of research conclude that only GC method show real picture and quality of sandalwood oil. And the ancient "90% minimum total alcohols as santalol" should go away in the past.
In conclusion I want to say, that even good sandalwood oils from 1990 never had any 90% santalols in fact.
I am a researcher, a biologist, so I wrote this post to ask the opinion of more experienced people. Most people probably think that sandalwood oil should contain 90% santalols, but this is apparently not entirely true. People are just used to this figure of 90% and consider it a sign of quality. Indeed, earlier, to determine the content of santalols, the old acetylation method was used, which was not specific and did not show a real picture. The modern gas chromatography method more accurately determines the content of santalols, and even in best oils santalols usually do not exceed 70% (and if in the same oils santalols were determined by the old method, they would be more than 90%, I believe). If I'm wrong please correct me, I'm just trying to find the truth.