In short
An analytical dossier gathers what is reliably known about one natural material from published and supplier data, including its identity, typical composition, markers, methods, sensory links and gaps. It's a desk project, and you need no instrument. What it shows is that you can read analytical evidence critically, which is exactly what a perfumer, buyer or client needs from this track.
What you will learn
- Build an evidence-based dossier on one natural material
- Compare sources critically, including their methods
- State what the data cannot show
Before this lesson: Headspace Sampling Methods Compared
What to choose
Pick a material with enough published work to compare, and that you can also smell. Lavender, bergamot, vetiver and patchouli are candidates. Choose an unusual one only if you can find a few independent analyses.
Dossier structure
| Section | What it contains |
|---|---|
| 1. Identity | Species, part, process, CAS numbers, any ISO standard, and known chemotypes |
| 2. Composition table | Main constituents across at least three sources, with ranges, origin and method |
| 3. Method comparison | What each source used: column, detector, normalization |
| 4. Identification notes | Coelutions and difficult compounds; retention index check on at least five |
| 5. Trace odorants | What GC-O or sensory work reports, with limits |
| 6. Authenticity | Markers, chiral data and common adulterants as reported; what each can show |
| 7. Regulatory links | Known restricted or declarable constituents, dated. Marked "for confirmation" |
| 8. Your own evaluation | Your sample's details and what you smelled, kept separate from the literature |
| 9. What remains unknown | Specific gaps, and which test could close each one |
Standards of evidence
- Cite each source in full, so someone else could find it. Do not cite a paper you haven't read, except by marking it "cited in".
- Prefer peer-reviewed analyses and formal standards for composition. Label supplier data as such.
- Don't merge figures across incomparable methods as if they were one range.
- Round to what the source supports, and keep its units.
- Record the date you accessed each source.
An example of careful wording
Invented example: Three published analyses of Bulgarian samples report compound X at about 30%, 34% and 38% by normalized FID area on low-polarity columns. One Provençal analysis reports 25% on a wax column by MS. We can't separate the effects of origin and method from these four. We have no authenticated sample.
Such a sentence is much more use than a single figure. It shows what's known and how well.
The sensory bridge
For section 8, smell a sample you can identify by lot, in dilution, over a time course. Note which reported constituents you believe you can perceive, and mark it as an impression. Ideally, compare it with two or three reference materials from your organ, such as linalool and linalyl acetate for lavender. You're looking for relationships to test. You aren't proving anything.
Practical and ethical limits
Write nothing that amounts to an accusation about a named supplier. Respect copyright: summarize the data with citations, and don't reproduce a paid standard. If your dossier goes beyond what you can verify, say so. It should not be presented as a certificate of analysis or a safety document, because it is neither.
Assessment
| Criterion | Meets it if |
|---|---|
| Sources | At least three independent analyses, cited in full, with methods stated |
| Comparison | Differences are discussed, and not simply averaged |
| Identification | Five compounds have retention index checks, with phase noted |
| Quantification | Each figure says whether it's area or calibrated weight |
| Separation | Literature, supplier data and your own observations are kept apart |
| Honesty | The gaps section is real and specific |
Practical exercise: Final project: an analytical dossier
Complete the dossier described above, at up to eight pages. Allow two weeks, and ask someone to read it with two questions in mind: what do they doubt, and what can't they find?
You have done this well if a reader with analytical experience could check your citations, and would agree with your statement of what the data can't show. Completing this track is not a qualification in analytical chemistry.
Common mistakes
- Writing a summary of one review. Compare primary analyses.
- Dropping method details. Numbers mean little without them.
- Letting the literature describe your bottle. Your lot is its own sample.
Knowledge check
Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.