How to Read a Clary Sage GC/MS Report, Peak by Peak

A GC/MS report is a list of peaks and percentages, and the percentages are shares of each other, not amounts. That one fact decides how much a clean-looking report can prove. Below is the order we would read a clary sage report in, with the numbers to hold it against, and what to do with the Certificate of Analysis on our Purity oil page.

Clary Sage Essential Oil bottle

Clary Sage Essential Oil

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Start with an arithmetic trap

Take an invented oil, normalised to 100 parts: 60 parts linalyl acetate, 18 parts linalool, 22 parts everything else. Now stir in 10 parts of linalyl acetate that came from a drum rather than a plant. The total is 110 parts. Linalyl acetate is now 70/110 = 63.6% and linalool is 18/110 = 16.4%. Both figures sit inside the ranges that a regulator found for real clary sage oil (see below). A report that only lists those two percentages looks normal for the adulterated oil and for the honest one. This is reasoning from the arithmetic, not a measurement of any real oil, but it is why the rest of this page exists.

What the letters mean

GC separates an oil into its components as they travel through a long capillary column. A detector then records each peak. With a flame ionisation detector (GC-FID) the area under a peak is the quantity; with a mass spectrometer (GC-MS) you also get a fragment fingerprint that helps name the peak. Labs commonly run both: MS to name, FID to count. The EFSA feed-additive opinion on clary sage oil followed that pattern, with EFSA FEEDAP Panel, EFSA Journal, 2024 reporting a GC-FID specification table from three batches and a fuller GC-MS table from six batches, with up to 84 peaks per batch and identified compounds averaging 98.9% of the area.

Two details to look for. First, a name is only as good as its retention index, a column-independent number that places a peak relative to a ladder of alkanes. The general capillary GC method, ISO 7609:1985, describes naming constituents by retention index and quantifying by peak area. (ISO 7609 is the method, not a clary sage specification; ISO's catalogue lists it as published in 1985, confirmed in 2020 and flagged in September 2025 for revision.) Second, we would want a report to state the column and how peaks were named.

The numbers to hold it against

The clary sage oil specification we could verify is the one EFSA wrote for a feed additive, made by steam distillation of flowering stems with plant material sourced from France or Russia. It is not a standard for aromatherapy or perfumery, and its three-batch sample is small. Within those limits:

ConstituentEFSA specification (GC-FID)Three batches, GC-FIDSix batches, GC-MS
Linalyl acetate55 to 78%61.87 to 74.84%51.71 to 64.22%
Linalool6.5 to 25%10.88 to 17.91%13.46 to 20.68%
Germacrene-type triene1 to 12%3.57 to 4.50%2.21 to 6.46%
Alpha-terpineol0 to 5%0.55 to 2.64%0.87 to 3.85%

Read that table twice, because it contains a lesson. The three FID batches and the six MS batches are different batches, so the table does not isolate the method, but the linalyl acetate range sits about ten points lower in the MS column (51.71 to 64.22% against 61.87 to 74.84%). Reasoning from that, a report that gives 58% and one that gives 68% may not be in conflict, because batch, detector and integration all move the figure. Compare like with like where you can: FID figure to FID figure.

Real oils also vary with the plant. A 2013 paper on Bulgarian oil identified 52 compounds with linalyl acetate at 56.88%, linalool at 20.75% and germacrene D at 5.08% (Hristova et al., J. BioSci. Biotechnol., 2013). Two Lebanese sites sampled in the same week gave a linalool-rich oil (average 40.2%) and a linalyl acetate-rich oil (average 50.4%) (Raafat and Habib, J. Oleo Sci., 2018). So a linalool figure far above the usual range is not automatically fraud, and a linalyl acetate figure in range is not automatically honest. The origin question has its own post: our origin comparison.

Sclareol: the number people misread

Sclareol is a heavy diterpene, and it is where sources disagree most. EFSA's six batches averaged 0.51% (0.32 to 1.18%). Robert Tisserand wrote in 2010 that gas chromatography typically finds 0.1 to 0.4%, that an older French text gave 1.6 to 7.0%, and that low volatility may make GC understate it (Tisserand, 2010). Treat a sclareol line as method-dependent and do not read much into 0.3 versus 1.0.

Chiral analysis, and what it can and cannot do

Linalool and linalyl acetate each exist as mirror-image forms. A chiral column separates them, and the ratio between the two forms in an authentic oil can differ from the ratio in an added synthetic ingredient, which makes it one more piece of evidence. A review in the Journal of Natural Products notes that chiral columns, multidimensional GC, isotope ratios and carbon-14 can detect some adulteration, that adulterants are often added at levels that are profitable yet hard to detect, and that undeclared synthetic compounds can go unnoticed if only a few compounds are analysed. It gives lavender oil spiked with linalool and linalyl acetate as an example, and recommends combining several methods (Gafner et al., J. Nat. Prod., 2023). That paper does not give reference ratios for clary sage, and we did not find any we could verify, so we cannot tell you what a clary sage chiral result should be.

What no report can show

Applying this to our two oils

We do not publish an annotated report and we are not going to describe what is in a document on a page you can open yourself. The Purity oil, sold as Salvia sclarea, has a Certificate of Analysis on its product page. Check, in order: that the species is named; that a lot reference exists and can be matched to the bottle; that the method (column, detector, retention indices) is stated; that the main constituents are in a plausible range, comparing FID to FID; and whether a chiral or other authenticity test is mentioned. The Botanical oil is sold as botanical grade and its page does not name the species. Its page offers lot details on request, and that is the document to ask for if identity matters to you. See also our pre-purchase checks and the linalyl acetate chemistry post, and read what grade words do and do not mean.

A good report earns trust in a lot; it does not replace your own nose and a patch test. We sell the oils undiluted and our pages advise 0.5% to 2% in a carrier oil, so the dilution is yours to calculate.

Clary Sage Essential Oil bottle

Clary Sage Essential Oil

Clary Sage Essential Oil from our own shop, in sizes from 0.5 oz to bulk.

From $19.99

Shop Now →

Sources & Further Reading