How to Read a GC/MS Report
A GC/MS (Gas Chromatography / Mass Spectrometry) report is the single most important document when sourcing essential oils. It tells you exactly what's in the bottle — molecule by molecule. Here's how to read one.
The Three Sections of a GC/MS Report 1. Chromatogram — a graph with peaks. Each peak = a molecule. Bigger peak = more of it. 2. Identification table — names each peak (e.g., 'linalool'), shows its percentage. 3. Total area % — the percentage breakdown of the entire oil composition.
What to Check 1. Is the dominant molecule correct? Each oil has a fingerprint: - *Rose otto*: citronellol (25–40%), geraniol (10–20%) - *Lavender*: linalool (30–40%), linalyl acetate (30–45%) - *Sandalwood*: alpha + beta santalol (>40% combined) - *Jasmine sambac*: benzyl acetate (15–25%), linalool, indole
If the markers are off, the oil is either from a different species or has been adulterated.
2. Are 'suspect peaks' present? Some molecules signal adulteration: - *Diethyl phthalate (DEP)* in a 'natural' oil → fragrance dilution - *Synthetic linalool* added to lavender → look for unusual chiral ratios - *Methyl anthranilate* high in jasmine? Possibly added
3. Chiral GC For premium oils (rose, lavender, sandalwood), a chiral GC distinguishes natural enantiomers from synthetic ones. Natural materials have specific chiral ratios; lab-synthesized molecules are typically racemic.
Red Flags - A GC/MS report missing percentages - A report with peaks 'unidentified' and no follow-up - A report that looks like a generic template (same date for multiple batches) - Refusal to provide a GC/MS at all
What We Provide Every batch of every product at House of Absolutes KA ships with: - Third-party GC/MS profile with full peak identification - Certificate of Analysis (COA) - MSDS (Material Safety Data Sheet) - IFRA certificate (where applicable)
Need Help Interpreting a Report? If you've bought oils elsewhere and aren't sure if the GC/MS checks out, send it to us — we'll review it free of charge for B2B buyers.
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