Even when products are sold under the same name, “lavender oil,” the contents of their bottles may not be identical. Some differences arise from where and how plants grow or from extraction methods; others may reflect ingredients added during product formulation. How far can chemical analysis investigate these differences?
A study published by Abouelela and colleagues in 2026 compared four commercial lavender oil products from the Egyptian market. Combining component measurements with statistical analysis of differences across many components, the researchers sought clues for assessing quality and authenticity.
- Analyzing four products under the same conditions
- The figures are not exact weight percentages in the bottle
- Major aroma components varied widely
- Unusual components provide clues for further investigation
- Distinguishing combinations of components statistically
- Extraction methods cannot be ignored
- Summary
- References
Analyzing four products under the same conditions
The researchers purchased products from four companies in Cairo in September 2024. Three independent samples of each were measured using the same preparation procedure and instrument conditions. This was a comparison of four products, not 12 different products or a large survey representative of the entire market.
According to their labels, two products were steam-distilled and the other two were solvent-extracted. Detailed information about the plants’ geographic origins, cultivation conditions, and factory extraction conditions was not disclosed, so the causes of the differences cannot be fully separated.
The analysis used gas chromatography–mass spectrometry, or GC–MS. This separates and detects components, then compares the signals with existing databases and other information to investigate possible identities. Because liquid samples were injected directly in this study, the analysis included relatively less volatile components as well as readily volatile aroma compounds.
The figures are not exact weight percentages in the bottle
The study expressed the signal area for each detected component as a proportion of the total. No internal standard or correction for compound-specific detector response was used, so the results are semiquantitative relative values.
For example, reporting a component at “about 16%” does not establish precisely that it makes up 16% of the weight of the bottle’s contents. The figures should be read as clues for comparing the compositions of products measured under the same conditions.
Detecting more of a component is also not synonymous with a stronger fragrance or higher quality. The study did not measure perceived pleasantness or product efficacy.
Major aroma components varied widely
The study reported 54 components. Particular attention was given to linalool and linalyl acetate, which are important when assessing the characteristics of lavender oil.
The relative values in the table ranged from about 10.9–33.6% for linalool and about 11.0–46.1% for linalyl acetate across the four products. These two components were relatively abundant in the two products labeled as distilled, which the authors judged to be closer to the known composition of Lavandula angustifolia oil.
However, similar proportions of these two components do not establish that every quality criterion has been met. Botanical species and origin, other constituents, and physical properties also need consideration. Simply adding major components to bring the figures closer does not necessarily produce the same material as the original plant oil.
Unusual components provide clues for further investigation
One product labeled as solvent-extracted was reported to contain about 16.2% 2,4-pentanediol. The authors regarded this as atypical of ordinary lavender essential oil and suggested that formulation solvents or additives might be involved.
In the other, fatty acids and their esters accounted for relatively large proportions. Components assigned as isopropyl linoleate and oleyl acetate, among others, led the authors to discuss possible dilution or formulation with carrier oils or cosmetic ingredients.
In other words, the analysis identified compositions that are difficult to explain through natural variation alone. However, compound identification relied on database matching and related methods; not every compound was verified with an authentic standard. Without manufacturing records and additional analyses, it is not possible to determine who deliberately adulterated a product, or when.
Adding other ingredients is also a separate issue from whether the resulting product may be labeled as a pure essential oil. This study did not assess the safety of individual products or legally determine labeling violations.
Distinguishing combinations of components statistically
The researchers compared overall patterns as well as individual components. Principal component analysis summarizes differences across many components along a small number of axes. Placing samples with similar compositions close together and those with different compositions farther apart makes product-specific characteristics easier to see.
In this analysis, samples from the product with prominent glycol components tended to separate from the other products. Another analysis, which used predefined product groups for comparison, also identified linalool, linalyl acetate, and aliphatic components among the features contributing to discrimination.
Separation in a statistical plot is not itself a finding of fraud. It is a way of organizing differences in the measured products’ chemical compositions. Nor can the ease of distinguishing this small set of products be treated as an accuracy rate guaranteeing detection of adulteration in unfamiliar products.
Extraction methods cannot be ignored
Steam distillation and solvent extraction preferentially recover different components. Solvents may also extract less volatile lipids, so it would be inappropriate to explain every difference between products made by different extraction methods as dilution or adulteration.
The authors acknowledge this difference and the lack of raw-material information as limitations. Even so, they consider high proportions of particular components a sign that the product-making process needs investigation alongside ordinary variation of plant origin.
They propose expanding the range of samples and combining the analyses with physical measures such as density and refractive index. Bringing together chemical fingerprints, information about raw materials and processing, and physical properties can support more reliable quality assessment.
Summary
The four products purchased in Cairo showed substantial compositional differences, from the proportions of major constituents to components not usually prominent in lavender essential oil. GC–MS and statistical analysis helped visualize those differences and narrow down the products and components needing further investigation.
The study’s significance lies in outlining a way to assess contents that cannot be understood from a fragrance impression or product name alone, using multiple lines of evidence. The authors conclude that incorporating such analyses into routine quality control is needed to support product consistency and consumer confidence.
References
Abouelela, M. B., El-Taher, E. M., Shawky, E. M., & Baky, M. H. (2026). Uncovering adulteration and quality variations in commercial lavender essential oils from the Egyptian market using GC–MS and chemometrics. Scientific Reports, 16, 12735. DOI: 10.1038/s41598-026-45972-6 / Full text. Original article: © The Author(s) 2026, CC BY 4.0.
