In the world of clinical aromatherapy, the quality and purity of essential oils are paramount. Although oils may share the same name—for example, Lavandula angustifolia (narrow-leaved lavender)—their chemical composition can vary significantly depending on the growing location, climatic conditions, distillation method, and storage. These differences affect not only the fragrance but, above all, their therapeutic properties and safety.

The only reliable way to assess the quality and chemical composition of essential oils is analysis by gas chromatography coupled to mass spectrometry (GC-MS).

What is GC-MS analysis?

GC-MS (Gas Chromatography – Mass Spectrometry) is an advanced analytical technique that allows for the identification and quantification of chemical compounds in a given essential oil. In practice, GC-MS analysis provides a detailed chemical fingerprint of the oil, allowing us to precisely determine its composition, purity, and authenticity.

Gas chromatography (GC) – separates the components of an essential oil into individual chemical compounds.

Mass spectrometry (MS) – identifies these compounds, creating their precise profile.

Why is GC-MS analysis important?

Ensuring purity and authenticity

GC-MS analysis can detect adulteration of essential oils, such as the addition of synthetic substances or dilution with cheaper oils. For example, chamomile oil (Chamomilla recutita) is often adulterated with the addition of synthetic azulene or bisabolol, which alters its effectiveness.

Chemical composition and safety assessment

Different batches of the same oil can have completely different chemical compositions. Lavender oil grown in France contains high concentrations of linalyl acetate and linalool, which gives it soothing and relaxing properties. Lavender from Australia, on the other hand, may contain more camphor, making it more stimulating and less safe for children.

Therapeutic selection

In clinical aromatherapy, matching the oil to the patient's needs is crucial. GC-MS analysis ensures the oil has the appropriate concentration of active ingredients. An example is thyme oil (Thymus vulgaris), which comes in various chemotypes:

• Thymus vulgaris ct. thymol – strongly antibacterial, but irritating to the skin.
• Thymus vulgaris ct. linalool – milder, suitable for children and people with sensitive skin.
  

Examples of chemical differences in essential oils

Eucalyptus oil

Eucalyptus (Eucalyptus) can be obtained from various species:
Eucalyptus globulus – contains about 70–85% eucalyptol, has a strong expectorant and antibacterial effect.
Eucalyptus radiata – more gentle, more suitable for children's therapy.

Peppermint oil (Mentha piperita)

The chemical composition of peppermint oil may vary depending on the region and harvest time:
The high concentration of menthol gives the oil a cooling and analgesic effect.
Too much menthone may cause irritation and is not recommended for pregnant women.

Lemon oil (Citrus limon)

Oil pressed from lemon peels contains limonene (60–70%), which has refreshing and antibacterial properties. Without proper analysis, you may encounter oil contaminated with pesticides or with a significantly lower concentration of active ingredients.

No analysis = health risk and no therapeutic effects

Choosing an oil without GC-MS analysis is a risky gamble. At best, it won't deliver the expected results; at worst, it can cause irritation, allergies, or even poisoning. We emphasize the importance of certified oils with tested chemical compositions.

Good practices when purchasing essential oils

1. Choose oils with GC-MS certification. Ask the seller for analysis results for a given batch of oil.
2. Avoid products with suspiciously low prices. Rose oil for 50 PLN? It's definitely not pure Rosa damascena, but an adulterated product.
3. Pay attention to the place of origin. Growing conditions have a huge impact on the chemical composition of the oil. Lavender from Bulgaria differs from that from Provence, France, or Greece, both in terms of its key constituents and its therapeutic effects.

GC-MS analysis as a guarantee of quality and safety

GC-MS analysis is a key tool in assessing the quality of essential oils, especially in the context of their therapeutic applications. It ensures we're using a product with the correct composition, free from contaminants and synthetic additives. By choosing GC-MS-certified oils, you're investing in your health and safety, as well as the effectiveness of your therapy.

Comparison with Bulgarian, French and Greek lavender

Characteristic	Bulgarian lavender	French lavender	Greek lavender
Linalyl acetate	28.64%	35–45%	31.82%
Linalool	28.78%	20–25%	31.82%
Camphor	0.25%	0.1–0.2%	0.29%

• French Lavender: The highest concentration of linalyl acetate (40%), enhancing its relaxing effects. Its very low camphor content (0.15%) makes it ideal for gentle aromatherapy applications.
• Bulgarian Lavender: Balanced chemical profile, high in linalool (28.78%), which supports antibacterial and skin-regenerating properties. Camphor (0.25%) adds a slightly stimulating note.
• Greek Lavender: Exceptionally high levels of linalyl acetate (31.82%) provide a powerful relaxing effect. Its chemical profile is mild, and camphor (0.29%) remains within safe skin limits.

Graph comparing the content of cis-beta-ocimene , terpinen-4-ol and beta-caryophyllene in lavender oils from France , Bulgaria and Greece :

• Cis-Beta-Ocimene: The highest concentration in Greek lavender (6.47%), which enhances its antibacterial and anti-inflammatory properties.
• Terpinen-4-ol: Very similar values in Bulgarian lavender (5.49%) and Greek lavender (5.05%), indicating their strong immunomodulatory and anti-inflammatory effects. French lavender has a lower content of this nutrient, making it more gentle on the skin.
• Beta-Caryophyllene: Bulgarian lavender (4.61%) has a higher concentration, which gives it analgesic and anti-inflammatory properties, ideal for dermatological applications.

1. Differences in key chemical components

• French Lavender – This oil has an exceptionally high linalyl acetate content (35–45%) and a low camphor content (0.1–0.2%). This makes it ideal for deep relaxation, stress reduction, and as an ingredient in cosmetics for children and those with sensitive skin.
  Additional ingredients such as cis-beta-ocimene (4%) and beta-caryophyllene (2.5%) are present at moderate levels, resulting in a balanced therapeutic effect.
• Bulgarian Lavender – A more balanced chemical profile, with 28.64% linalyl acetate and 28.78% linalool , making it versatile. Its high terpinen-4-ol (5.49%) and beta-caryophyllene (4.61%) content enhances its anti-inflammatory, skin- and immune-supporting properties. It also has a more intense fragrance thanks to 5.09% cis-beta-ocimene .
• Greek Lavender – The highest concentration of cis-beta-ocimene (6.47%) makes this oil highly antiseptic and has a refreshing aroma. Linalool (29.27%) and linalyl acetate (31.82%) provide a relaxing effect similar to French lavender, but the additional note of terpinen-4-ol (5.05%) makes it a bit more versatile.

2. Therapeutic application in practice

French Lavender: Ideal for sleep therapy, anxiety relief, and sensitive skin care. Especially recommended for children and the elderly.

Bulgarian Lavender: Versatile – suitable for relaxation, immune support, and problem skin therapy. Excellent for use in massage and natural cosmetics.

Greek Lavender: Excellent for inhalation and respiratory support, thanks to its high concentration of cis-beta-ocimene . It also works well as a flavoring ingredient in essential oil blends.

3. How to make an informed choice?

Looking for delicacy and luxury? Choose French lavender .

Need a more intense therapeutic effect? – Choose Bulgarian lavender .

Interested in combining relaxation with additional support for the respiratory system? Try Greek lavender .