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Aromatherapy Articles

Gas Chromatographs-Mass Spectography Reports: A Basic Explanation
aka GC-MS Reports


Joie Power, Ph.D.

Gas Chromatographs (GC) along with Mass Spectography (MS) reports show the relative amounts of the various organic components that make up essential oils. These reports are commonly referred to as GC-MS or GC/MS or GCMS reports. The primary types of components include:

Component Possible Therapeutic Action Possible Toxicity / Skin Irritation
Alcohols Antiseptic, antiviral, bactericidal Low
Aldehydes Antifungal, anti-inflammatory, disinfectant, sedative Moderate
Esters Antifungal, antimicrobial, sedative, antispasmodic Low
Ketones Anticatarrhal, cell proliferate, expectorant, vulnerary High
Lactones Anti-inflammatory, antiphlogistic, expectorant, febrefuge Moderate to High
Oxides Expectorant Moderate
Phenols Antiseptic, bactericidal, disinfectant, stimulant Moderate to High
Terpenes Anti-inflammatory, antiseptic, antiviral, antibacterial,
(some are analgesic or stimulant)
Generally Low

In simple terms, when choosing an essential oil, one wants high therapeutic value and low toxicity. There are many different compounds within each of the major categories - altogether there are several hundred individual chemical substances that are found in essential oils. This makes it difficult to evaluate oils chemically. Even though a chromatograph may show only a few of the constituents of an oil, one still needs knowledge of many individual substances and their properties to read a GC-MS reports.

However, an illustration will show some of the basics: Below are two GC-MS reports - one is for Lavender Provence and one is for Lavender Dalmatian. I prefer the Lavender Provence.
Here is why: A "good" Lavender contains a high proportion of esters and alcohols and a low proportion of camphor. The esters are especially prized in Lavender. "The constituents of different species differ in their content of the ester linalyl acetate due to altitude. If lavender is grown above 2,000 feet, the ester content is increased, producing a more valuable oil." - quoted from the textbook for Aromatherapy Certification of the Australasian College of Herbal Studies.

Both the Provence and Dalmatian Lavenders are high in Linalool - a terpenoid alcohol that is low in toxicity and has good antiviral and antibacterial properties. Both are also low in camphor, which is a ketone and therefore a strong irritant. However even a quick glance at the charts shows that the Lavender from Provence is MUCH higher in Linalyl Acetate, an ester which is very low in toxicity and is highly valued for it's therapeutic effects. It is Linalyl Acetate which gives Lavender its' famous calming properties. Therefore, while either of these lavenders will have good antiviral and antibacterial properties, the Lavender Provence has outstanding calming and antispasmodic properties whereas the Lavender Dalmatian will have a less calming effect.

The Lavender Provence used by Artisan Aromatics costs the company considerably more than the Lavender Dalmatian but we feel that the very superior quality of the Lavender Provence is worth the extra cost.

Lavender Provence (organic)

GC-MS Analysis Report
Peak Area Peak Time Peak Scan Marker Text
1.064 0:16:06 357 Pinene or Beta-Myrcene
7.432 0:17:04 414 Ecalyptol; 1:8 Cineole
31.909 0:18:07 475 Linalool
7.518 0:19:07 534 Camphor
3.282 0:19:35 561 Borneol
5.317 0:19:43 569 CAS 562-74-3
27.504 0:20:46 630 Linalyl Acetate
3.585 0:21:14 657 Geraniol Acetate
1.362 0:23:58 817 Farnesene
1.085 0:24:01 820 Caryophylene

Instrument: VG70E
Notes: MS/LB CB5 50m 1.2u 40(5)>250@10 10m/m spli 10psi inj 220 - 1.2x10-6 - 10mg in 1ml DCM 1ul inj Gas Chromatograph / GC Graph - Lavender Provence (organic)

Lavender Dalmation

GC-MS Analysis Report
Peak Area Peak Time Peak Scan Marker Text
0.571 0:15:57 578 a-Pinene
3.404 0:17:40 678 Ocimene Isomer
0.732 0:17:50 688 d-Limonene
7.369 0:17:54 692 Eucalyptol
40.241 0:18:52 748 Linalool
1.952 0:20:03 817 Camphor
1.453 0:20:21 834 Hexyl Butanoate
7.234 0:20:32 845 endo-Borneol
7.084 0:20:38 850 Terpinen-4-ol
6.281 0:21:31 902 Linalyl Acetate
0.850 0:22:00 930 Lavandulyl Acetate
2.713 0:24:47 1091 b-Farnesene

Instrument: VG70E
Notes: MS/LB CB5 50m 1.2u 40(4)>250@10 30m/m spli 15psi inj 250 - 1.2x10-6 16.3mg Gas Chromatograph / GC Graph - Lavender Dalmatian

*This information is provided for educational interest and is not intended to diagnose, treat, or cure any disease.

Copyright © 2010 Joie Power, Ph.D. / The Aromatherapy School  |  All Rights Reserved

This article under the title, "Gas Chromatography: A Simple Explanation" was originally published for Dreaming Earth Botanicals, LLC

Dr. Power is a retired board certified neuropsychologist and former Assistant Professor of Surgery/Neurosurgery at the Medical College of Georgia, where she performed intra-operative cortical mapping with renowned neurosurgeon Herman Flanigan, M.D. She has over 20 years of clinical experience in both in-patient and out-patient settings and during her years of practice has also been both a practitioner and student of alternative healing methods, including herbal medicine, aromatherapy, Reiki, Chinese Medicine, and other energetic healing systems. Her extensive formal training and experience in the olfactory and limbic systems of the brain give her a unique qualification for understanding the actions of essential oils in the body. Dr. Power, founder of one of the earliest essential oil companies in the U.S. to specialize in therapeutic quality essential oils, is now a clinical consultant for Artisan Aromatics as well as an internationally known writer and teacher in the fields of aromatherapy and alternative medicine. Her approach to aromatherapy weaves together her solid scientific training and strong clinical skills with a holistic philosophy that honors body, mind and spirit. Dr. Joie Power is also the author of The Quick Study Guide to Aromatherapy and numerous published articles on aromatherapy and related topics.

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