Chemical components of eucalyptus EO

So, I said I would do it and I did! I took 2 types of eucalyptus oil, GC/MS'ed them at work (on my last night on the night shift) and compared the resulting compounds.

A brief overview of a GC MS.

A GC is a gas chromatograph. It takes a volatile compound, turns it to vapor, sends it into a column to be separated into its components, and passes onto a detector. Components are separated mostly by boiling point of the various compounds because the temperature ramps up as the time goes on (for my application). The column is very thin and made of silica [essentially glass]) that is about 90 feet long (it is wrapped into a coil). The internal diameter is less than 1 millimeter.
The system is hooked up to a detector that detects different compounds as little peaks. The combination of all peaks in one sample is called a chromatogram.

The MS (mass spectrometer) allows one to identify these peaks because it is an additional detector that breaks apart the molecules into smaller parts and creates a "fingerprint" for each peak. Each of these finger prints is compared to an existing library to find matching compounds.

I used now foods eucalyptus EO and a cheap eucalyptus EO made by a company called sanvall that I thought might have been adulterd (even though it smelled great it was just very cheap, $1.97 for a 1 oz bottle)

I can post the chromatograms for those that are interested in later comments but for now I will just list the identifiable (no less than 0.01%) components in each.

NOW foods:
In order of elution in the chromatogram:
- alpha phellandrene
- R-alpha- pinene
- sulcatone
- camphene
- beta pinene
- alpha phellandrene
- terpinolene
- *D- limonene/ Eucalyptol major component
- Y-terpene


Sanvall
-alpha thujene
- alpha pinene
- camphene
- beta myrcene
- beta pinene
- cymene (p-cymene)
- *Eucalyptol/d limonene (Major component)
- y terpene
- linalool

*Eucalyptol/D-limonene came out as one peak although I was able to see them separated enough to identify both of them.

I actually like the way the sanvall smells better. It has more citrus and minty top notes (this is due to the greater amount of pinene/thujene)

I was surprised as how different the 2 eos were even though they were the "same". I could've run on a longer column to resolve (separate) the d limonene and Eucalyptol but I didn't feel like it!


ETA:
Ok, later today I'm going to post about each of those compounds and what they are/where they are most commonly found.

I will also be posting what chemicals are in highest proportional order (I realize that is the way that would make most sense now!)

Interesting, thanks for posting.

I recall finding a paper on GC-MS examination of Eucalyptus Globulus that might be of interest – available here

I’ve been wanting to do some similar work testing ground lavender buds versus lavender EO by headspace GC-MS to see “what’s missing” in the EO. Unfortunately I don’t know enough about the technique to run it myself, and I’m also worried about the implications of getting caught by my employer.

If you have other data, please share as I will certainly appreciate it. Maybe others too?

We are actually supposed to get a brand new headspace in the next year or so at my current position/job. I have lots of ideas of EOs to run (not that it will probably happen).

I haven't had a chance to run anymore on the GC MS. I'm in a different area of my site now (got offered a job that wasn't on nights) so I don't have the time/capability to run anymore.

I used to use one for analysing lipid content of algae. I hated changing the column so I can see why you didn't want to put a longer one on to resolve the other peaks. It's really interesting to see the differences. I guess it's due to the fact that even though the eucalyptus plants look the same there are big genetic differences between crops in different areas. In our algal strains that were so closeley related that you would never tell them apart microscopically and were pretty much identical genetically, the lipid profiles were quite significantly different, and could be altered even in the same strain by simply changing nutrient levels and growth conditions.

So what is the purpose? I dont understand.:eh:

Saponista, actually I was really just being lazy becasue we have 2 GC-MS with 2 columns each (4 diff total). It was just going to take an hour more per essential oil. That's very interesting about the algae. I guess it makes sense that nutrient content can effect lipid profile. I would think nutrients high in nitrogen would produce different lipids than a nutrient uptake low in nitrogen but high in something else.

Spice, this is sort of "just for fun" and interesting to see. Both are 100% eucalyptus essential oil yet the chemical nature of them differs pretty significantly which is why they smell different. I just wanted to see if I could identify the compounds/notice any differences and I did!

Spice -- a gas chromatograph (GC) is a special kind of machine only found in a chemistry lab. A GC takes a lot of care and fussing to keep running properly, but it is a pretty cool machine because it can tell you what specific chemicals are included in a particular essential oil (or other chemical blend). In this case, Galaxy tested two different kinds of eucalyptus EOs to see what blend of chemicals make up each EO.

Sometimes, if you know what to look for, you can tell if an EO has been contaminated or adulterated with chemicals that are not naturally found in a EO that comes from plant material only. You wrote in another thread about sandalwood, and I know sandalwood is often adulterated with synthetic chemicals. A GC can be used to figure that out.

Sometimes, if you know what to look for, you can tell what EO came from what part of the world or even what variety of eucalyptus tree was used to make a particular EO.

And sometimes, again if you know what to look for, you can tell from the GC results why you like the smell of one EO more than the smell of another. In this example, Galaxy likes the smell of the "Sanvall" EO because it smells more pine-y and citrus-y. These smells come from chemicals called pinenes.

^^^^ This, exactly what Dee said.

Thank you soooo much Dee! You are a lifesaver. Sometimes I don't know how in depth to get but somehow you always seem to go in depth just enough to explain things! Love it!

I often forget how to explain things/what someone may be trying to get out of an explanation/ question, and it is especially difficult in a forum setting. Again, thanks!

^^^^^I'm glad DeeAnna answered Spice before a I had the chance. My answer?


"They're lab geeks. We're not supposed to."

(I <3 you two. I learn, and get confused by, more stuff than I ever did in high school.)

It comes from a couple of decades of training people to run chemical plants and then teaching math and science to reluctant freshman and sophomore college students. I can fairly well follow what you (Galaxy) and Saponista are talking about, but I can also appreciate the viewpoint of someone who has never even seen a GC. It's a fun challenge to bridge between both worlds. I suppose it's similar to what a language translator does, although I can't speak a second language to know that for sure.

It's been quite awhile since I messed around with a GC so I remember the general concepts, but not any specifics. That means you two -- Galaxy and Saponista -- are going to have to explain the details if anyone asks!

I am so not the person to ask. I'm really not a chemist but had to use the gc-ms as there was no one else to do the work. My knowledge is very limited! I was terrified while using it that I would do something wrong and mess the whole thing up. I'm much more at home doing molecular biology with pcrs and trawling through sequence data

I would be really interested to compare rose geranium EO's though. I'm sure they adulterate the cheaper ones. I had an expensive bottle which smelled really floral and light and was a really pleasant smell. My soap didn't seize and after cure I was really happy with the soap. However the cheaper stuff seizes and smells what I can only describe as slightly pungent. It would have been really interesting to see the difference in profile and whether it had been diluted with something unpleasant.

*Geeking out ahead, sorry in advance!*

Wow, that would be interesting!! If someone sends me samples maybe I could try that... Hmm. I still have a good relationship with the people in that lab so they might let me run something. EOs are pretty gentle on these instruments.

I really do love my chromatographic instruments. Whenever we get a new one (liquid or gas) its so exciting! Ok, scratch that, I love new chemical instruments in general.

Saponista, I had a class once where we did pcr and I had to look at sequences ect. But its honestly pretty foreign to me! We had to identify certain sequences for certain traits in a plant tissue sample.

I made a boo-boo during the DNA extraction and the conical tube I was using EXPLODED in my face. Needless to say, DNA extraction isnt my thing. I ended up going to the infirmary and they had to write a report. I also learned to use the eye wash and at the same time my professor decided I needed the shower too. At least now I'm not afraid of using the eye wash anymore. Good times...

Was it a phenol chloroform extraction? If so I can see why having your face splattered in phenol may not have been the wisest of moves! I don't have any of the nice rose geranium left but if I get some more I will try and send it to you as I am genuinely really interested in the analysis.

I am also no novice to the eye wash. I dropped a glass bottle of acetone and it splashed into my eye and I got sent to the eye hospital. I didn't have goggles as I wasn't even planning on opening it! I also spattered random bacterial samples into my eye on another occasion. I still hate getting my eyes washed out though, it's not a pleasant experience!

No its not fun! And I don't think phenol was in there but we did have some mercaptoethanol in there so I stunk all day. It exploded from pressure building after grinding the plants in liquid nitrogen. It was so violent that the tube basically shattered and the contents were flung onto the roof.

Acetone and bacteria... Yum. Lol. Glad it sounds like you were ok after that though.

We used to prank each other by filling the eppendorfs with liquid nitrogen and dropping them in people's pockets. It goes off with an almighty bang lol! I probably shouldn't admit to that!

Saponista said:

We used to prank each other by filling the eppendorfs with liquid nitrogen and dropping them in people's pockets. It goes off with an almighty bang lol! I probably shouldn't admit to that!

Click to expand...

that's funny.

DeeAnna said:

Spice -- a gas chromatograph (GC) is a special kind of machine only found in a chemistry lab. A GC takes a lot of care and fussing to keep running properly, but it is a pretty cool machine because it can tell you what specific chemicals are included in a particular essential oil (or other chemical blend). In this case, Galaxy tested two different kinds of eucalyptus EOs to see what blend of chemicals make up each EO.

Sometimes, if you know what to look for, you can tell if an EO has been contaminated or adulterated with chemicals that are not naturally found in a EO that comes from plant material only. You wrote in another thread about sandalwood, and I know sandalwood is often adulterated with synthetic chemicals. A GC can be used to figure that out.

Sometimes, if you know what to look for, you can tell what EO came from what part of the world or even what variety of eucalyptus tree was used to make a particular EO.

And sometimes, again if you know what to look for, you can tell from the GC results why you like the smell of one EO more than the smell of another. In this example, Galaxy likes the smell of the "Sanvall" EO because it smells more pine-y and citrus-y. These smells come from chemicals called pinenes.

Click to expand...

galaxyMLP said:

^^^^ This, exactly what Dee said.

Thank you soooo much Dee! You are a lifesaver. Sometimes I don't know how in depth to get but somehow you always seem to go in depth just enough to explain things! Love it!

I often forget how to explain things/what someone may be trying to get out of an explanation/ question, and it is especially difficult in a forum setting. Again, thanks!

Click to expand...

You guys rock! That is amazing how all that chemical stuff works. Thank you so much for the insight, I was wondering why so much work and all that in depth research. It now brings the eos into a brighter light for me. How very interesting.:clap:

Saponista said:

I used to use one for analysing lipid content of algae. I hated changing the column so I can see why you didn't want to put a longer one on to resolve the other peaks. It's really interesting to see the differences. I guess it's due to the fact that even though the eucalyptus plants look the same there are big genetic differences between crops in different areas. In our algal strains that were so closeley related that you would never tell them apart microscopically and were pretty much identical genetically, the lipid profiles were quite significantly different, and could be altered even in the same strain by simply changing nutrient levels and growth conditions.

Click to expand...

I cant believe that now that I know what is happening I can understand in my mind the concept of a plant and its inviro. I dont want to sound like I am trying to be a geek, but I have always looked at origin when I order eos. I also noticed that some eo cost more from different countries too. :razz:

Another comparison I've always wanted to do by GC-MS is the overpriced, hyped brands (like Dotera and Young Living) vs. the more affordable good stuff from folks like NDA, etc.

I wish y'all would get to work.

Because some people showed interest and because I'm interested in it as well. I did this same experiment with 2 types of lavender EO. I did this with lavender EO from Now foods and Radha Lavender EO (found on amazon).

Now foods (NF) Lavender EO is supposedly French lavender EO whereas Radha is bulgarian lavender EO. The Radha (R) brand is much much cheaper so I wanted to know if it was adulterated with something. NF is a more herbaceous lavender while R is more floral.

Findings:
Neither lavender is adulterated. They both have a very similar profile except for a few differences.

Both contained: Eucalyptol, linalool, linalyl acetate, Caryophyllene, octanone, borneol, and lavendulol

NF has camphene but R does not. Camphene is the main component of camphor oil. This leads me to believe that if you want that more "herbaceous" lavender sent, you can add a bit of camphor oil.

R has many more terpines (lime-y scents) in it. It had alpha terpene, y-terpene, myrcene, omicene. But, NF only had one or two terpines along with D-limonene (main component of lemon EO) in a small amount.

This is all very interesting because it can give you a good idea of what will blend well with lavender.

For example, if you like a more floral lavender, it may be wise to add a bit of lime EO since lavender that is more floral naturally contains more lime-y scents (those are the terpines).

Now, if you want a more herbaceous lavender, you can add camphor oil to it or even a bit lemon EO since D-limonene is the main component of lemon EO.

Both of them contain eucalyptol which leads me to believe that lavender eucalyptus would be a wonderful scent combo.