What is a GC or GC/MS

[Guest guest]

Hey Carmen and other good folks,

 

You won't believe this maybe .. but I spent the last hour cutting this

back .. by maybe 65% .. and it still might be too long. Most of this is

not important to the end-user but I'll throw it out to those who want it

and try to keep it short as I can.

 

GC means Gas Chromatography - it's an analysis of an essential oil or

other solvent to determine the chemical profile - sort of like a blood

test but a lot more complicated and more expensive.

 

Tells you what's there and in what percentage.

 

Then there's a test called GC/MS which is GC plus Mass Spectroscopy -

and to simplify it's a mass detector to determine the specific gravity

or molecular weight of a given chemical component. Refractive Index and

Optical Rotation are further tests to determine purity and quality of an

oil, but they are becoming less important due to technological advances

 

Then we get into Optical Rotation or Optical Chirality which detects the

way certain chemicals rotate a beam of light - to the left or the right

or whatever. Chiral chromatography is the identification, isolation and

separation of enantiomeric compounds. It gets into polar and non-polar

environments and enantioselectivity, etc.

 

Forget the above unless you are interested in learning more. ;-p

 

Another technique is GC/FT-IR .. Gas Chromatography/Fourier Transform

Infrared Spectophotometry. This technique is also useful for analysis

of EOs since it's possible to create archieves or use commercial PC

libraries during the analysis. But its not as popular and simple as

GC/MS and it doesn't help the one paying for the analysis as much as it

does the analyst .. so forget it.

 

There are a dozen or so techniques other than GC/MS, Infrared or Planar

Chromotography being a couple of those in fairly common use, but GC/MS

is an established and reliable technique for analyzing essential oils

and unless we get into something deep - not likely as we're not into

chemistry projects, it's as much as we'll ever need - or wanna pay for.

Its all you'll get from me and more than you'll get from most folks.

 

The finest equipment can be defeated by a weak analyst - technicians

must know what they're looking for .. need a standard for comparison -

that is, they need to know what should be the profile of a typical

sample of Origanum vulgare produced from wild-grown plants harvested in

Central Anatolia or the expected results of a Lavandula stoechas from

France versus one from Turkey - there will be differences, and that's a

another very important reason to know the ORIGIN of an oil.

 

The analyst looks at the chemical profile to see if it fits within the

" footprint " or " range " they think is acceptable for the oil .. because

even a pure oil can be a mediocre oil.

 

Pure but Mediocre oils should be sold as commercial oils to the food,

pharmaceutical and soaping industries because when they finish playing

with them they'll have lost the original identity anyway. Unfortunately,

many lower grade oils make it into the Aromatherapy/Cosmetics market.

 

Smart chemists can fool a GC but distillers from third world or emerging

markets can't manipulate oils very well and generally wouldn't mess with

it if they could as it's expensive and time-consuming. French labs are

good at this, especially with 40/42 lavender which is manipulated in a

well-equipped lab. The Great Spirit doesn't allow the same growing

conditions year after year but perfumers want consistency in lavender so

they doctor it up a bit. It takes more than GC/MS to detect this - but

Chiral Column testing can usually do it if the analyst is experienced.

Normally, they don't try to deceive you, they just sell the 40/42 and

it's up to a buyer to know what they're getting cause sellers of 40/42

lavender often don't know themselves what they have. I've said and

written many times before, Caveat Emptor.

 

An experienced analyst looks for what's not there as well as for what's

there - if you increase one side of an equation, you decrease the other

side - pure physics. Absence of a chemical that's normally detected at

..01% tells a lot to the smart analyst. If I increase major chemicals to

get a more favorable product, I'm lowering the percentage of minor trace

components - and we don't really know exactly why a particular oil has

therapeutic value but as we know the Great Spirit didn't put unnecessary

chemicals in the oil to fill a void we logically conclude that upsetting

that natural synergy has negative effects on the therapeutic value.

 

Many people tell you their EOs are GC tested and its often pure hogwash.

Generally, they're told that by their source and they believe it (wanna

believe it) and just pass along the information - they are generally

niave, not dishonest, but I see it as being a little bit irresponsible

because I believe we should trust everyone but always lock our car.

 

If someone tells you their oils are GC tested, ask them to put up or

shut up. You'll probably get a lot of shuck and jive but no GC!

 

Without Lot Numbers there is potential for a seller to create an alibi

of error but with Lot Numbers, if they're caught short there's no avenue

of escape. Sellers who buy but 16 ounces from a source that does not

provide them a GC can't afford to pay $150 and up to test that 16 ounces

of oil so they're running on luck and/or guts.

 

Most laypersons can't read a GC so I generally have the analyst make

comments at the end that can be understood by the average buyer. Also,

I refuse many of the oils I test .. they're pure .. but mediocre.

 

I won't say that folks making soap need to buy tested oils because they

can get by with PURE commercial grade oils .. purely from a point of

safe use. BUT if the oil you're buying for soap contains 50% synthetic

chemicals that cost $5 a kilogram and you're paying $50 a kilogram for

the oil, it's not a matter of just safety - it's a matter of getting

ripped off. MANY people and companies in this industry have been caught

selling adulterated essential oils .. it's a matter of greed.

 

All (including commercial grade) unadulterated essential oils are safe

if used correctly and responsibly but some require a lot more attention

to detail. Adulterated oils can be harmful depending on the nature of

the adulterant used and some folks aren't as ethical as others - this

holds true for Fragrance Oils as we have no idea what they contain. And

a pure oil can be dangerous if the user is careless or irresponsible.

 

Was the explanation short enough ?? .. ;-) Ask me questions if you have

any .. I'll answer tomorrow cause its after midnight here and I worked

all night last night .. gonna sack out now. But afore that I'll tell

you that I am NOT an analyst .. I have mine done by smarter folks .. but

I can read and compare them and that's enough for me.

 

Y'all keep smiling, Butch http://www.AV-AT.com