What Is A GC ?

[Guest guest]

Hi Lori,

 

> Kathleen,

> Thanks for the info. I don't mean to sound dumb, but what is a gc?

> Lori

 

Not Kathleen here .. Kathleen is better looking than I am .. in fact,

everybody is better looking than I am .. but I do have some info on what

a GC is. ;-)

 

Here is a part of a post I have made to this list many times before.

 

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

determine the chemical profile - sort of like a blood test but a lot

more complicated and more expensive. We also have a test called GC/MS

which is GC plus Mass Spectroscopy .. to simplify it's a mass detector

to determine the molecular weight of a given chemical component.

 

We can go into Specific Gravity, Refractive Index and Optical Rotation

which are further tests to determine the purity and quality of an oil.

 

I'll add here that the above three indicators do NOT mean an oil is

pure .. but only that its within the range normally expected .. and that

normal range is but a hair or two wide so the lazy thing some analysts

do is just record these three specs as being within that range. Thus,

folks are getting away from the demand for Mass Spectrometry.

 

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

Chromatography being a couple of those in fairly common use, but GC and

GC/MS are the normal techniques for analyzing essential oils.

 

Another technique GC/FT-IR, which stands for Gas Chromatography/Fourier

Transform Infrared Spectophotometry. This technique is also useful for

the analysis of EO since it's possible to create libraries (archives)

or use commercial libraries during the analysis. But it is also 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.

 

I'll stick to GC or GC/MS as they are widely accepted techniques and

unless I get into something technically deep - not likely as I'm not

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

 

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

must know what they're looking for and they have to know the standard

for comparison - that is, 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 very

important reason to know the ORIGIN of an oil.

 

I have all of my oils GC of GC/MS tested for a number of reasons but for

oils we produce here in Turkey, it has nothing to do with determining if

the oil has been adulterated - I know it hasn't as I know it came

directly from the still. But I am looking for the chemical profile to

see if it fits within the " footprint " or " range " that we think is

acceptable for that oil because even a pure oil can be a mediocre oil.

 

Mediocre oils are (should be) sold as Commercial Grade oils to the food

and pharmaceutical and soaping industries because when they get through

playing with them, they will have lost part of their original identity

anyway. Unfortunately, many of these lower grade oils make it into the

Aromatherapy market ...

 

As I'm able to contract my distillation here in Turkey, I test so I can

avoid accepting Commercial quality oils - my target is the AT industry.

 

Smart chemists can fool a GC/MS but distillers from Third World or

Emerging Markets can't manipulate oils like this and wouldn't mess with

it if they could as it's too expensive and time consuming. The French

are extremely good at this, especially with their 40/42 lavender which

is manipulated by man in a well equipped laboratory. The Great Spirit

doesn't allow the same growing conditions year after year but they want

consistency in that 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, folks don't try to deceive you, they just sell their 40/42 and

it's up to the buyer to know what they're getting because the sellers of

40/42 lavender often don't know themselves what they have - like I've

said and written many times before, Caveat Emptor ....

 

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

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

other side - pure physics. The absence of a chemical that's normally

detected at .01% tells a lot to the smart analyst. If I increase the

major chemicals to get a more favorable product, I'm lowering the per-

centage of minor trace components - and we don't really know exactly why

a particular oil has therapeutic value but we can bet that the Great

Spirit didn't put any unnecessary crap in that oil just to fill a void,

so we logically conclude that upsetting that natural synergy will have

negative effects on the therapeutic value.

 

I've sold lots of oils in 100 kilogram lots, and I've never exported

an oil without providing a GC test because big buyers want it and I want

it because I guarantee that all my products are pure and unadulterated

and my name is more important to me than money. I keep my credibility

propped up as that's an inherent part of my interpretation of what's

ethical and moral when dealing in Aromatherapy Grade oils.

 

BUT, those who buy those bulk oils sell to wholesalers who pass them to

retailers who pass them to end users and I'll bet you a pretty that you

cannot get a copy of that original GC test that I gave the bulk buyer -

the first buyer! Why? Danged good question, huh? We can guess the

answer has something to do with identity change - the oil profile may no

longer resemble the original GC analysis. It's not your retailer who is

messing with those oils - your retailer is also a victim but they are

helping to victimize themselves by not demanding a copy of that GC!

 

Many of my wholesale/retail customers ask for GCs on new oils I sell -

not that they can read them but they want them.

 

I am not going to say that folks making soap need to buy tested oils

because they can get by with Commercial Grade oils .. and I'm speaking

purely from a point of safe use. BUT - if the oil you are buying for

making soap contains 50% synthetic chemicals that cost $5 a kilogram and

you are paying $50 a kilogram for that oil, then it's no longer a matter

of just safety - it's a matter of you getting ripped off. Take my word

for it .. 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 - like cinnamon bark. 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. Likewise, a pure oil can be dangerous if the

user is careless or irresponsible.

 

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

 

Bulk/Wholesale/Retail GC Tested EO, Rose Otto, Hydrosols, Rose Petal

Jam, Turkish Robes and lots of other nice things.