How does GC/MS testing at EcstasyData compare with other labs?

[Zucchini]

Hello everyone. I'm new here and looking for advice about how to verify the purity of a schedule 2 substance in powder form. I'm located in the US.

I am considering using EcstasyData.org, but I'm also wondering if there would be any advantage to consulting a different lab. I realize it would be quite expensive, but this is very important to me and I'm willing to pay.

Does anyone have knowledge of how the GC/MS testing done for EcstasyData compares with the same service at other labs? I'm a bit concerned because the $120 price seems very inexpensive compared with the pricing elsewhere. Does this mean that the analysis is less detailed? Or that the range of detectable substances is narrower?

My other concern with EcstasyData stems from the fact that the results are presented as a ratio with no quantities given. Someone told me that this wouldn't matter when testing a powder, since there are no binders or fillers as with pills. One can assume that the resulting ratio applies to the whole sample of powder. For example, if the result is a 2:1 ratio of acetaminophen to caffeine, that means that the weight of the powder is 2/3 acetaminophen and 1/3 caffeine, since there are no fillers as with pills. Is this true?

If anyone out there has ever sent a substance to a lab for analysis, I would love to hear about your experience. All other advice is appreciated as well. I'm a total beginner at this, with no chemistry background whatsoever, and I'm finding it all rather confusing.

Thanks

 

[sekio]

Only active substances are recorded (to the best of my knowledge), binders and fillers in powders are often much harder to qualitatively identify (as GC/MS requires the substance dissolve into a solvent). If you have some modicum of basic chemistry knowledge you can see how much of your substance dissolves in various solvents to get a rough approximation of how heavily cut it is.

 

[nuke]

The ratios are based on elution areas under the curve and not on weight, so it will be in regards to active compounds. The low fee is because this is a harm reduction service; the lab is very professional and employs forensic toxicologists and chemists.

Note though that if they do not have a reference spectrum for you compound, they'll tell you it's an unidentified substance. You could e-mail them about performing 1H-NMR and 13C-NMR in that case, which will probably resolve what you have.

 

[Zucchini]

Thanks for the feedback. It's frustrating that it's so difficult to get a conclusive result as to purity.

I've read on EcstasyData's site that there are legal reasons for reporting the data only as a ratio of active ingredients instead of giving exact quantities. i.e the DEA doesn't allow it for anonymous samples. I assume this means that there's no technical reason why they couldn't determine exact quantities of each ingredient, if you provide your real name when submitting the sample?

This may be the stupidest question ever asked on this forum, but what happens if you do give your real identity? Are labs obligated report you to the police? In my case, the substance is schedule 2, so it is (remotely) possible for someone to have a legitimate prescription for it. Has anyone ever tried to have a sample tested non-anonymously?

)If you have some modicum of basic chemistry knowledge you can see how much of your substance dissolves in various solvents to get a rough approximation of how heavily cut it is.

Can you elaborate on how this would work?

 

[skillet]

I think the majority of fillers/binders commonly used in pills are mostly insoluble in water, while the active drugs usually are. Or maybe ethanol would be better to use. Anyway, you'd weigh out a certain amount of the powder/pill and dissolve it, as much as possible, in water/ethanol. Then filter the insoluble material, dry it and weigh it. The difference between this weight and the initial weight is the amount that went into solution, which should roughly equal the amount of drug.

If you know what the drug is maybe you can find the solubility online somewhere and get an idea of how much solvent you'd need.

 

[Zucchini]

Thank you, skillet. That sounds simple enough that even I could do it!

 

[skillet]

Well, it's simple in theory, but if you don't know what else is in this powder you can't be sure that you're only dissolving the drug. So the result might be totally wrong.

You could try and verify that the solution that passed through the filter contains only the drug, by concentrating it and checking the melting point for example, but that's probably a bit out of reach of most people.

 

[vecktor]

plenty of binders and fillers are water soluble.

the use of GCMS to quantify something requires a series of genuine diluted reference samples to be injected into to the machine using the same conditions as the test sample. This gives a calibration curve which can be used to calculate how much is in the unknown. Usually all that has to be done is the major peak. this is a load more work.

if the material is reasonably pure or the fillers are different chemically then an easy way to quantify the purity is to use GCMS to discover what is there and then use UV-VIS to measure the absorbance of an accurately diluted sample and compare it to the absorbance of a known amount of material.

If the material has acidic or basic groups and the fillers do not then it can be titrated with base or acid.

it is rather unhelpful if you don't say what the substance is, quite a few substances have well tested assay methods in the literature.

 

[skillet]

Ok, but ethanol, isopropanol? I can't really imagine many pill additives dissolving in those, but of course it's impossible to say without knowing what we're talking about.

 

[Zucchini]

The substance in question is supposed to be sodium pentobarbital, CAS# 57-33-0. It's in powder form, not a pill, and it's supposed to be >98% pure according to the company I bought it from. I have no particular reason to believe it's impure, but I'd like to be as sure as I possibly can be before using it.

It seems to me that if I send a sample to EcstasyData and (hopefully) get a result back that pentobarbital is the only active ingredient, I still won't know if the powder is 1% or 99% pentobarbital - all I will know is that there are no other ingredients detectable by GC/MS. So that's the difficulty I'm facing.

I do know that sodium pentobarbital is very soluble in both water and alcohol. Perhaps if I do get the desired result from EcstasyData, I could do a solubility test to eliminate the possibility of any insoluble, non-GC/MS-detectable impurities. Of course, there could still be soluble, non-GC/MS-detectable impurities present...

I really want to thank all of you for sharing your knowledge with a newbie. I swear, I've never before so fervently wished I'd paid attention in HS chemistry.

 

[vecktor]

there is a very old fashioned method in the USP specification

http://lib.njutcm.edu.cn/yaodian/ep/EP5.0/16_monographs/monographs_l-p/Pentobarbital sodium.pdf

ASSAY
Dissolve 0.200 g in 15 ml of a 127.5 g/l solution of silver
nitrate R in pyridine R Titrate with 0.1 M ethanolic sodium
hydroxide until a pure blue colour is obtained, using 0.5 ml
of thymolphthalein solution as indicator. Carry out a
blank titration.
1 ml of 0.1 M ethanolic sodium hydroxide is equivalent to
24.83 mg of C11H17N2NaO3.


there should be a much more convenient UV absorbtion method somewhere, barbiturates absorb at a maxima of 240-250nm I am sure the extinction co-eficient is published somewhere.