Sciencemadness Discussion Board

How would one go about testing a substance for PEA?

Jhana - 24-11-2012 at 07:08

I have a nutritional supplement I strongly suspect has been adulterated with Phenethylamine CAS number 64-04-0. Is there any home test I can perform to confirm the presence of PEA if it were mixed with another substance?
If there is nothing I can do at home what options are there?

Would a Marquis reagent work? What color should it be? Where to obtain Marquis reagent?

Send for independent lab assay? Any recommended labs? Low cost?

Adas - 24-11-2012 at 07:55

What's wrong with PEA?

Sedit - 24-11-2012 at 07:59

We have to know what the other compound is so we know if there is a chance of it interfering with the test for PEA.

Nicodem - 24-11-2012 at 08:55

It is not possible to prove the presence of a substance by using indicators type of reagents. A positive response only gives an indication of the presence (they are called indicators!), but this is no evidence. A negative response is also not evidence of the absence of the substance, because an indicator reagent has its limits of detection and possible interferences with other analytes. But in general, a negative response is more conclusive than a positive one.

The closest to an analytical evidence you can get under simple home-friendly conditions is to run TLC analyses of your sample with a standard of phenethylamine under different conditions. If you always get a spot where phenethylamine should be, then this is can be considered chromatographic evidence (how reliable such evidence would be, depends on how many UV active analytes there are in your sample to interfere, and how many different TLC conditions you verified). Coupled also with an amine specific TLC visualization, this method can be considered quite reliable. For this specific analyte, a normal silicagel based TLC would not work well. You would need alumina, cellulose or polyamide plates (I'm not sure which one would be best) and a mobile phase with ammonia or triethylamine added.

The only conclusive evidence that you can do by primitive means is an actual isolation and characterization. The simplest method of characterization under primitive conditions is the mixed melting point measurement of a solid derivative (for example, a salt like a hydrochloride or a picrate, an amide derivative, etc.). For this, you again need a standard of phenethylamine. Without it, you can do a simple melting point measurement, but this is not conclusive evidence in the absence of other affirmative measurements (however, it is some evidence).

In conclusion, you can not get conclusive evidence with non-spectroscopic means unless you have a standard of phenethylamine.

Jhana - 24-11-2012 at 16:00

Quote: Originally posted by Nicodem  

In conclusion, you can not get conclusive evidence with non-spectroscopic means unless you have a standard of phenethylamine.


Thank you kindly for the help.

I have in possession what I am confident is a sample of high purity Phenethylamine.

The questionable substance is (RS)-4-amino-3-phenyl-butyric acid, CAS number 1078-21-3 (phenibut). Which should be relatively pure 99%+, but I believe is being cut with PEA.

I've worked with many batches of phenibut that I believe are of high purity. But I've seen quite a few batches that are extremely suspect and I believe a common adulterant is PEA. I feel confident a number of supplement wholesalers are cutting their phenibut with PEA, but would like some solid scientific proof.

If this can be proven I would look into legal ramifications and options.

chemrox - 24-11-2012 at 19:04

So do you have the ability to run a TLC? For the kind of situation you describe you would probably need to use a silica plate. Simpler analyses can be run with filter paper. In this case, pre-coated glass plates cut into strips would be handy. If you're not familiar with the technique maybe this is a good opportunity to read up and learn it. A mixture of polar and non-polar solvents are needed to separate the compounds. A drop of triethylamine will help keep the amine spots from spreading and "tailing."

Adas - 25-11-2012 at 04:38

First thing I would do: I would mix it with some NaOH. If it smells like fish, there is some amine (which may be PEA) present. Then I would go for other analyses.

Nicodem - 25-11-2012 at 13:39

Quote: Originally posted by Jhana  
The questionable substance is (RS)-4-amino-3-phenyl-butyric acid, CAS number 1078-21-3 (phenibut). Which should be relatively pure 99%+, but I believe is being cut with PEA.

...

If this can be proven I would look into legal ramifications and options.

It appears to me that you are not familiar on how the trade of API's and chemicals in general works. The seller must provide a certificate of analysis (CoA) where some typical specifications are listed. If you obtain a product that is out of specifications, all you need to do is to write a reclamation (and obviously not pay the bill). To check if the product is out of specifications, you do not need to prove the nature of the impurity. All you need to do is to measure any of the specified properties (assay and impurity levels are the most common ones). Your case is ridiculously simple. You bought a pure compound and if its mp does not fit the specified or literature value, that is already enough to make the reclamation. You don't even need to run an HPLC or do any spectroscopic analyses.

As to why would one want to adulterate a solid amino acid with a liquid amine (or anything at all), is beyond my imagination. Buyers usually do an analysis of the product they buy, so it is not in the interest of the seller to adulterate their product. Mislabelling, impurities out of specifications, and related errors or quality issues are common with the Chinese or Indian bulk sellers, but intentional adulteration of fine chemicals or API's is too irrational - it simply doesn't pay off.

chemrox - 25-11-2012 at 14:01

Quote:

As to why would one want to adulterate a solid amino acid with a liquid amine (or anything at all), is beyond my imagination.


This is of course the crux of the issue. Also PEA is not cheap enough to be used this way. A sugar or carbonate would be more likely. It does however provide you an opportunity to learn some analytical techniques you may not know. Was there an element of hopefulness in your post? b-PEA is pretty easy to buy....

zed - 28-11-2012 at 19:29

Yup, once upon a time, purchasing PEA was purely hypothetical. It wasn't legally restricted, but a chemical company buddy of mine suggested to me, that ONE...His employers surely wouldn't sell it to the general public, and TWO....His employers would contact the Feds if someone made a serious attempt to purchase some.

PEA is now a common supplement. Cheap and easy to buy.

SM2 - 29-11-2012 at 10:35

It would be obvious if your sample contained an appreciable amount of PEA. PEA is an oily liquid. It must be PEA.HCL, yes. And instead of buying phenibut, why not just buy baclofen.

Random - 3-12-2012 at 12:36

i wonder why are new members always asking for sources of only few specific chemicals...

amateur chemistry of peace