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Topic: How can I assay a substance?  (Read 7475 times)

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Offline daveyboy

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How can I assay a substance?
« on: April 30, 2010, 09:29:12 PM »
Hi, this is it a big vague and I am new so very sorry for the poor post.

I have a specific chemical that I purchased but I would like to know if the guy sold me the right chemical and how pure it is. How do I go about this? Is there lists of reagents for specific susbstances say, other techniques... All I will say about the substance is it is not an illegal or controlled substance. I do have good reasons for not saying more which I hope you will take on faith. Any help you can give with such limited info is much appreciated. Thank you.

Offline Train

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Re: How can I assay a substance?
« Reply #1 on: May 01, 2010, 12:51:42 AM »
You could try checking Reagent Chemicals from ACS or see if there is a USP or NF monograph. 

Offline Borek

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Re: How can I assay a substance?
« Reply #2 on: May 01, 2010, 04:27:04 AM »
You are in a relatively good situation - you know what to look for. Depending on what the substance is, there are either well defined methods for this particular substance, or there are methods suitable for analysis of similar substances, and they can be applied. Not knowing what the substance is, it is hard to help further (although Train suggestion makes a good starting point).
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Offline 408

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Re: How can I assay a substance?
« Reply #3 on: May 01, 2010, 08:06:58 AM »
Easiest way if you have access is elemental analysis...  You local university may be able to help you for a fee. 

Offline Borek

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Re: How can I assay a substance?
« Reply #4 on: May 01, 2010, 08:52:27 AM »
Elemental analysis won't help in the case of organic compounds.
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Offline daveyboy

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Re: How can I assay a substance?
« Reply #5 on: May 01, 2010, 09:09:09 AM »
Elemental analysis won't help in the case of organic compounds.

Remember I'm still very naive but I thought organic compounds were ones which had carbon in. I can't see a C in the molecular structure of this chemical...

Offline daveyboy

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Re: How can I assay a substance?
« Reply #6 on: May 01, 2010, 09:16:33 AM »
Elemental analysis won't help in the case of organic compounds.

Thanks a lot and I will probably decide to send some off to a real lab to have it tested seeing as my potential business associate (I can give him a service he wants which has nothing to do with chemicals) has decided to send me triple my order as a "we should talk more" gesture so now I have some to burn.

I still would love to do this at home though if at all possible. I'm prepared to put in quite a bit of homework once I know the best method. This "Automatic Potentiometric Titrations" mentioned may have some benefit?

Again sorry for trying to walk before I can swim, but once I know a definite method which I can do relatively cheaply to do the analysis I can simply work backward to pick up all the other knowledge and equipment I need to know in order to do it.

Offline Borek

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Re: How can I assay a substance?
« Reply #7 on: May 01, 2010, 10:44:13 AM »
Remember I'm still very naive but I thought organic compounds were ones which had carbon in. I can't see a C in the molecular structure of this chemical...

You have not stated what the chemical is, it can be organic, it can be inorganic - we can't say, I was just clarifying that 408 idea can be inadequate.

Again sorry for trying to walk before I can swim, but once I know a definite method which I can do relatively cheaply to do the analysis I can simply work backward to pick up all the other knowledge and equipment I need to know in order to do it.

Sorry, but not knowing - even approximately - what the substance is we can't help you to select the method.

What you are doing at the moment is you are trying to ask Radio Shack clerk what chip you should buy to repair your TV. "You know, it blew that blue smoke from the left, what element do I have to replace?"
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Offline daveyboy

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Re: How can I assay a substance?
« Reply #8 on: May 01, 2010, 01:08:49 PM »
Oh right, I am so sorry it's just ignorance you will forgive me. Substance is C15H10BrClN2O. Although if I recall there are two very different substances which are written as C17H21NO4 and getting them confused would be a very bad thing. How should substances be referenced? CAS number? CAS is 51753-57-2. PubChem is 40113. I'll re-assert I checked very carefully that while importing this substance into the UK would be (possibly) illegal, possessing it here isn't, nor is manufacturing it here and nor is possessing it in the USA (because of the schedule it doesn't fall under analog laws).

I'm trying to keep it low key because some greedy fool without a conscience will start selling it to the wrong people and I know exactly what will happen when that does. However it has helped me solve some very big problems in my life, so I'm keen to keep it off the radar of those sorts of people.

And to add finally I'm not asking how to make this stuff, I just want to be able to analyse it with cheaply available equipment/reagents if possible.
« Last Edit: May 01, 2010, 02:08:34 PM by daveyboy »

Offline 408

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Re: How can I assay a substance?
« Reply #9 on: May 02, 2010, 03:39:23 AM »
Elemental analysis will work with such a compound, but it will not distinguish between isomers.  Borek I was not referring to the ICP/AAS type EA, but to the CHNO, etc percentage method.  Which works on most things, unless it has very very high nitrogen contents (>60-70%) in which case nitrogen occurs low.

Offline DrCMS

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Re: How can I assay a substance?
« Reply #10 on: May 02, 2010, 09:07:58 AM »
So what you are talking about here is Phenazepam which is a benzodiazepine drug which has not be classified as an illegal drug in the USA.  It is however illegal to sell things like this when you know the person you are selling it too is going to ingest it when you are not a doctor/pharmacist.  So I think anyone who continues to answer your questions is complicity in the illegal sale of drugs.  If you want to make a fast buck you can do whatever stupid illegal things you want but I will not help you do it and I think anyone else on this board who does help you should be ashamed.

Offline daveyboy

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Re: How can I assay a substance?
« Reply #11 on: May 03, 2010, 01:29:39 AM »
So what you are talking about here is Phenazepamwhich is a benzodiazepine drug which has not be classified as an illegal drug in the USA.

Therefore not breaking the forum rules...

It is however illegal to sell things like this when you know the person you are selling it too is going to ingest it when you are not a doctor/pharmacist.

I have no intention of doing this I just want to know what I am taking.

So what you are talking about here is Phenazepam which is a benzodiazepine drug which has not be classified as an illegal drug in the USA.

Therefore not breaking the forum rules...

So I think anyone who continues to answer your questions is complicity in the illegal sale of drugs.

I don't sell drugs so they are not but it's easy to see how you arrived at that conclusion.


If you want to make a fast buck you can do whatever stupid illegal things you want but I will not help you do it and I think anyone else on this board who does help you should be ashamed.

I am not looking to make money. This is for my own personal health only. Plus although I really started looking into chemistry due to drugs I've become quite curious in it for it's own sake and am thinking maybe of looking for a career in something such as materials science.

Now, you are fully entitled to believe what you like but I have told you the truth and as it is the truth, none of your morals should have been violated.

My reticence in discussing this in fact was precisely because I didn't want some low-life finding the thread on goggle and getting any ideas. You think a distributor bothers to assay their product? This isn't how it works in the real world. I only supply the next paragraph too so as to prove it isn't worth my financial while to assay it personally as you are forcing me to defend my moral intentions, I'd really rather the paragraph wasn't there and hope we can find some way to get rid of it once you can see I'm telling the truth.

If I wanted to make a fast buck I'd just ship it in by the kilo from china FOB for $800 a barrel, not bother assaying it and sell it to any old tom Joe or Larry at $50 a gram.

This substance very probably saved my life and helped me to become a more useful member of society. It was not morally wrong for me to use it for my own personal use and I discourage others from using it and will never supply it to them.
« Last Edit: May 03, 2010, 01:49:28 AM by daveyboy »

Offline daveyboy

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Re: How can I assay a substance?
« Reply #12 on: May 03, 2010, 01:52:02 AM »
The ideal would be for me to be able to make it for myself for my own personal use in small quantities, which I would then assay to know I did a good job, but as I understand it, this type of chemistry is actually very difficult despite the low product prices.

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