What are the reagents?

[ChrisV]

Couldn't find this anywhere in the archives, soo:
What is the chemical composition of the reagents used in pill testing? Mecke, Simon's, Robadope, and the fixing agent.
I know Marquis is 9:1 sulfuric acid/formaldehyde, with methanol added sometimes to slow reaction speed.
Thanks
Chris

 

[djfriendly]

Feeling too lazy to fetch the URL, but the NIJ color reaction chart (which I understand is available here somewhere, presumably in the archives or faqs) has an appendix with the formulae.
Question: Is the Robadope reagent listed in this document under a different name? I'd be interested in more information about this test.

 

[johnboy]

Answer: No Robadope isn't covered by that document. Most other chemists I have spoken to don't put much faith in Robadope, but it is a very specialised test that (hopefully) detects what we need.
That NIJ document is here

 

[aj]

"it is a very specialised test that (hopefully) detects what we need."
I showed a proper reaction to Soma and gave him two testkits. Hopefully he will spread the knowledge of small changes in color ;-)
It worked really wonderful, as usual.
Just be very sure to only use one drop of bottle 3 and at least two drops of bottle 2.
A good trick is to drop Robadope next to the scraping and if it seems to much (more than one drop), just use a little bit of tissue and remove a little bit of reagent. Then shove the scraping into the Robadope (with a knife). The scraping and Robadope 'come together', then add two drops of bottle 2.
aj

 

[johnboy]

aj: Yay! Hopefully he doesn't lose em and I get one. chances are he'll forget everything you showed/told him tho
And I wasn't dissing Robadope, just passing on what has been said to me. Actually I am very much looking forward to doing extenisve testing with it.

 

[Roches]

it should be in the archives, because i've posted it before =)
here:
Simon's reagent is sodium nitroprusside (also known as sodium nitroferricyanide, Na2Fe(CN)5(NO)·2H2O), which is the active reagent. It is a test for secondary amines. Since secondary amines (e.g. R-NHCH3) have one and only one hydrogen on their amino group, I am guessing that the nitro group (nitro groups are good 'leaving groups' in inorganic chemistry) substitutes with that hydrogen and forms a drug-ferricyanide complex. ferricyanides are typically quite colored. Simon's reagent also contains sodium carbonate (Na2CO3) as a buffer, so that the reaction occurs under basic conditions.
Mecke reagent is selenious sulfuric acid, and turns green in the presence of indoles, furans, and compounds with phenolic oxygen.
Mandelin reagent is vanadyl sulfate.
I don't know the exact mechanisms for Mecke or Mandelin reagents... nor do I have any idea whatsoever what Robadope is... i've looked it up in Chemical Abstracts and in several very old qualitative analytical chem textbooks, and i've found nothing at all.