First and foremost I'd advise anyone not familiar with handling these chemicals not to carry out this procedure, or at the very least read the MSDS sheets for
Shellite and
Sodium Hydroxide (caustic soda or NaOH) These procedures are simple enough, but accidents seem to be common.
Most importantly
* NaOH causes nasty burns
* Naphtha and Shellite are highly flammable
As most procedures call for heating the Naphtha/ DXM solution, care must be taken:
1) safeguard against the possibility of burns
2) pick an appropriate environment
3) have a suitable extinguisher on hand if large amounts are used.
There's also at least one Bluelighter who learned the hard way about handling caustic soda without taking proper precautions. Always wear gloves and eye protection while handling NaOH, and never touch your face with contaminated gloves/hands.
1. Is Shellite an okay substitute for naptha? I read somewhere that someone had a bad experiance using it
Naptha is a general term used to describe a blend of hydrocarbons, (also termed petroleum ethers, although these are not true ethers as the compounds don't contain an -O- linkage). Different grades of naphtha contain compounds with different carbon chain lengths, and so different boiling points. Some of the heavy naphthas have boiling ranges that go up to 200 *C. Light Naphtha is typically a mixture of compounds with 5-6 carbons, with boiling points between 30-90*C. Shellite is a mixture of light Naphtha (including n-hexane) and ethylbenzene, with benzene as an impurity typically present at less than 0.1% (note: benzene is a known carcinogen, and ethylbenzene is classed as a possible human carcinogen) Shellite will do the job as far as extraction goes, but it's important for health reasons that all traces of solvent be completely removed via evaporation; use a vacuum desiccator if available.
2. I heard you could use NaOH (drano?) instead of clear Ammonia but that its also a stronger base, does that change the ammount i need to use?
It's difficult to say how much ammonia is in the standard household solution, probably 1-2moles/litre, but it's helpful to know how much of the amine (DXM) is in the product. Using something found elsewhere, it is stated an 8 oz (~240mL) bottle of Robotussin contains 708mg of DXM. Assuming this is measured as the hydrobromide salt, then there is just over 2 moles of DXM HBr present (708mg/ molecular weight of DXM HBr which =352.31g).
If substituting NaOH for NH4OH, it would probably be best to prepare a 3.0 molar solution (12g NaOH/100mL water). NaOH + H2O is very exothermic - care is needed if large amounts are prepared, and a suitable container a must! The cooled solution would then be added bit by bit to the DXM containing solution -shaking, swirling, stirring etc - until the pH is around 10. A pH meter or indicator papers are used for this. The total volume of added alkali solution is not critical but DXM has a pka of around 8.3 so the solution pH would need to be kept higher than this to liberate all the freebase. The resulting precipitate would be extracted with the non polar solvent (Shellite).
In answering these questions, I suggest before deciding to go ahead with this extraction the op gives considerable thought to the increased dangers that accompany high dose consumption of concentrated DXM, and whether the legal implications of being caught either preparing or in possession of a purified product are worth it. I don't recommend it for these reasons.
![:\](https://bluelight.org/xf/BL_Images/Orig_Emoji/wrygrin.gif "wry grin :\")
