Calcium nitrate (Calgon, take meth away)

Friday, I alluded to a chemical in the House version of the farm bill. It's calcium nitrate.

Many meth cooks use a modified version of the birch reduction, which involves using an alkali metal (lithium here) in liquid ammonia. Lot of farmers use anhydrous ammonia (which is just barely a gas - put it in a tank much like a propane tank, and it's a liquid) to fertilize their crops. Predictably, this has led to a lot of meth cooks stealing ammonia from farmers.

This is dangerous not only because of the drugs, but because of the ammonia - anhydrous ammonia is an entirely different beast than cleaning ammonia (which is just a solution of the stuff in water). It boils below zero, is toxic and caustic, and it expands avidly when warmed (since it's boiling away to gas). A beat-up propane cylinder might contain it, it might not. God help the guy who tries to fill his thermos with it and seals it up.

Getting rid of ammonia just isn't an option. The Haber-Bosch process, invented a mere 100 years ago, gave us the necessary catalysts to convert aerial nitrogen (0) (ubiquitous and inert) to fixed nitrogen (III) (rare and utile). Nearly half the world gets protein nitrogen from Haber-type ammonia. It's a big part of how we manage to grow so much damn corn.

Another suitable nitrogen-bearing fertilizer is nitrates - salts of nitric acid. Calcium nitrate, CaNO3, will dissolve in ammonia quite nicely, provide a tiny amount of additional "fixed" nitrogen, and, as an added bonus, poison Birch reductions. It's ammonia that doesn't work very well for meth production.

The current House farm bill contains a pilot program for grants to put Ca(NO3)2 in anhydrous ammonia tanks.

NB: I'm aware this isn't a perfect solution. Please don't post any thoughts related to circumvention in the comments. I am always leery of posting this kind of drug-related entries, particularly those related to synthesis, and I opt for the overly conservative tactic of just not posting anything that could be possibly construed as instructional. I don't want that kind of attention or those kinds of readers. I'm overcautious here, so if your comment doesn't get approved, that's why. Sorry!

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I understand that meth is a problem (I consider it more dangerous than cocaine) so I applaud the effort to make (farm) ammonia unusable for synthesis, however, separating a nonvolatile contaminant from a volatile substance is not all that hard.

It's gonna slow down the guys who make it from a cookbook recipe but I'm gonna say the guys who know their chemistry already got this worked out.

Oh, I see you asked for no discussion of circumvention...what the heck is your whole post about? If you're gonna discuss ways to effectively contaminate substances, that necessarily involves a discussion of the feasability of circumvention.

Very well, that leaves, um, this tidbit: Calcium nitrate has a mol. wt. of 102!

Is the formula for calcium nitrate altered on purpose?

By syregnask (not verified) on 30 Jul 2007 #permalink

Ha, you think that's bad? My final exam for O-chem had a synthesis problem where we had to outline a step-by-step method to make methamphetamine! Talk about an irresponsible professor!

I think synthesis of ortho and dextro meth is standard in o-chem labs. We covered the hell out of it. Our professors take was that more of the problem can be solved by extensive education and understanding. Also had a seminar on meth that was attended by law enforcement as well as collegiate's. Covered synthesis, methods of action, glassware restricted by law but of use to chemists, etc. I bet none of us went on to be meth cooks.