general chemistry

If Jim Henson Taught Chemistry

I’ve had a few people tell me about this video, and saw it on BoingBoing as well. It’s creative, if not terribly informative, I guess I don’t know what I should expect from something like this. I do know I thought that at least one fuzzy member of the cast might be of help when cleaning glassware.

By October 22, 2009 1 comment fun, general chemistry

Meth and mirror images: errors in Nick Reding’s “Methland”

meth-3

I recently picked up Nick Reding’s book Methland, which is about the blight of a small Iowa town due to methamphetamine use. I was interested in it because I had heard about it from NPR; I was interested in what Reding had to say about the chemistry of meth synthesis. What I found was pretty amusing.

I should pause to say that Reding was not focused on the chemistry at all — rather, his thesis was that meth was a mere symptom of the devastating effects of global economic forces on a small Iowa town. It’s well written and pretty gripping stuff.

I’m sure I’m not the only chemist who can get distracted by chemical explanations that’s just obviously wrong. But some of the explanations were just terribly, terribly wrong:

“Mirror imaging is a process whereby a chemical’s molecular structure is reversed, moving, for example, electrons from the bottom of a certain ring to the top, and vice versa. Pseudoephedrine, ephedrine, and methamphetamine are already near mirror images of one another. To make meth from ephedrine, it is necessary to remove a single oxygen atom from the outer electron ring. Thus ephedrine and methamphetamine not only look the same under a mass spectrometer, but both dilate the alveoli in the lungs and shrink blood vessels in the nose-hence ephedrine’s use as a decongestant while raising blood pressure and releasing adrenaline. The key difference is that meth, unlike ephedrine, prompts wide-scale releases of the neurotransmitters dopamine and epinephrine.

What the 1997 tests at the University of North Texas showed was that, at least in lab animals, mirror-image pseudoephedrine was equally as effective as regular pseudoephedrine as a decongestant. Unlike regular pseudo, however, the mirror-image version didn’t cause any side effects to the central nervous system, such as high blood pressure and a racing heart: the common “buzz” that one associates with cold medicine. Better yet for Warner-Lambert, mirror-image pseudoephedrine could only be synthesized into mirror-image methamphetamine, which, according to the Oregonian, had no stimulant effects and could not then be made into regular meth.” (quote thanks to Mike the Mad Biologist.)

Where to begin? First of all, “mirror imaging” is not a term; the word you’re looking for is, of course, enantiomers. The explanation about electrons is not correct; you can’t move electrons willy-nilly around rings. The comparison of ephedrine and methamphetamine as mirror images is wrong — they’re not even structural isomers. To make meth from ephedrine, you don’t “remove a single oxygen atom from the outer electron ring” (that sounds like something you do on the planet Zefu), you remove an oxygen and a hydrogen from a side chain by reduction. Ephedrine and methamphetamine most certainly DO NOT look the same under a mass spectrometer; I imagine it’s quite easy to distinguish the peaks from one another. Did Reding’s editor basically make a pass on the science stuff?

Reding’s book relies heavily on a series of articles on the meth epidemic written by Steve Suo of the Portland Oregonian. (If you look in Suo’s articles, you’ll see that Reding basically reworded the somewhat-more-correct chemistry explanation from Suo’s article.) Reding and Suo’s larger point  is that (-)-pseudoephedrine does not generate CNS-active methamphetamine, and that Warner-Lambert (and subsequently, Pfizer) were not interested enough in the larger public health issues to spend the money to push (-)-psuedoephedrine through the FDA approval process when the enantiomer they had was already quite lucrative.

So now that we’ve had a laugh about bad chemistry explanations, a question for everyone: how easy is it to get (-)-pseudoephedrine? The companies in India contacted by Suo said that they could supply ton quantities, no problem. I’m skeptical, but not that skeptical. Anyone out there know about this?

By October 20, 2009 8 comments general chemistry

Wolfram|Alpha as a resource for chemistry basics

In honor of the ACS national meeting in DC, the WolframAlpha blog featured how to use their engine for chemistry. I won’t steal all their thunder so link is below.

Link: Wolfram|Alpha Chemistry 101

Mitch

By August 17, 2009 1 comment general chemistry

Cake From Lab Chemicals

The Nottingham crew that has brought the entertaining hair-stylings of Martyn Poliakoff with their series of Youtube videos on each element in the periodic table (periodicvideos.com) has celebrated its first birthday. In honor of the occasion they made a cake out of lab chemicals. The only non-hazardous labeled materials used were butter and eggs, which are impossible to find an appropriate lab substitute.

Although chemists don’t have a chemistry rock star, Youtube has made Martyn Poliakoff as close as we’ll get. Unless someone is bold enough to go the Paris Hilton route.

Safety Note: The cake baker, Samantha Tang, has no gloves on although she has a lovely accent and introduces me to a new interjection, “Pants!” In the background there are other lab workers without lab coats and their personal protective equipment.

Phil first covered the website earlier this year: The Periodic Table of Videos

Mitch

By June 22, 2009 1 comment fun, general chemistry