2009

Acetonitrile

Analytical chemistry labs in drug companies, academic research groups, and forensic science labs had a rough time of it in 2009, although it’s safe to say that the rest of the world didn’t notice. One of the most common solvents for reverse-phase chromatography is acetonitrile (a two-carbon compound consisting of a methyl group attached to a carbon-nitrogen triple bond). Its popularity is understandable: it mixes with water in any concentration; it dissolves a wide range of less polar organic molecules; and it’s unreactive, relatively nontoxic, and easy to evaporate. But these advantages are all for nothing if you can’t get enough acetonitrile, and for several months in late 2008 and well into 2009 there was an unprecedented shortage. Prices began creeping up, then skyrocketed, and then suppliers began calling their customers to say that many orders were just not going to be filled. Methanol could be used as a substitute in some cases but not all.

Several factors caused this situation. Factories in China that produced the solvent were shut down to improve the air quality for the Beijing Summer Olympics, and this put a crimp in the worldwide supply. A U.S. facility on the Gulf Coast was affected by Hurricane Ike. But the general problem was the global economic slowdown. Most of the world’s acetonitrile comes as a by-product of the process used to make another chemical, acrylonitrile, which is used in many industrial polymers. Reduced demand for auto parts and other high-volume items caused many acrylonitrile plants to slow or shut down production, and the acetonitrile supply accordingly began to dry up as a side effect.

There are several other ways to make the solvent on an industrial scale, but no one had ever bothered, since recovering it from acrylonitrile plants was always cheaper. A few companies sprang up to try out these alternative routes during the shortage, but the gradual recovery of the acrylonitrile market (and the accompanying drop in acetonitrile prices) seems to have put these methods back on the shelf. Unless, of course, another banking crisis makes the HPLC systems stop running again . . .

Heavy fog and haze at Tiananmen Square in Beijing, February 2013. The Chinese government’s effort to avoid such scenes during the 2008 Summer Olympics was one of the factors in the sudden and unexpected short supply of acetonitrile.