Melamine and cyanuric acid chemistry lesson

Via the Knight Science Journalism Tracker at MIT, I was directed to one of the best-written articles on melamine contamination of pet food and animal feed.

David Brown at the Washington Post is the guilty party whose article appeared Monday. Brown does a terrific job of explaining how the modestly toxic substance, melamine, can cause renal failure when combined with cyanuric acid. Not widely reported in the press is the fact that cyanuric acid, another nitrogen-rich compound, has also been found to contaminate some wheat gluten and wheat flour from China.

For example, here is the most concise description of renal tubular concentration and solute solubility product that I have ever read:

The purpose of urine is to concentrate water-soluble waste products and to keep them dissolved. But water's dissolving power has its limits. Melamine and other chemicals can reach concentrations that exceed those limits. When the water can't hold any more, the chemical substance begins to form crystals.

Brown takes a story that has been beaten to death and sheds new light on the facts in a highly engaging manner. Heck, he even taught me that cyanuric acid is used as a chlorine stabilizer in pool chemicals.

The article is a superb piece of scientific journalism. Don't take my word for it; read it for yourself.

More like this

The problem of melamine in the food chain continues to be discussed, so we thought we'd do a follow-up of our earlier post. The mechanism whereby melamine, or melamine plus some other factor, or something else entirely is the cause of pet deaths remains unclear. The latest theory is that a co-…
This morning's post from Molecule of the Day reminds me to ask "cyanuric acid question." With the recent adulterations with melamine of Chinese milk and milk products (like White Rabbit chocolates) and foods with other milk-derived ingredients, we wonder if we will ultimately hear that a compound…
Lots of us knew melamine as a heat resistant plastic polymer found in kitchen items, like plastic plates. Despite its reputation for heat resistance it would melt in an oven, although it doesn't catch fire. It is used in a lot of other places: floor tiles, white boards, fabrics, filters, even the…
Last year, we were fretting about melamine contamination in foods from China. Again, this week, it's happening - melamine was put into milk by some unscrupulous vendors. The idea here is that melamine is high in nitrogen and cheap. An easy way to get an idea of how much protein is in something is…

Thanks for this pointer.

The current round of press stories _still_ is only mentioning melamine, not the combined effect nor the fact that other chemicals are also used to adulterate food.

And I really used to like those Chinese milk candies, too.

How long has this stuff been in them?

By Hank Roberts (not verified) on 24 Sep 2008 #permalink