11.24.09
Death by Isotope Effect
So the other day my teacher was riffing about an idea she had for the perfect murder. She called it death by isotope effect, and it involved freezing deuterium oxide, and placing it in an alcoholic beverage. Now deuterium oxide, also known as heavy water, is simply H20 but instead of hydrogen nucleus containing only one proton, it contains a neutron as well, giving it double the weight without effecting the charge. Since the oxygen molecule is far heavier than both the hydrogens this ends up being only a 1/9th increase in weight over regular water but does lead to it’s name.
Her idea was that, although the heavy water ice cubes would sink in regular water, they would float in alcohol, so you would be able to slip them inconspicuously into someones drink and down goes the heavy water with all the booze. The heavy water would never show up in a toxicology report, and the crime would remain unsolved. (48 percent of murders each year in the US remain unsolved anyways, so this seems like being over cautious)
So what makes heavy water toxic? Well the added mass in the nucleus of the hydrogens makes for a slightly shorter, slightly stronger bond than the normal H20. Since biological processes depend heavily on this bond strength being the same as it has been for the last say 2 billion years, it makes cell divisions necessary in the building of certain proteins rather difficult. This eventually leads to tissue breakdown and death.
So why does the MSDS rate deutrium oxide as nonhazardous? Well the amount of deutrium oxide needed to actually make this biological change happen is quite large. Some estimates say that the isotope would need to make up half the water in the body. Being that we are about 60 percent water, I will need to ingest about 42 pounds of this stuff. Being that the going price of heavy water is about a dollar per gram, this puts the price of my execution at around 20 thousand dollars. And for the average person this would be quite an investment and I must say a little suspicious, perhaps even more suspicious than the old bloody knife in the dumpster, or better yet the melting murder weapon from that episode of Matlock, the knifecicle.


