Natural heavy water apparently is mostly HDO, as I suspected. Isotopic Composition of Water gives the HDO proportion of sea water as 320 ppm. Since deuterium makes up roughly 150 per million of hydrogen atoms, there wouldn’t be much left over to make D2O. If the isotopes of hydrogen react at random with oxygen, we would expect that by chance only about 25 in one billion water molecules would be D2O.
The site also says C-D (carbon-deuterium) bonds are much stronger than C-H bonds, which surprised me. Also amphetamines “are more readily transported into the brain in the deuterated form.”
Work is the curse of the drinking classes. (Oscar Wilde)
This ballpark figure is pretty accurate! if anyone’s interested, the term used here is kinetic isotope effect and involves the different rate at which molecules react (as a ratio) when the important site has either X-H or X-D (or even X-T). Commonly, the ‘H’ rates are observed between 1 and 7 times the rate of the ‘D’ molecule. The highest observed was k(H)/k(D) = 24, but this was probably due to tunnelling. k(H)/k(T) = 79 for the same reaction.
Hey, thanks for the info post adjacent to the one I quoted. Sorry to nit-pick but, by my calculations $50 / 100g = $0.50 per gram. That’s 10 cents higher than the price I quoted of 40 cents per gram (actually 1kg for $424.50 also in Aldrich). By chemical standards, that’s not very expensive, but let’s look at what that would do to the price of a bottle of lotion. I looked at several bottles of lotion here at work, and the average had about 15 ingredients, and all of them had water listed as the primary ingredient. Let’s assume a 16 oz bottle of lotion with the lotion’s density being that of water (1g/mL). Let’s also assume that the D20 makes up 10% of the lotion.
10% of 16 oz (454g) = 45.4g
45g @ $0.40/g = $18
Basically, we’ve just added the whole $18 to the cost of the lotion because, had we used H2O, the cost of the water would have been pennies.