Question

In the movie Arsenic and Old Lace, two elderly sisters poisoned their gentlemen roomers with elderberry wine that contained arsenic. (The wine also contained strychnine and a pinch of cyanide, but let’s ignore those.) They got no help from their nephew, played by Cary Grant; but then, he knew nothing of dose-response curves. Since you do, what advice could you give the elderly sisters to make sure the wine was lethal without wasting a lot of arsenic? (Death in the hands of more recent entertainers like Slipknot has become less chemical and much more serious. Dose-response curves no longer seem relevant.)

Answer 1

Answer: An ACUTE FATAL DOSE of Arsenic (oof the form of As₂O₃) is in the range of 2-20mg/kg body weight/day.

So a healthy person weighing aroung 160 lbs can die witha dose of 0.192gm to 1.92gm of Arsenic Trioxide. (Arsenic Trioxide is probably the most commonly available Arsenic compound).

Considering the high density of the oxide, less than 1/8 of a tea spoon can be fatal.

It has been reported that the trivalent Arsenic compounds, Arsenites, are much more toxic than the pentavalent compounds, arsenates.

To make it even more lethal, if this dose is given in an alkaline media, as it forms extremely toxic arsinates,

AsO₂^-1 ions.

So, though its is illegal to suggest, the lethal effect of arsenic can be obtained if given with the alkaline media, i.e. the drink containing high alocohal percentage.