Need help from Dope chemists, poisoners

So I’m writing a bit for an RPG I’m running, and I need a bit of help. Here’s what I want to happen: a woman kills her husband by replacing the contents of one or two of his prescription gelatin capsules with some kind of poison, and I’m looking for a poison that fits.

The woman is not a chemist and doesn’t have access to anything special, so it has to be something fairly simple, something you could maybe look up on the internet or learn through gardening. My main problem is that one of the players is actually a chemist, and really knows her stuff. This needs to be as real as possible, or she’ll call me on it.

It needs to be a small enough lethal dose that it can fit in a capsule or two, and it should kill fairly quickly. You can’t get enough normal household chemicals in a little pill for a lethal dose, and things like poisonous mushrooms tend to take too long and can be treated fairly easily.

My first thought was that she could extract pure nicotine out of chewing tobacco, but that gives you a wet sludge, and I don’t think that would work in gelatin capsules. But what if you coated the inside of the pills with a thin layer of wax? Would that work? How long would it stay deadly?

Is it possible to extract the poison (cyanide?) out of apple seeds? Can you get powdered cyanide out of them? Enough to actually kill her husband in one go?

What about other poisonous plants, like pokeberry, or something decorative like lily of the valley? How do you get the poisons out of plants?

Are there any normal kitchen spices that become dangerous in larger pure doses?

What about two things that become dangerous when they’re mixed? Is there anything that would work that way?

Well, you’re going to want to find something with an oral LD50 below 10 mg/kg. Translated to humans, that means if your 100 kg victim eats 1 gram of poison they’ll probably die. Off the top of my head and a bit of googling I can’t think of any common household chemicals that are toxic enough. Cyanide obviously fits the bill, but it’s not something that you can come by easily.

Any reason why she couldn’t offer him a nice bottle of methanol?

How much methanol would he have to take at once to kill him? Does it taste funny?

I kinda would like it to be in a pill.

What about Belladonna or Datura?

I’m no chemist and my poisoning exploits have been greatly exaggerated, but the two things that jump to mind are Ricin and Botulinum toxin. I’m pretty sure they are toxic enough, and theoretically would be obtainable without too much trouble (castor beans and spoiled food), but I’m not sure how easy it would be to extract.

According to Wiki…“fatal dose is typically 100–125 mL (4 fl oz)” And apparently it’s indistinguishable from ethanol by taste.

Methanol isn’t anywhere near toxic enough – oral LD50 is in the ballpark of 10 g/kg. Your victim would have to drink half a liter to be in any short term danger…

Botulinum would definitely do the trick, but culturing botulism takes a decent amount of expertise and specialized equipment (it won’t grow in the presence of oxygen). I suppose the home canner could deliberately do everything possible to get optimal botulism growth, wait months or years for the scariest, bulgiest looking can, and hope there’s enough botulism in there. They wouldn’t be able to extract the botulinum toxin without a good bit of biochemical expertise.

Even a simple culture or extraction is going to be complicated to someone without a degree and the proper equipment, so I think you have to rule out anything the lady could make unless she knows people who will do it for her.

Speaking of finding things like that… are we talking an RPG set in the modern age? If so, I don’t think finding exotic stuff is all that hard. Put up a post like this on a forum to get a dozen good suggestions for lethal things that would fit in a pill. Then put up another post somewhere else asking how such things could be legally obtained (for example, ask “What industries use cyanide?”). Then it’s just a matter of bribing someone, stealing something, etc.

I did a lot of role-playing back in the day and there’s another technique you might use. My players liked it when used reasonably. Put your chemist friend on the spot. When the characters learn of the death and the coroner describes the death, point to the chemist in the group and say “Tell us what the coroner says! Pick a poison that can kill with less than 1 mg, and describe to us the side effects observable in the corpse.” Now the chemist person only has themselves to blame if their choice is inappropriate. More importantly, they got a chance to show off their expertise, which is probably the reason they’d have tried to argue with you in the first place.

Would any commercially-available rat poisons be deadly to humans in the appropriate dose?

Alternately, the fact that the husband is taking pills regularly implies that he has some existing health condition, that might make him more vulnerable to some substances (even to some substances that wouldn’t be dangerous to a healthy individual). Would something like that work?

A normal size capsule shell can hold about 500mg of lactose powder. If you are filling a capsule from his prescription, then that means he takes medication regularly. Could you perhaps have him on some other medication that she could crush the tablets and put them in the capsule shells? Perhaps something like Levothyroxine (Synthroid)? Levothyroxine overdose would put the person into a Thyroid storm, though I don’t know how long it would take to actually kill them.

Being not a chemist, I’d head for the lawn and garden store and pick up a jar of pesticide. Some of them are still pretty hard on humans. Even better, I could scrape the remaining organophosphate from a jar of insecticide my elderly neighbor has kept in his garage since the late 60’s. Death wouldn’t be guaranteed, but the suspense while waiting would be delightful!

See that’s just it, it apparently depends on the poison. When I first started looking stuff up online, simple searches got me an easy method to extract the nicotine from normal chewing tobacco (soak in water, strain out tobacco, boil water, sludge at the bottom is close to pure nicotine). Pure nicotine has a really low fatal dose, some sites claiming that if a person got a high enough dose it could kill them in minutes. There’s gotta be other stuff like that out there.

Hmm. That could work. Ok then, what industries use cyanide? Is it possible to just buy some cyanide without having a permit or whatever?

Yeah, that sounds good. So, what conditions would make someone vulnerable to a substance that isn’t normally dangerous? I’m lactose intolerant, and as much as I wish it would be while I’m on the toilet, it’s not lethal.

How about foxglove? The stuff is certainly potent enough, and I think you’d be OK with simply drying and crushing the most potent parts of the plant and putting them into the capsules…

I think the pesticide is going to be your best bet. Paraoxon is the active metabolite from Parathion which may be found in old insecticides.

You might also do OK with headlice-shampoo, or extracting nicotine from skin patches with Everclear, but I don’t think either option’d be likely to occur to a non-chemist.
I wonder how toxic ‘tough actin tinactin’ might be when ingested?

Certain nut and shellfish allergies can be really bad, but I’m not sure they can be counted on to necessarily produce a fatal reaction.

Whoa:

That’s awsome! Now I need find out how much he would have to consume for it to be fatal.

Here’s a start from Wikipedia: http://en.wikipedia.org/wiki/Cyanide#Applications Looks like gold mining and nylon production are two potentially good candidates for getting some. A permit/license of some sort would be required.