Ricin

It's a toxicology marathon this week, today we're looking at ricin. Ricin's rise to fame was catalysed by the assassination of Georgi Markov. Markov's mysterious death was discovered to be due to a pellet of ricin injected into his leg by a contraption in an umbrella. Ricin is especially deadly as it takes a comparatively long time to kill compared to the other poisons featured.

Name: Ricin

Structure: Glycoprotein

Effect on Victim: Ricin has serious effects but not ones immediately seen as life threatening. Ricin's symptoms include dizziness, a high temperature, vomiting and diarrhoea. However Ricin can cause death in just 24 hours. Ricin works by inhibiting the cell's ability to synthesis proteins from amino acids according to the mRNA received in the ribosomes. These proteins are essential and without them the body quickly dies.

Lethal Dose: The lethal dose is just 22 micrograms per kilogram if ricin is injected, however if it is taken orally the lethal dose is much higher, around 30 milligrams per kilogram.

This is a photomicrograph of the pellet found in Markov's leg. The pellet held less than 500mg of ricin, a testament to it's lethality!

Diagnosis: The symptoms are akin to a very severe, incredibly quick working septicaemia. Since much more ricin is required to kill orally than by injection any puncture wounds should arouse suspicion. Ricin can be made from castor oil, so large quantities of that is also a clue. Ricin can be identified by mass spectrometry in a sample of tissue so it can be detected in human tissue. This works by detection of selected marker peptides specific for ricin (Ricin is composed of two protein chains); T5, T7, T11, T12, and T13 from the A-chain and T3, T5, T14, T19, and T20 from the B-chain.

You may remember me warning you to steer clear of apricot kernels, due to the possibility of cyanide poisoning, well castor seeds are a very similar case. Thanks for reading, over and out!

Carbon Monoxide

Another addition to the poison's catalogue, this time in the form of one of the most feared gases around. Carbon monoxide is so notorious due to the fact it's not only easily produced but is a colourless, odourless gas. I'm going to go through how Carbon Monoxide works and how to diagnose a carbon monoxide poisoning.

Carbon Monoxide's not a gas to mess around with!

Name: Carbon Monoxide

Formula: CO

Effect on Victim: Carbon Monoxide's effects appear relatively tame compared to the other poisons I've covered. Acute poison monoxide poisoning doesn't cause any vomiting, hair loss, convulsions or paralysis. What Carbon Monoxide does is more subtle. Acute Carbon Monoxide poisoning results in a headache, followed by possible nausea, then dizziness, breathlessness. If the person hasn't managed to escape the poison by now they'll collapse and lose consciousness. Once this happens they'll soon die due to mass cell death. Carbon Monoxide works by preferentially binding to haemoglobin over oxygen. This means that the pp (partial pressure) of Oxygen becomes extremely low in the blood. This makes it extremely difficult for cells in the body to take up the oxygen from the blood which they need for respiration to produce ATP. Carbon Monoxide is commonly used in suicides as the loss of consciousness means it is relatively painless.

Lethal Dose: 0.16% concentration in air will kill in less than two hours, however a 1.28% concentration can kill in as little as 3 minutes.

Diagnosis: Carbon Monoxide has one very distinctive calling sign which will alert you immediately to poisoning. This is the rosy colour it induces in the victim. Carbon Monoxide poisoning causes a bright, cherry pink which persists long after death. This can be confirmed by a blood test to see the levels of CO in the blood. On average a Carbon Monoxide poisoning victim will have a CO% saturation of the haemoglobin of 60% . You must factor into your analysis that smokers already have a Carbon Monoxide blood level of around 8-12% . Women, children and old people will also general have a lower lethal level.

There's the quick guide to carbon monoxide. Hopefully after this you'll see the reason for the drive for everyone to fit Carbon Monoxide detectors. Just remember cherry coloured skin is bad news. Over and out, as ever any feedback is welcome, thanks for reading!

Thallium

We're back to toxicology today.Thallium has a short but extremely notorious history, Thallium is a scarily effective poison. Only discovered in the 18th century, thallium has become one of the most feared poisons.

Name: Thallium, usually used as a poison in the compound thallium (I) Sulphate

Chemical formula: Ti, usually Ti2SO4

Effect on Victim: Thallium is an extremely toxic element, it's shocking that it saw so much use in the cosmetics industry (a surprisingly common trait among poisons). Thallium (I) compounds are highly soluble so readily absorbed through the skin, even touching Thallium is dangerous. Thallium has been popular as a poison not only because it is so readily absorbed by the body due (due to it's similar structure to potassium which the body needs) but also because it is completely odourless and tasteless, it's undetectable by nose, eye or tongue in almost any drink. Once inside the body Thallium works similarly to serious pneumonia. Acute cyanide poisoning induces nausea, vomiting, shortness of breath and death after about 30 hours. Thallium however displays a far more distinctive symptom when administered in gradual doses, alopecia. Thallium is actually causes hair loss with amazing rapidity, which is why it was used in the cosmetics industry. Thallium actually kills by entering the cells in the place of potassium, through potassium-sodium pumps on the cell's surface. once in the cell, where potassium helps maintain fluid balance in the cell and and feeds nerve cells, thallium disrupts chemical reactions, destroying cells ability to function correctly. Thallium spreads so efficiently that this effect soon becomes body wide.

Lethal Dose: 15-20 mg/kg of body mass

Diagnosis: Thallium gets it's name from the trademark green it exhibits in both a flame test and a spectroscopy test. Suspicions should be aroused by the hair loss associated with Thallium. Confirming these suspicions requires only a spectroscope test of the tissue. Thallium will display a distinctive bright green line.

This is a uniquely bright and vivid green.

You acquire the sample for the test through quite a delicate chemical reaction:

1. Grind down sample of tissue

2. Add nitric acid in excess to the tissue in a flask and leave for an hour

3. Place the flask in a steam bath for 2 hours (until tissue has completely dissolved).

4. Cool and filter solution through glass wool. Place resultant solution over an open flam.

5. Carefully add Sulphuric Acid to the heated solution (acids are much more corrosive when hot).

6. Leave the resultant sludge-like solution to settle down and then slowly trickle nitric acid into it. You should observe this colour change:

 red -> yellow -> colourless

When the solution is completely colourless it is ready. 

There's your basic guide to the analysis of thallium. Thallium is potentially hard to detect due to how similar it is to pneumonia in some respects, however there are warning signs. Just remember to look out for green tinted urine in acute poisoning cases and hair loss in gradual ones. Once again thanks for reading and feel free to comment with suggestions, criticisms, ideas or opinions. Over and out!