Poison Chemistry

Chemistry Blog #3: The Chemistry of Poison

Kathryn Ahearne


Two of the most common poisons that have been used throughout history to kill poeple are Cyanide and Arsenic. Both of these poisons are used less today, however, due to advancements in science and chemistry that we have made that make it possible to detect Cyanide and Arsenic poisoning in a person as well as reverse its effects on the body. Although there are many similarities in the history and effects of these poisons, there are also many differences between the two.

Cyanide, also known as the polyatomic ion CN is one of the deadliest poisons known to man and has been used for centuries as a method to kill people and animals.  Cyanide was first identified in 1782 by the chemist Scheele and has since been used for a variety of reasons including rat poison and pest control as well as chemical warfare in WWI. The seeds of many fruits contain a substance known as amygdalin which, when it comes into contact with stomach acid produces cyanide. When someone ingests cyanide, it inhibits the cytochrome oxidase enzyme, which then prevents the body’s cells from using oxygen. The effects of this include: Dizziness and headache, nausea and vomiting, rapid breathing and heart rate, low blood pressure, loss of consciousness, respiratory failure, and then convulsions and death. The effects of cyanide can be somewhat reversed through compounds of nitrite which remove the cyanide from cytochrome oxidase, however, cyanide is a very fast acting poison and often the effects of it are too severe for doctors to help the patient by the time they get to the doctor.

Arsenic is another poison that has been around for a very long time. White arsenic was used by many poisoners throughout history and has also been nicknamed, “The King of Poisons.” There are even documents of ancient Greeks and Romans using arsenic as poison in myths and stories. During the 17th and 18th centuries arsenic was used very often as a poison as well until advancements in chemistry made it easier to test for arsenic poisoning. The chemical formula for arsenic is As2O3 and its technical name is Arsenic (III) Oxide. In order to test for Arsenic poison, the Marsh Test is used. In this test, a reaction between the sample, zinc and acid is performed. If the sample contains arsenic, arsenic gas is formed when this reaction takes place. Then, upon cooling, scientists look for a silver-black layer of deposit to form. More recently, scientists have developed methods of detection involving spectroscopy that are now used more frequently. The effects of arsenic poison include headache, discoloration of nails, vomiting and metallic taste, breath smells of garlic, stomach pain and diarrhea, hair loss, convulsions, coma, and death. Arsenic interferes with cell enzymes as well as respiration and mitosis which then causes all of the above symptoms to occur.

These are very interesting topics to compare due to how similar they are in their history and use. Both were used as rat poison at some point, both have been used as poisons for a very long time and both of them are seen less today due to the advancements in medicine and chemistry we have made that allow for detection and reversal of the effects of the poison. Another interesting topic of comparison to these two articles about poison is the use of drugs and alcohol by people in the world and the effects that these drugs have on individuals’ bodies. For example, alcohol, which is used by individuals to feel drunk, affects the body in certain ways based on its chemical makeup, which is similar to the way that poisons affect the body based  on their chemical makeup. The chemical present in alcohol is ethanol, or C2H6O, which limits the actions of neurotransmitters in the brain. It is interesting that many of the side effects of these drugs and poisons are the same. For example, almost all of them include headache and stomach ache or vomiting. This is perhaps because these are two of the bodies primary responses to poison or unwanted substances in the body and mind.


Chemistry Matters

Recently I watched some presentations at the Chemistry Matters Symposium and I learned a lot about how chemistry relates to our everyday lives. Chemistry is a very important topic that is intertwined in some aspect of everything we do. How much Chemistry is involved in what we do depends more on the way we think about it than on what we are actually doing. Everything in the world around us functions on the basis of science and chemistry is one category of science that is very important in understanding the world. Throughout this symposium, I really started to notice how much the different sciences are intertwined and how much the lines between these categories are blurred when we are talking about the situations of our everyday lives.

Some of the presentations that I watched at the Chemistry Matters Symposium did a very good job of helping me see just how important chemistry is. One of these was the presentation about Chemistry in Art, specifically looking at chemistry in ceramics. As someone who is thinking about minoring in art, I found this topic very intriguing and enjoyed learning more about how chemistry relates to it. I have taken a ceramics course in the past and while we did go over some of the ways that chemistry is involved in it, I hadn’t realized before this presentation just how important it is. Everything that isn’t the actually molding of the pottery is essentially based on the ceramicists understanding of chemicals and their properties. The part of this process that  has always interested me when I did ceramics in the past is the glazing process. I always loved glazing because you really never know how it will turn out when it goes through the extreme heat of the kiln. What you painted on the ceramic piece looks completely different from what comes out of the kiln and the only way for you to know what color or texture it will be is by knowing what chemicals are in the clay. For example, if there is copper in the glaze, it usually turns out blue or green. Watching this presentation, however, I learned that when the piece goes in the kiln, an oxidation reduction reaction occurs which is what causes the glaze to turn out the way it does. In the redox reaction that takes place, the metal that is present in the glaze (such as Copper) is reduced and the Carbon or the Carbon Monoxide that comes from combustion is oxidized.

Another presentation that was very interesting to me was the one about Coffee. As someone who drinks coffee every day and has done this since 5th grade I found this topic to be very relevant to my life and the presenter did a very good job of keeping the audience engaged and attempting to keep the topic relevant to everyone in the class, even those who don’t drink coffee. I think that this is an important part of the presenter’s job, to focus their attention on the entire audience, rather than only those who directly associate themselves with the topic. As it turns out, coffee is actually the America’s leading source of antioxidants, which I found very interesting. I also learned that caffeine is another word for 1,3,7-trimethylxanthine or C8H10N4O2. I love the way coffee tastes and smells, but before this I thought the only benefit to drinking coffee was the caffeine boost it gave me every morning. Now, I know that there are also health benefits of coffee. These health benefits are mainly based on the antioxidants present in coffee known as chlorogenic acids which protect our body’s cells from what are known as free radicals. Free radicals attack DNA and have been linked, in the past, to things like Alzheimer’s disease, cancer, and diabetes. Knowing this makes me feel much better about my morning cup of coffee and I will definitely report this back to my family of daily coffee drinkers.

The other presentation that I thought was very interesting and very well done was about making candy. This topic is very easy for an audience to relate to as almost everyone likes candy or at least enjoyed it as a child. This presenter focused mainly on making rock candy as she found this was an interesting part of the article. I thought that this choice was well executed because it meant that she was presenting about the aspect of the article that she found most interesting which made her more engaged in the presentation. It also meant that she was dealing with a smaller portion to explain, making it easier for the audience to understand as the presentations were limited to only 3-5 minutes. Many of the presenters attempted to explain every little detail of their topic which only resulted in a very confused and uninterested audience. Personally, I like the way Rock candy looks more that it tastes, but the methods used to make it are very interesting to me. To make rock candy, you melt sugar down to a syrup and . The way that any candy looks is based on the cooling process and the way that the sugar molecules arrange themselves in certain patterns. With rock candy, you leave the sugar to cool allowing the sugar crystals to form on their own, which creates the rock-like structure. If you were making something like fudge, however, you would stir the syrup as it is cooling to break up the crystals so they do not get too big.

Overall, at the Chemistry Matters Symposium, I learned so many different things about how my life is based on science and how we explain the world specifically through chemistry. I hope that you learned a little something from my reflection of the symposium and I hope that I have now inspired you to learn a little more about how chemistry is relevant to your lives.

“Chemical Free”

Throughout the world today, different shops and companies are trying to sell to a more modern world, a world that reads articles and watches television shows warning them about the dangers of “chemicals” and “inorganic” products, the danger of pesticides and the willingness of big corporations to set their values to the side to make an extra buck. Commercials and advertisements are now seeing an opportunity to take advantage of the scared and ignorant consumer, checking the labels of their products to make sure they are “chemical free”. What exactly does this mean? Chemical free. free of the very things that make up our own bodies? Free of the chemicals that create the world around us? I guess the concept of a product that is “Chemical free” just doesn’t appeal to me in the same way it does for so many other consumers. I would rather have a product that actually exists. So as i walked through the isle of CVS today and saw at the Burt’s Bees sunscreen that read “Chemical free” I did not stop to look any further and i certainly didn’t pick it up to put it in my basket.

I suppose the company Burt’s Bees was not trying to falsely claim the impossible, but rather put the idea of a product that was not free of chemicals into the mind of the customer. As a customer walks through the aisle and sees the label that reads “chemical free,” they think to themselves what products that are not chemical free must be made of. A distinction they had never once thought of suddenly comes into question. What if all of the other sunscreens they own have chemicals in them? what if every other cosmetic and lotion also have chemicals. Now they have to feel guilty about buying anything other than the products labelled “chemical free”, thereby creating a consumer that will likely come back to the company that steered them towards the light of a healthier, “chemical free” life.

By claiming their product is free of chemicals, companies like burt’s bees are creating a world that is scared of something that they have simply created as a marketing strategy. Well, I am here to inform you, my readers, that chemical free products, from a chemist’s point of view, do not exist. Are there some products that probably contain materials that could potentially harm you or be less healthy? sure. but the whole idea of a product that is chemical free does not exist because the entire world around us is made of chemicals. Everyone and everything contains chemicals by the definition of the word. So next time you see that burt’s bees sunscreen in the aisle, don’t feel guilty for what you own or feel like you need to change your life. instead, just look at what’s in it. Why are they claiming this product is better? look into the products you buy for yourself. Do not let companies and advertisements create the labels for you.

burts bees chemical free