Recent Analysis Shows Modifications Made to Lavoisier Painting

 

They say that history is written by the victors. In Antoine Lavoisier’s case, he was not one of them. It’s a well-known fact that he was denounced and guillotined in 1794 for being a wealthy tax collector, during the French Revolution. He was, of course, also a famous and brilliant chemist, whose influence in the field cannot be understated (earning him the moniker ‘the father of modern chemistry”). Recent analysis of a famous 1788 painting of him and his wife, Marie-Anne, shows that the painting was modified to show less of his wealth and more of his science. 

Dorothy Mahon, a conservator at The Metropolitan Museum of Art, noticed some oddities in the painting while carefully removing a degraded layer of varnish. Cracks in the paint seemed to show other colors beneath, and tiny cracks on the tablecloth seemed to reveal that the final layer of paint was a later addition. This prompted further analysis. 

 

Fig. 1: Signs of the original painting showing through the top coating

Firstly, infrared ray reflectography was utilized to reveal what lay beneath the painting’s surface. IRR is a technique where infrared light is cast on the painting, which can pass through the surface layer. By measuring the infrared light that’s reflected by different areas of the painting, things underneath the surface can be seen. The IRR applied to this painting showed several things -- the initial sketch that was painted over being modified several times, changes in facial expressions, a wastepaper basket that was removed from the final product. Most interestingly, it revealed several discontinuities that weren’t as easily explained by the painting process -- an elaborate table under the tablecloth, a blurry object on the table, a strange smudge on Marie-Anne’s head. 

This prompted further analysis. For a more accurate view of what lay beneath, macro X-ray fluorescence mapping was utilized. This technique uses X-rays to detect the elements in a sample. The X-rays bombard the sample, and the emitted energy is measured. These emissions are cross-referenced with atomic spectral lines to determine the composition. Once the elements in a sample are known, it can be inferred what pigments were used to color the painting, and it can thus be determined what the painting looks like under the surface. To help with determining which pigments were used, seven small paint samples were taken from the painting and analyzed. 

The macro X-ray fluorescence elucidated the changes to the painting. Most prominently, Marie-Anne originally had a large flamboyant hat, with ribbons and feathers. The table was originally a lavishly gilded wood, before it was covered in the red tablecloth seen today. Some of the scientific instruments in the painting were added later, and Lavoisier was originally wearing a red mantle that was removed. All in all, the painting was modified to show much less wealth, and instead focus on Lavoisier’s scientific pursuits. 

 

Fig 2: The image as it is seen now, under IRR imaging, and reconstructed after MA-XRF analysis

The painting has since been revarnished and sits at The Met, the same as it always has. It looks the same as it did before, of course, showing Lavoisier and his wife as the great scientific couple they always were. But it’s worth thinking about, now, how carefully that image was chosen to depict them as it does. 

References:

Blakemore, Erin. "Tech Uncovers Changes to Portrait of a Chemist-Couple, Victims of Reign of

    Terror." The Washington Post, 11 Sept. 2021, www.washingtonpost.com/science/

    art-restoration-science-met-lavoisier/2021/09/10/f2100e0a-10dc-11ec-9cb6-bf9351a25799_story.html.

    Accessed 26 Oct. 2021.

Centeno, Silvia A., et al. “Discovering the Evolution of Jacques-Louis David’s Portrait of Antoine-Laurent and Marie-Anne Pierrette Paulze Lavoisier.” Heritage Science, vol. 9, no. 1, Springer Science and Business Media LLC, 30 Aug. 2021. Crossref, doi:10.1186/s40494-021-00551-y. 

Centeno, Sylvia A., et al. "Refashioning the Lavoisiers." The Metropolitan Museum of Art, 1 Sept.

    2021, www.metmuseum.org/perspectives/articles/2021/9/david-lavoisier-conservation. Accessed 26

    Oct. 2021.

Pigs to The Rescue!

     

    Over one hundred thousand people within the United States are on the national transplant waiting list desperately in need of a kidney. With this shortage comes about twelve deaths each day. Scientists and doctors have been trying to find out an ethical and effective way to solve this organ shortage. As of October 22, 2021, surgeons in New York City have successfully attached a pig kidney to a human that wasn’t immediately rejected by the host human. This is a huge step in modern medicine to help those who die waiting for an organ they need. This article was chosen because I signed up to be an organ donor when I got my license and believe that other people should have the chance at a second life. 

According to Science News, the article titled, “What does the first successful test of a pig-to-human kidney transplant mean?” walks the reader through the scientific and moral considerations that come with this medical breakthrough (Lambert). The process of xenotransplantation describes any procedure that involves transplantation into a human from a nonhuman source (Center for Biologics Evaluation and Research). Pigs were chosen due to how anatomically similar their organs are to humans as they have all the same thoracic and abdominal organs. They also are able to be bred in a highly controlled manner, which is important if mass production of these organs will be necessary in the near future. 

The immediate reaction that occurs following a xenotransplantation is called a hyperacute rejection. It can be described as the most severe and violent immunological reaction that occurs within the first 24 hours that results in loss of function and death of the organ (Hyperacute graft rejection). In recent years, scientists have discovered that this aggressive immune response is brought on by antibodies that detect a specific sugar molecule that dots pig blood vessels, called alpha-galactose or alpha-gal for short. This sugar molecule is also responsible for some allergic reactions to red meat. Scientists figured out how to disable the pig gene that is responsible for producing this sugar in the early 2000s but only recently have produced successful results.  

Figure 1: Structure of Alpha-1, 3-galactose

Alpha-1, 3-galactose is a carbohydrate found in most mammalian membranes except for humans and primates. While there have been some known breakthroughs when it comes to Alpha-gal syndrome (AGS), the mechanism of action for alpha-gal is still unclear and requires further research. It has been found that a bacterial alpha-galactosidase efficiently can remove linear alpha-gal ends from target molecules.

Figure 2: Stepwise process of xenotransplantation

The FDA has also recently approved altering the gene that produces alpha-gal for those who can’t eat red meat to produce a new “breed” of GalSafe pigs (Commissioner). These pigs are created by modifying the target gene (GLA) by eliminating gene expression in a pig embryo. This modified embryo is then implanted inside the surrogate sow who will deliver piglets with modified immune systems more compatible with humans. When the pig kidney is removed from the adult swine, the pig’s thymus is also removed with it and attached before attaching to the host human. This is an important step because the thymus gland can help educate the human’s immune system to recognize the kidney as part of the body. Lastly, the thymus-kidney system is surgically connected to the organ recipient on their thigh so that the doctors can oversee the kidney function outside of the body.

The ethical considerations when it comes to operating on humans in this manner is always going to be up for debate. The family of a woman who was pronounced brain dead but kept alive on a ventilator gave consent for this procedure to take place. The woman wanted to be an organ donor but in the state that she was in, was unable to donate her organs. The family believed that she would have approved of possibly giving the gift of humanity to other people in another way. The doctors attached a pig kidney with the absence of the alpha-gal sugar as well as its thymus gland to the woman and monitored normal kidney function. The kidney produced urine and showed other signs of normal functioning for 54 hours before the procedure was terminated due to guidance provided by ethics reviewers.

Sources

Center for Biologics Evaluation and Research. (2021, March 3). Xenotransplantation. U.S. Food and Drug Administration. Retrieved October 26, 2021, from https://www.fda.gov/vaccines-blood-biologics/xenotransplantation#:~:text=Xenotransplantation%2 0is%20any%20procedure%20that,nonhuman%20animal%20cells%2C%20tissues%20or. Commissioner, O. of the. (n.d.). FDA approves first-of-its-kind intentional genomic alteration in line of domestic pigs for both human food, potential therapeutic uses. U.S. Food and Drug Administration. Retrieved October 26, 2021, from https://www.fda.gov/news-events/press-announcements/fda-approves-first-its-kind-intentional-geno mic-alteration-line-domestic-pigs-both-human-food. Hyperacute graft rejection. Hyperacute Graft Rejection - an overview | ScienceDirect Topics. (2014). Retrieved October 26, 2021, from https://www.sciencedirect.com/topics/medicine-and-dentistry/hyperacute-graft-rejection#:~:text=H yperacute%20rejection%20refers%20to%20the,within%20a%20period%20of%20hours. Lambert, J. (2021, October 22). What does the first successful test of a pig-to-human kidney transplant mean? Science News. Retrieved October 26, 2021, from https://www.sciencenews.org/article/xenotransplantation-pig-human-kidney-transplant.

Carnivore in Disguise

                                                                                              Posted by Mallory Gehrer

Picture of the flower of Triantha occidentalis (1). 

Not every plant soaks up energy and nutrients from sunlight and soil. Sometimes plants can get a craving for meat, too. In the case of this flower, it’s habits of carnivory went unnoticed until just recently, likely due to the fact that it doesn’t quite look like the stereotypical carnivorous plant. This flower might look familiar to some as it is a species native to the west coast and pacific northwest. It even grows in city centers, being very resilient to urban life.

This species of false asphodel happens to snack on small insects, digesting their bodies for important nutrients instead of drawing it all from the soil. Carnivory in plants evolved as a way to live in nutrient poor soils. But how exactly did researchers from the University of British Columbia figure this out, and how does a plant even digest a bug anyways (2)? They used a little trick called nitrogen-15 tracing to first determine if the flower truly was a carnivore. If the flower got a majority of its nitrogen from bugs instead of the soil, then it technically would be carnivorous.

To measure and predict the amount of nitrogen passing through a plant, a type of Monte Carlo simulation is carried out (3) Using these models, they found that 64% of nitrogen came from bugs, which was consistent with other known carnivorous plants (4). One of the reasons this flower went unnoticed for so long was because the Triantha occidentalis uses a unique method to trap its prey. Small, sticky hairs cover the stems of the plant, and they secrete phosphatase, a common secretion in carnivorous plants that digests prey. Phosphatase removes phosphate groups from proteins, and other enzymatic secretions help the flower extract nitrogen and sulfur as well (5).

Sticky hairs on the stem of the Triantha occidentalis (2).

The Triantha occidentalis is so far the only flower that captures bugs on the stem, rather than in an insect trap. The researchers think that, like an insect trap, having small sticky hairs allows the species to trap small, non-pollinating bugs, while larger bugs and pollinators do not get trapped. Otherwise, the plant would be unlikely to spread without a pollinator. What digests the small bugs is phosphatase, an enzyme that cleaves phosphoric acids on larger substrates into phosphate ions and alcohols. It requires water to react, so it is a type of hydrolase.

 

By using these methods to track nutrient absorption and by identifying new types of bug-catching methods, researchers can find more types of carnivorous plants, and hopefully better understand the environmental conditions and mutations that lead plants to carnivory!

[1] Sweatt, B. (n.d.). Triantha occidentalis. Calflora Observation. Retrieved October 19, 2021, from https://www.calflora.org/entry/occdetail.html?seq_num=mu5941.

[2] Chambers, J. (2021, August 18). A well-known wildflower turns out to be a secret carnivore. Science News. Retrieved October 19, 2021, from https://www.sciencenews.org/article/wildflower-carnivore-plant-sticky-hair-insect-trap.

[3] Tobias, R., Huygens, D., Staelens, J., Müller, C., & Boeckx, P. (n.d.). Advances in N-15-tracing experiments: New Labelling and Data Analysis Approaches. CORE. Retrieved October 19, 2021, from https://core.ac.uk/display/55890295.

[4] Lin, Q., Ané, C., Givnish, T. J., & Graham, S. W. (2021, August 17). A new carnivorous plant lineage (Triantha) with a unique sticky-inflorescence trap. PNAS. Retrieved October 19, 2021, from https://www.pnas.org/content/118/33/e2022724118.

[5] UCSB Science Line. (n.d.). Retrieved October 19, 2021, from http://scienceline.ucsb.edu/getkey.php?key=4884. 

 

 Decomposition Art

While many artists choose traditional mediums like oil and acrylic paint, clay, or stone, Marcin Rusak chooses a unique medium, old plants. He takes nonliving organic matter and preserves it in his creative process. Rusak is inspired by his childhood, when he used to play among old greenhouses, and has fond memories of being among the plants. He also has motivation to conserve material, sourcing originally from local florists who were discarding old flowers. 

Rusak introduces us to some interesting chemistry. When plants die, they begin the process of decomposition, to return to more simple organic compounds that can then be reused in the environment. They begin to lose water, and small soluble carbon compounds leave with it. Plants break down into smaller pieces as bacteria step in to further decompose the organic matter. Some bacteria commonly involved in the process are Bacillus subtilis and Pseudomonas fluorescens, which are primarily found in the soil. The plant, with the help of microbes in the soil, begins to decompose into material called detritus, the kind of material you would commonly find on the ground in a forest. This is primarily made up of and structures we would recognize from plants.

Cellulose 

Hemicellulose

The first image above is the structure of cellulose, and the second is hemicellulose. As they are both polysaccharides, they are composed of sugars, covalently linked together. Their structures differ in which sugars are present, and which bonds are formed. The more complex the structure, and the more bonds in each polysaccharide, the more time they take to decompose.

In most of his art, Rusak is able to defy this process. The flowers are first dried in order to curtail decomposition. Creating a dry environment creates unfavorable conditions for decomposition by bacteria, and by processes in the plant itself. Additionally, removing the plants from an environment, like the soil, where decomposing bacteria are commonly found, decomposition processes cannot occur via these organisms. 

Furniture from Rusak’s collection, Perma. 

Another way that Rusak fends off decomposition is by encapsulating his plants in resin. Recently, his work with plants preserved in resin, especially his resin furniture has gained traction. The resin that Rusak uses is likely a casting resin, which is usually an epoxy (named for its epoxide group). 

General reaction scheme for epoxide resin. 

The final hardened material that’s seen in his furniture is originally two solutions, the resin and the hardener. The hardener, or curing agent, is usually a structure containing an active hydrogen, like the general reactant shown in the figure above (R-XH). The resin will be structurally similar to the second reactant, the epoxide. When mixed, a chemical reaction occurs that solidifies the mixture. In the general example above, the active hydrogen is able to react with the epoxide, breaking it open and producing a hydroxyl group. This reaction also relieves angle strain that was present in the epoxide, forming a more linear chain. Many formulas of resin and curing agents contain multiple reacting groups, which is key to solidifying the solution. The more bonds formed between the original molecules, the more crosslinked, and stable the material becomes.

Rusak now has a studio in Warsaw, Poland, which encompasses over 5,400 square feet, and his art will be featured soon in the states, at the Twenty First Gallery in New York. Rusak has a talent for reimagining what is decaying, and he uses it to create his art. The bacteria helping Rusak also have the same idea, to take existing organic compounds in the plants, and turn them into much more simple biological molecules that can be recycled in the future, or maybe, preserved in a resin chair.

References

Wallis, Stephen, and Rafal Milach. “A Designer Who Finds Beauty in Decay.” The New York Times, The New York Times, 12 Oct. 2021, https://www.nytimes.com/2021/10/12/t-magazine/marcin-rusak-plant-decay.html.

“Epoxy Resin.” Epoxy Resin - an Overview | ScienceDirect Topics, https://www.sciencedirect.com/topics/chemistry/epoxy-resin.

“Hemicellulose.” Hemicellulose - an Overview | ScienceDirect Topics, https://www.sciencedirect.com/topics/materials-science/hemicellulose.

“Cellulose.” Wikipedia, Wikimedia Foundation, 24 Aug. 2021, https://en.wikipedia.org/wiki/Cellulose#/media/File:Cellulose_Sessel.svg.

“Decomposition.” Wikipedia, Wikimedia Foundation, 29 Sept. 2021, https://en.wikipedia.org/wiki/Decomposition#Plant_decomposition.

Hydrogen with Two Bonds?

We have been taught all throughout school that hydrogen can only form one singular bond, what if I were to tell you that recently there was a major scientific discovery that found hydrogen binding to two different fluorine bonds. This information should absolutely blow your mind! This is written about in an article written by Emily Conover titled “This weird chemical bond acts like a mash-up of hydrogen and covalent bonds”. Hydrogen bonds are seen as weak electrical attractions rather than true chemical bonds. Covalent bonds are strong chemical bonds that hold together atoms within a molecule and result from electrons being shared among atoms. The bond that was discovered was a hybrid of a hydrogen bond and a covalent bond. This bond was named a hydrogen-mediated chemical bond. Through studies, it was shown that the hydrogen was shared equally between both fluorine atoms.

 The researchers used infrared light to set bifluoride ions vibrating and measured the hydrogen atoms’ response, revealing a series of energy levels at which the hydrogen atoms vibrated. For a typical hydrogen bond, the spacing between those energy levels would decrease as the atom climbed further up the energy ladder. But instead, the researchers found that the spacing increased. This proves that the hydrogen atom was being shared equally instead of being closely bound to one fluorine atom by a covalent bond and more loosely bound by a typical hydrogen bond to the other.

Computer calculations showed that this behavior is dependent on the distance between the two fluorine atoms. As the fluorine atoms move closer to each other, squeezing the hydrogen between them, the normal hydrogen bond becomes stronger, until all three atoms begin sharing electrons as in a covalent bond, forming a single link that the researchers call a hydrogen-mediated chemical bond. The hydrogen-mediated chemical bond can’t be described as either a pure hydrogen bond or a pure covalent bond, the researchers conclude. “It’s really some hybrid of the two,” says chemist Mischa Bonn of the Max Planck Institute for Polymer Research in Mainz, Germany.

Fluorine atoms (illustrated in green) squeeze a hydrogen atom (orange) between them when dissolved in water (red and silver). Researchers used infrared laser light (red lines) to study the chemical bond that formed (branching blue lines), which acts as a hybrid between a hydrogen bond and a covalent bond.

This discovery is something that will change the course of chemistry forever. The new observation has implications for how scientists understand the basic principles of chemistry. “It touches on our fundamental understanding of what a chemical bond is,” Bonn says. The newfound understanding of chemical bonding also raises questions about what qualifies as a molecule. Atoms connected by covalent bonds are considered part of a single molecule, while those connected by hydrogen bonds can remain separate entities. The bonds that are in limbo between the two raise questions. At what point do you go from a bond with two molecules to a bond with one molecule.

Sources:

Conover, Emily. “This Weird Chemical Bond Acts like a Mash-up of Hydrogen and Covalent Bonds.” Science News, 27 Jan. 2021, https://www.sciencenews.org/article/new-weird-hybrid-chemical-bond-hydrogen-covalent. 

Two Awarded Chemistry Nobel for Efficient Methods to Make Medicinal Molecules

 

The Swedish Nobel Committee has announced that the 2021 Nobel Prize in Chemistry will be shared by Benjamin List and David W. C. MacMillan for developing new tools to make complex molecules of interest in research and medicinal chemistry.  

The tools are particularly useful in synthesizing molecules that have structures that have what might be called "handedness."  That is like our right hand and our left hand these molecules have variations that seem similar but are actually mirror images of one another.  In chemistry this property is called "chirality" and most molecules important in biological systems have chirality.  In medicine the right handed version of a molecule may be beneficial, but the left-handed version may be harmful.  Methods to make specifically only the one or the other are therefore very valuable.

2021 Nobel Prize

Benjamin List

David W. C. MacMillan

The chiral feature is the relationship between the left hand and the right hand, which can be mirrored but not completely overlapped in space. 19 of the natural 20 amino acids have chiral characteristics. Polypeptides, proteins, and various cysts in the dynamic life process formed by using this as a basic unit have a special spatial fingerprint code, and each is distinguished from the other. Whether the transformation process is possible or not, identify the upper and lower sides of each reaction's potential. In comparison, the development of transition metal asymmetric catalysis has more context. As the first tool for humans to explore asymmetric organic synthesis, from the asymmetric cyclopropanation reported by Nozaki and Noyori to the homogeneous asymmetric catalytic hydrogenation reported by Knowles , To the asymmetric epoxidation reaction reported by Sharpless.

It was not until 2000 that this field was shaped by two important reports:

1. Reported by Professor Benjamin List, Professor Richard A. Lerner, and the late famous synthetic chemist Professor Carlos F. Barbas III, the first case of asymmetric Aldol mediated by a small organic molecule of proline via enamine intermediates The reaction, based on a similar reaction mechanism, uses small molecules to mimic the conversion process catalyzed by enzymes (Hajos-Eder-Sauer-Wiechert reaction)

2. The asymmetric Diels-Alder reaction of a chiral secondary amine via iminium, which was first reported by Professor David WC MacMillan. It is the first conceptually to clarify that "organic catalysis" can be atom-economy and environmentally friendly. A sexual approach to achieve the target reaction, and based on key intermediates, the types of reactions can be broadly expanded.

From the establishment of the concept of "organic catalysis", scientists have gradually clarified its core competitiveness: 1. Generally speaking, it is not sensitive to water and oxygen, and the technical difficulty of use, storage, and amplification is relatively low, and the reaction can be universally adapted based on the catalytic mechanism. Iterative design of types has high predictability; 2. The core framework is generally derived from naturally occurring biogenic pathways, and generally has optically pure properties, and the cost of derivative applications is low, which can facilitate the construction of catalyst libraries; 3. Small molecules generally have low toxicity, natural environment-friendly properties, separation difficulty, and low cost, especially to meet the needs of medicinal chemists. Based on the above consensus, chemists have gradually invested in the exploration of general catalytic models, which of course include the enrichment and improvement of the "enamine" and "iminium" catalytic systems based on secondary amines. With the help of enamine, the α-position of aldehydes and ketones can be achieved. A series of asymmetric functionalization and the carbonyl group of the product is used as the "reaction relay" to realize the transmission of chiral framework information, playing a key chemical synthon to participate in the construction of more complex molecules; with the help of imine ions, unsaturated aldehydes can be realized The asymmetric modification of the β-site of the compound includes the construction of heteroatom chiral center and cyclization modification. In the follow-up development, the asymmetric modification of more distant sites is gradually realized. At present, the catalysis around "amine" (enamine, iminium) is still the largest and most systematic branch in the field of asymmetric catalysis of organic small molecules, and there are still continuous outstanding achievements emerging, including being the founder and expanding The “SOMO catalysis” strategy based on single-electron transfer proposed by Professor David WC MacMillan of the author.

Among the above, proline does not only play the Lewis base catalytic function of the secondary amine, but the carboxylic acid of the side chain also plays the role of activating Brønsted acid, and this later forms another complete organic surrounding the chiral protic acid. Small molecule catalytic systems, including the Mannich-Type reaction by Takahiko Akiyama using chiral phosphoric acid in 2004, and the Aza-Friedel-Crafts alkylation of furan by Masahiro Terada. These two reports are generally considered to be the first works of chiral protic acid catalysis. Benjamin List also has an important participation in this field. In addition to further broadening the universality of classical chiral phosphoric acid, it also proposed the concept of "asymmetric counteranion-directed catalysis (ACDC)" and developed proton acidity. A stronger library of chiral organic acid molecules continues to extend the upper limit of the activation threshold under this mechanism.

From the perspective of drug creation, the core logic lies in the innovation of targets, mechanisms of action, and drug skeletons. Synthetic chemists are exploring and exploring in this range. On the one hand, they analyze the synthetic pathways and methods of active natural product molecules. Combining medicinal chemistry and biology to derive the modification, modification, assembly, and splicing of pharmacodynamic functional groups. Focusing on novel catalytic mechanisms, combined with the design and modification of catalyst frameworks, chemists explore the extension space of inherent synthesis modes, derive the construction paradigm of chiral centers (molecular fragments) containing different heteroatoms, and use this as an index and support for innovative capabilities. The theoretical support of the direction of medicinal chemistry specifically modifies the molecular skeleton of potential drugs and builds a library to link the development of the general direction of life and health. In the corner of asymmetric catalysis of organic small molecules, all members have expectations for the Nobel Prize in Chemistry. If we consider the contribution to the development of the entire field, we imagine that the two professors, Benjamin List and David WC MacMillan, deserve this prize.

Reference:

1. Benjamin List, Richard A. Lerner, Carlos F. Barbas III, J. Am. Chem. Soc. 2000, 122, 2395-2396.

2. Kateri A. Ahrendt, Christopher J. Borths, David W. C. MacMillan, J. Am. Chem. Soc. 2000, 122, 4243-4244.

3. Hye-Young Jang, Jun-Bae Hong, David W. C. MacMillan, J. Am. Chem. Soc. 2007, 129, 7004-7005.

4. Takahiko Akiyama, Junji Itoh, Koji Yokota, Kohei Fuchibe, Angew. Chem. Int. Ed. 2004, 43, 1566-1568.

5. Daisuke Uraguchi, Keiichi Sorimachi, Masahiro Terada, J. Am. Chem. Soc. 2004, 126, 11804-11805.

6. Ilija Čorić, Benjamin List, Nature 2012, 483, 315-319.

7. Sébastien Prévost, Nathalie Dupré, Markus Leutzsch, Qinggang Wang, Vijay Wakchaure, Benjamin List, Angew. Chem. Int. Ed. 2014, 53, 8770-8773.

8. Matthew S. Sigman, Eric N. Jacobsen, J. Am. Chem. Soc. 1998, 120, 4901-4902.

9. Anna G. Wenzel, Eric N. Jacobsen, J. Am. Chem. Soc. 2002, 124, 12964-12965.

10. Yong Huang, Aditya K. Unni, Avinash N. Thadani, Viresh H. Rawal, Nature 2003, 424, 146-146.

11. Sarah E. Reisman, Abigail G. Doyle, Eric N. Jacobsen, J. Am. Chem. Soc. 2008, 130, 7198-7199.

12. Ronald Breslow, J. Am. Chem. Soc. 1958, 80, 3719-3726.

The “Forever Chemicals” on Mount Everest

 Submitted by Ava Sheftick (via Great Grandpa Doug)

At an elevation of 27,600 feet researcher Mariusz Potocki was on a mission to gather snow and ice samples at the summit. His team stopped at what is known as “the balcony” where the snow was littered with feces, oxygen bottles, and other garbage. Therefore, he had to go to a lower part of the snow where he could collect bottles of cleaner snow.

However, this “cleaner” snow actually contained toxic chemicals known as PFAS, which stands for per- and polyfluorinated substances. These are a group of chemicals used to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. These include clothing, furniture, adhesives, food packaging, heat-resistant non-stick cooking surfaces, and the insulation of electrical wire. Additionally, there are several concerns associated with these chemicals. They do not break down in the environment, can move through soils to contaminate drinking water, and build up in fish and wildlife. Thus, this is why they are referred to as “forever chemicals.”

There was a similar study in 2019 by Miner called the National Geographic and Rolex Perpetual Planet Everest Expedition. It was conducted to show that our chemical fingerprints are left at even the highest elevations in the world. Their research team conducted the solid-phase extraction and liquid chromatography-tandem mass spectrometry to identify these chemicals.

14 PFAS compounds tested for, they found perfluorooctanesulfonic acid, perfluorooctanoic acid, and perfluorohexanoic acid in Mt. Everest snow and meltwater.

Figure 1. perflurooctanesulfonic acid 

Figure 2. perfluorooctanoic acid 

Figure 3. perfluorohexanoic acid 

These PFAS can lead to health effects. Such as increased cholesterol, changes in liver enzymes, and an increased risk of testicular or kidney cancer.

Cyclone Fani, was a tropical cyclone that hit India. Due to this cyclone, 10 inches of fresh snow were dropped during the expedition. Miner’s colleague Clifford took samples and they showed no PFAS. However, the findings suggest that the high levels of PFAS were not from atmospheric deposition. Instead, it appeared that they had been distributed from the gear of climbers in which they are treated to be weatherproof.

In other researchers’ samples microplastics were found. These plastics are extremely tiny (less than 5mm) and contain polyester fibers that are most likely from climbers clothing and equipment.

 Figure 4. Microplastic Display 

Overall, this article works to demonstrate how human action has an effect at even what we deem to be the top of the world. The future from this article may entail looking at ways to change climbing gear so that these chemicals are not being left at the top of the mountain and damaging the humans and the environment.

Sources:

Carpenter, Murray. “'Forever Chemicals,' Other Pollutants Found around the Summit of Everest.” The Washington Post, WP Company, 17 Apr. 2021, https://www.washingtonpost.com/science/mt-everest-pollution/2021/04/16/7b341ff0-909f- 11eb-bb49-5cb2a95f4cec_story.html.

Napper, Imogen E., et al. “Reaching New Heights in Plastic Pollution—Preliminary Findings of Microplastics on Mount Everest.” One Earth, vol. 3, no. 5, 2020, pp. 621–630., https://doi.org/10.1016/j.oneear.2020.10.020.

Resnick, Brian, and Sean Collins. “Cyclone Fani: What We Know.” Vox, Vox, 3 May 2019, https://www.vox.com/energy-and-environment/2019/5/3/18528079/cyclone-fani-what-we- know-category-4. 

 

Accidental Blue

 Posted by Bray Fedele (via Great Grandpa Doug)

Color is something we may overlook as something worth appreciation, as the discovery of colors through laboratory processes is not a common occurrence. The color blue is found in several natural settings, including animals, eyes, and bodies of water. These blues, however, are a reflection of light and theoretically are not “natively blue”. The rarity and special presence of the color blue and nature has led it to become associated with prosperity and expense.

Today, most of our blues are formed in labs by chemists, which is not an easy ordeal. Before the accidental creation of a blue pigment in 2009 (the focus of this post), the last discovery of an inorganic blue shade was created over 200 years prior in 1802 by a French chemist Louis Jacques Thenard. YInMn Blue, then, is a momentous discovery, an unexpected one at that.

Figure One: YInMn blue pigment.

This new shade of blue was discovered by Mas Subramanian, a professor at Oregon State University while working to develop an inorganic material for use with electronic devices. After removing a sample from the furnace, Subramanian was astounded at the vibrant blue pigment, and knew immediately it was something never seen before. This was entirely unexpected and even thought to be a mistake of some kind due to the use of manganese to create the pigment, which is normally seen to produce a black or brown color as opposed to blue. The blue pigment was stable, but also slightly variable, which proved to be intriguing for those in the pigment industry. 

Figure Two: The creation of YInMn blue and the different effects on pigment depending on concentration of components.

The blue pigment, YInMn, was named after the components’ symbols on the Periodic Table (Y:yttrium, In:indium, Mn:manganese). YInMn, among several other benefits, is observed to be nontoxic and even environmentally friendly, making it desirable for use in all forms. Cobalt, a similar shade of blue, is extremely toxic, making this new blue favorable. Several other blues created from plant derivatives are similarly nontoxic, but they lose their hues and durability over time, whereas YInMn blue does not. Cobalt blue and YInMn were put head to head in an experiment that analyzed their ability to keep a house cool (the roof of two houses were coated in each of these colors), and it was determined that the house with YInMn was kept 15 degrees Celsius cooler than the one with Cobalt blue. 

Figure Three: Reflection comparison of YInMn blue and similar pigments of blue containing cobalt.

This blue creation is monumental in the eyes of chemists and pigment researchers, as it is the first of its kind in centuries, and is much less harmful and more durable than its predecessors. YInMn blue is on display with several fashion, chemical, and artist collaborations. Today, about a decade after the creation of YInMN, several films have adapted this vibrant blue (Dory in Finding Dory) and other commercial businesses have employed the color as well (Crayola has a crayon with the pigment). Since its creation in 2009, YInMn blue has also been used in the creation of other colors, leading to an entire series of YInMn colors.

Sources:

1. Brown, E. N. It's not every day we get a new Blue. https://www.nytimes.com/2021/02/05/style/blue-pigment-YInMn.html (accessed Oct 4, 2021).

2. Cascone, S. How the accidental discovery of YInMn blue changed one chemist's life. https://news.artnet.com/art-world/chemist-mas-subramanian-on-the-incredible-discovery-of-yin mn-blue-973700 (accessed Oct 4, 2021).