At the beginning of the 19th century, Emperor Napoleon Bonaparte appointed chemist Jean-Antoine Chaptal as Minister of the Interior. Chaptal then commissioned fellow chemist Louis Jacques Thénard (1777-1857) to find a new blue pigment to replace the scarce and expensive lapis lazuli. To solve the problem, Thénard started with cobalt arsenate, the chemical compound used to color Sèvres porcelain blue. After numerous experiments, in 1804 he obtained an intensely blue pigment that was very stable and much cheaper than lapis lazuli. The French chemist obtained it by heating a mixture of cobalt arsenate and phosphate with alumina to a red heat. In a very short time, the new cobalt blue became a favorite with artists. It was, for example, the color used by Vincent van Gogh in 1890 in his famous composition 'Doctor Paul Gachet', which is currently in the Musée d'Orsay, in Paris. Colorless and highly unstable Barely fourteen years after its fabulous discovery - in 1818 - Thénard discovered hydrogen peroxide, also known as hydrogen peroxide, by attacking barium peroxide - a highly reactive substance - with acids. This discovery would be of enormous importance in the healthcare field for almost two centuries. Hydrogen peroxide is a colorless liquid - although in large quantities it can turn blue - and with a density greater than that of water. Each molecule is made up, as its name suggests, of two hydrogen atoms and two oxygen atoms. Hydrogen peroxide is a highly reactive compound that has been used as a disinfectant and whose concentration is expressed in volumes, which indicate the amount of oxygen released during its decomposition. Another unique feature of hydrogen peroxide is its instability, as it spontaneously decomposes into oxygen and water. This process is true, however, very slowly if not exposed to light, which explains why its containers are opaque, but in the presence of a catalyst, the process becomes very rapid. Accelerators include metals, some salts, and some enzymes, such as catalase. Toxic and inefficient: It is precisely the presence of this enzyme in animal tissues that allows hydrogen peroxide to be used as a wound disinfectant. Catalase is an enzyme belonging to the oxidoreductase group that catalyzes the decomposition of hydrogen peroxide into oxygen—responsible for the fizzing that occurs when hydrogen peroxide is applied to a wound—and water. The oxygen resulting from the decomposition creates a toxic and lethal environment for many pathogenic bacteria present on the skin, as they are anaerobic in nature. In other words, catalase allows an anaerobic environment to become aerobic. In recent decades, the use of hydrogen peroxide as a disinfectant has decreased enormously. This has been due to two reasons: on the one hand, the presence of bacterial enzymes capable of destroying it; and on the other, hydrogen peroxide is capable of damaging healthy cells in the body. MORE INFORMATION news No An ancient tomb of two brothers reveals that cranial surgeries were already being performed 3,500 years ago news Yes New secrets of Ryugu, the asteroid older than the Sun, are revealed It is precisely this harmful effect that makes it inadvisable to use hydrogen peroxide as a teeth or skin whitener, home remedies that were widely used for decades. ABOUT THE AUTHOR Pedro Gargantilla is an internal medicine physician at El Escorial Hospital (Madrid) and the author of several popular books.
