[miniaturization common sense] approach phenolphthalein
In junior high chemistry you learned about acid-base neutralization reactions, and we used phenolphthalein as a reagent. Is your impression of phenolphthalein still that it’s just an indicator? Let’s take a look at phenolphthalein today.
Phenolphthalein, also known as fenofurtaline, is a chemical product in the form of crystalline powder that is almost insoluble in water. It is colorless in acidic and neutral solutions and purplish red in alkaline solutions. It is often used to detect acid and base.
Phenolphthalein is a stimulant laxative, mainly acting on the large intestine. After oral administration, soluble sodium salt is formed in the alkaline environment of the intestine, which stimulates the nerve plexus in the intestinal wall, directly acts on the smooth muscle of the intestine and increases intestinal peristalsis. At the same time phenolphthalein also inhibits the absorption of water in the intestinal tract, so that water and electrolytes accumulate in the colon, resulting in laxative effect. Its action intensity is related to the size of intestinal alkalinity, and its action is mild, rarely cause intestinal spasm.
Phenolphthalein took effect 6 ~ 8h after oral administration. About 15% of the absorbed drugs are absorbed after oral administration. The absorbed drugs are mainly excreted in the form of glucuronides through the kidneys or feces, and some of them can also be excreted through bile to the intestine, where they can be reabsorbed to form enterohepatic circulation, thus prolonging the action time. Therefore, the action can last for 3 to 4 days after a single administration. The unabsorbed part is excreted in the feces. Phenolphthalein can also be secreted by milk.
Phenolphthalein has other uses besides being a drug
it can be used in organic synthesis is mainly used in synthetic plastics, especially the synthesis of dinitrogen miscellaneous naphthalene poly (aryl ether ketone ketone polymer poly (aryl ether ketone, this kind of polymer because it has excellent heat resistance, water resistance, chemical corrosion resistance, heat aging resistance and good processing formability, fiber, coating and made of the composite materials is widely applied in many areas, such as electronic appliances, mechanical equipment, transportation, aerospace, nuclear engineering and military and other fields.