Jelaskan Sifat kimia dari Kalomel

Calomel is a powder that is white when pure. When it is exposed to light or contains impurities it takes on a darker tint. Calomel is made up of mercury and chlorine with the chemical formula Hg2Cl2. Depending on how calomel was administered, it affected the body in different ways. Taken orally, calomel damaged mainly the lining of the gastrointestinal tract. Mercury salts (such as calomel) are insoluble in water and therefore do not absorb well through the wall of the small intestine. Some of the calomel in the digestive system will likely be oxidized into a former of mercury that can be absorbed through the intestine, but most of it will not. Oral calomel was actually the safest form of the drug to take, especially in low doses. Most of the calomel ingested will be excreted through urine and stool.

Powdered forms of calomel were much more toxic, as their vapors damaged the brain. Once inhaled, the calomel enters the bloodstream and the mercury binds with the amino acids methionine, cysteine, homocysteine and taurine. This is because of the sulfur group these amino acids contain, which mercury has a high affinity for. It is able to pass through the blood brain barrier and builds up in the brain. Mercury also has the ability to pass through the placenta, causing damage to unborn babies if a pregnant mother is taking calomel.

Kalomel difabikasi dengan dua cara - sublimasi dan presipitasi. Ketika pertama kali kalomel difabrikasi, ia dibuat melalui sublimasi. Kalomel yang dibuat melalui sublimasi cenderung berbentuk serbuk putih yang sangat halus. Terdapat beberapa kontroversi terhadap sublimasi kalomel. Banyak yang beranggapan bahwa semakin banyak kalomel disublimasi, semakin murni hasilnya. Sebaliknya, pihak-pihak yang kontra meyakini bahwa semakin sering diulang sublimasinya membuat kalomel kehilangan beberapa kemujarabannya. Pada tahun 1788, apoteker Carl Wilhelm Scheele hadir dengan mekanisme pengendapan untuk fabrikasi kalomel. Metode ini cepat populer di industri farmasi karena lebih murah dan lebih aman untuk diproduksi. Pengendapan juga cenderung membentuk garam kalomel yang sangat murni.