Let’s all talk about the toxicity of silver nitrate and mercury nitrate
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After working in the plant for ten years, I’ve noticed that mercury nitrate has always been used for analyzing chloride ions in brine. Apparently, silver nitrate was used a long time ago; however, after someone made a reasonable suggestion—that mercury is cheaper than silver and thus helps reduce costs—mercury nitrate became the preferred reagent. Here’s the problem: those colleagues who used the mercuric nitrate standard solution experienced allergic (toxic) symptoms to varying degrees. Small blisters appeared in the spaces between their fingers on the left hand – the hand used to turn the stopper of the burette – and it was extremely itchy. Those who used silver nitrate did not experience similar symptoms. Which is more toxic, mercuric nitrate or silver nitrate?
Silver nitrate is used; mercury is too toxic. University laboratories use silver nitrate, but I’ve never seen anyone use mercuric nitrate.
This is also a reasonable suggestion: lol. More than twenty years ago, it was suggested to reduce the use of mercury nitrate. Typically, only economic benefits are considered, without assessing safety (occupational health).
Mercuric nitrate is highly toxic; mercury ions can inactivate enzymes containing thiol groups, rendering them dysfunctional； It can also bind to amino groups, dithiol groups, carboxyl groups, hydroxyl groups in enzymes, as well as phosphoryl groups in cell membranes, causing corresponding damage. Mercury poisoning causes systemic symptoms such as headache, dizziness, fatigue, insomnia, vivid dreams, stomatitis, and fever. There may be loss of appetite, nausea, abdominal pain, diarrhea, etc. Some patients develop red maculopapules on their skin. In severe cases, interstitial pneumonia and kidney damage can occur. Oral ingestion can cause acute corrosive gastroenteritis; in severe cases, it may lead to coma, shock, and even necrotizing nephropathy resulting in acute renal failure. Irritating to the eyes ； It can cause dermatitis. Chronic poisoning is associated with a neurasthenia syndrome ； Excitability, psychiatric and emotional disorders such as timidity, shyness, irritability, and crying easily ； Mercury toxicity tremor ； Stomatitis. In a few cases, there is liver and kidney damage. Silver nitrate is a strong oxidizing agent, a corrosive substance, and an environmental pollutant. When ground or impacted together with certain organic substances or sulfur and phosphorus, it can burn or explode ； Silver nitrate is corrosive. Once the skin comes into contact with silver nitrate solution, black spots appear, due to the formation of black protein silver. Silver nitrate is toxic, with an LD50 of around 50 mg/kg and a lethal dose of approximately 10 grams. Silver nitrate is somewhat toxic; when it enters the body, it causes severe irritation to the gastrointestinal tract. The lethal dose for adults is approximately 10 grams. Lethal dose for 50% of the population (mice, oral) is 50 mg/kg. Accidental ingestion of silver nitrate can cause severe abdominal pain, vomiting, bloody stools, and even gastrointestinal perforation. It can cause burns to the skin and eyes. Workers with long-term exposure to this substance may develop systemic argyria. The manifestations include extensive pigmentation of the entire skin, appearing gray-blue-black or light slate-colored ； Silver deposition in the eyes causes eye damage ； Silver deposition in the respiratory tract causes chronic bronchitis and other conditions. The above is quoted from Du Niang.
They are all toxic; relatively speaking, silver nitrate is less toxic than mercury. Wear disposable latex gloves when performing titrations
In work, try to use environmentally friendly chemicals and reduce the use of substances that cause significant harm to the environment.
Mercuric nitrate is more toxic, but its effect on the skin is minimal; mercury salts were once used in some cosmetics and skincare products. However, silver nitrate is highly corrosive to the skin and acts very quickly; if you apply a little silver nitrate solution to your hand, brown stains will appear after about half an hour. But silver nitrate is not highly toxic.