After the explosion of "8.12" dangerous goods warehouse in Tianjin Port, people from all walks of life talked about "cyanide discoloration". They thought cyanide was far away from us. They thought cyanide was mysterious. Is cyanide really mysterious? Next, we will know about it.

What is cyanide?

Cyanide refers to compounds with cyano group (CN), which are generally divided into inorganic cyanide and organic cyanide. Generally known cyanide is inorganic cyanide, common potassium cyanide and sodium cyanide.

How toxic is cyanide?

As a highly toxic chemical, it can be quickly absorbed by human skin, eyes or gastrointestinal tract. Sudden death can be caused by oral administration of 150-250 mg in adults, which is less than 35 mg/kg. Although cyanide is a highly toxic chemical, its unique odor prevents people from eating it by mistake and keeps their skin in contact with it for a long time. Even if the skin is directly exposed to cyanide, it can be washed out immediately with water. If the skin is mistakenly taken with sodium cyanide, it can be directly vomited for medical treatment. Therefore, hydrocyanic acid poisoning has its specific conditions and has great limitations. In addition, it is not poisonous to eat cyanide, as long as there is no problem in the content range, please see the national standards for

cyanide in food and drinking water:

Is cyanide poisoning helpful?

Cyanide toxicity is great, but poisoning can also be first aid in many ways, and there are specific drugs, so cyanide poisoning does not mean death. In addition, the human body has a strong detoxification function to CN -, and cyanide is a non accumulating poison. When a small amount of exogenous cyanide which does not produce toxic dose enters the body, it can be rapidly converted into non-toxic or low toxic substances and discharged from the body.

What is cyanide for?

Cyanide is mainly used in gold extraction, electroplating and chemical synthesis. Cyanide can synthesize common medicines and food additives such as penicillin, vitamin B6, folic acid, guanine, caffeine, and so on; common pesticides such as glyphosate, fenvalerate, paraquat, atrazine, rice blast and so on; common dyes or pigments such as indigo, kalanin, fluorescent whitening agent; common amino acids such as methionine, alanine, glycine, etc.

How did cyanide come from?

Light oil or natural gas are mostly used in industry, and by-product of acrylonitrile can also be produced, but cyanide can not be produced by industrial production, which is also widespread in nature. For example: cyanide in plants exists in seeds such as bitter almond, peach kernel, loquat kernel, linseed, baberry kernel, plum kernel, plum kernel, cherry kernel, Apple kernel and so on. Cyanide content in plants: bitter almond: 3.71g/100g, bitter almond: 3.71g/100g, plum kernel, loquat kernel, cherry kernel, chercherry, Yangmei kernel, white fruit: 2.67ugug/100g, plum kernel: 4.33ugg/100g, broad bean: 300ug/100g, Yangmei: 300g, Yangmei: 100g, Yangmei: 100g, 11.6mg/11.6mg/11mg white plum powder powder powder plum powder powder powder powder plum: 11.6mg 100g, Green plum: 10.18mg/100g, flaxseed: 38g/100g, ginkgo seed: 523 ug/100g, cassava leaf: 20.27-28.48mg/100g, cassava pieces: 4.68-9.26mg/100g, sorghum leaf and maize seedlings are 38-70mg/100g.

Cyanide is also ubiquitous in soil, and decreases with the increase of soil depth. The content of cyanide is 0.003-0.130mg/kg. Cyanide in natural soil mainly comes from soil humus. Humus is a kind of complex organic compounds, whose core is polymerized by polyphenols and contains a certain amount of nitrogen compounds. Cyanide and phenol can be produced under the action of soil microorganisms, so the background content of cyanide in soil is closely related to the content of organic matter.

Under what conditions does cyanide enter the body?

Breathing, drinking water, contacting soil or eating food containing cyanide, smoking or inhaling smoke from fires are the main ways for cyanide to enter the body. In addition, when inhaling air containing cyanide near hazardous waste disposal plants or eating food containing cyanide naturally, cyanide may also enter our body.

How does cyanide degrade?

Natural water has a strong self-purification effect on cyanide. When a small amount of cyanide enters the water, microorganisms in the water can destroy low-concentration cyanide. Cyanide can be converted into carbonate and ammonia by bio-oxidation, making it non-toxic and consuming part of dissolved oxygen in the water. Therefore, the self-purification process of cyanide in surface water is quite rapid and will not accumulate.

Because of the strong purification effect of cyanide pollution in nature, it is not easy for exogenous cyanide to accumulate in the environment and organism. Only under specific conditions (accidental discharge, high concentration of continuous pollution), cyanide pollution exceeds the environmental purification capacity, can it remain and accumulate in the environment, thus constituting a potential hazard to people and organisms. However, these cyanides are easily degraded. For example, when sodium cyanide aqueous solution is above 50 C, irreversible hydrolysis will occur to produce sodium formate and ammonia. The higher the temperature, the faster the hydrolysis rate. This property is often used in industry to treat cyanide-containing wastewater. In addition, a high concentration of cyanide can be degraded to a safe concentration within an hour with 5 times the amount of chlorine or hydrogen peroxide, so cyanide is very easy to be degraded or eliminated.

CONCLUSION: Cyanide is not mysterious. It is not only far away from us, but also near us. It has been accompanying us all the time. Only a correct understanding of cyanide will not feel so terrible, and only understanding will prevent it.