Nitrates - what is it? Nitrates: formula, receipt, application, action

Among the information on the problem of proper nutrition, we can distinguish a segment that reveals the influence on the human body of substances such as nitrates. Their effect on our health is ambiguous. How not to recall the famous expression of Paracelsus: "Everything is poison and everything is a medicine; One or the other does only a dose of it. " Indeed, for the correct metabolism, the presence of NO ₃ ^- NO ₄ ⁺ anions in the cytoplasm of cells is necessary. At the same time, the excess of compounds containing these ions in food is dangerous for human health. The role of nitric acid salts, their preparation, application of nitrates will be considered in this article.

The position of nitrates in the classification of inorganic substances

Many people know that nitric acid salts, which are highly soluble in water, are nitrates. What is saltpeter is not known to everyone. It turns out that earlier in the chemistry called special substances - salts of nitric acid. So far, we can hear this term applied to the chemistry of mineral fertilizers. In nitrates, nitrate ion is bound to potassium, calcium, sodium and ammonium cations. They are medium salts. It turned out that nitrates of sodium, potassium and other salts decompose on heating, the reaction products depending on which cation is a part of the molecule. Thus, nitrates, the formula of which is KaNO ₃ or NaNO ₃ , are thermally decomposed to the corresponding nitrite and free oxygen, and magnesium nitrate upon heating forms oxide, nitrogen dioxide and oxygen.

Getting nitrates

The main method is the processing of natural minerals containing nitric acid salts. Thus, Chilean nitrate, which is a mineral nitrone, is one of the main sources of their production. At the factories of the fat industry, rock containing sodium nitrate is finely ground and, in pre-packaged form, is supplied by the agricultural enterprises of the farm as a nitrogen fertilizer. Apply it primarily for the growth of the vegetative mass of vegetable, cereals and fruit and berry crops, as well as to increase their yield. In laboratory conditions, nitric acid salts are obtained by exchange reaction between alkali and nitrate acid or by the interaction of metals with concentrated HNO _3. The use of nitrogen fertilizers, such as potassium nitrate, ammonium nitrate, is a necessary condition for obtaining stable high yields of basic crops.

Agrotechnical conditions for the introduction of nitrogen fertilizers (nitrates)

They include, first of all, compliance with the norms for introducing drugs into the soil. For example, for ammonium nitrate containing up to 35% nitrogen, the allowable rate is not more than 25 g per square meter. Calcium nitrate, which contains up to 15.5% of nitrogen, is introduced at a rate of up to 50 g per 1 m. Violation of the agrotechnical norms of nitrogen fertilizing of plants leads not only to soil contamination and reduction of its reducing function, but also to the dangerous concentration of compounds such as Nitrates, in vegetables and fruits. On this issue we will dwell on.

How nitrates get into plants

Let's consider, what exactly ways nitrates enter the soil, what is pre-sowing, starting fertilizer and feeding. In agriculture, the main application of fertilizers is carried out in the spring and at the same time pay attention to the soil composition and climatic features. The goal is to ensure nitrogen nutrition during the vegetative period of the plant.

When using the starting method, saltpeter is applied directly to the rows or wells, using nitrates in minimum doses to "not burn" the fragile roots of the planted seedlings. Top dressing is performed during the most intensive absorption of nutrients by plants. It is carried out in the form of vegetative crops or as a root dressing with solutions of nitrates. In the soil substrate, ammonium ions or nitrate ions are easily absorbed by the root hairs by diffusion and then proceed to xylem. It consists of conducting elements of plants. In gymnosperms it is tracheids, and in flowering ones - vessels (trachea). The nitrogen atoms that make up the nitrates are included in the Calvin cycle, which is carried out in the dark phase by photosynthesis, and further enter into the composition of the synthesized amino acids and further into vegetable proteins.

The more dangerous is the excess content of nitrate salts

If the concentration of the above-mentioned compounds exceeds the permissible norm, it can determine a device for measuring nitrates in products. It is available on sale and is used in many families that are responsibly related to their health. Studies of medicine have proven that the excess of HNO ₃ salts in the gastrointestinal The path turns into nitrite. They cause irritation of the mucous membranes of the stomach and duodenum, symptomatic manifestations of dyspepsia and food poisoning. It was also found that excess HNO ₂ salts are poorly excreted by the kidneys, so they accumulate in the renal parenchyma. It is known that the kidneys themselves play a leading role in the metabolism and excretion of harmful metabolic products. Reduction of the filtration function of the kidneys is a very dangerous complication resulting from poisoning with salts of nitrogen and nitrous acids. As a result of eating foods with a high content of nitrates, the liver, which is another detoxifying organ, also suffers. Its damage with nitrates is fraught with severe damage until the degeneration of hepatocytes into adipose tissue.

Oxygen starvation of tissues as a consequence of their poisoning with nitrates

Nutrients (fats, carbohydrates) can be stored as a spare energy source and consumed by the body gradually. That's why a person is able to do without food for 5-7 days. But oxygen, unlike carbohydrates and fats, can not persist in cells or tissues for a long time, therefore, hypoxia for 5-15 minutes leads to the death first of the brain cells, and then of the entire human body as a whole. Seemingly innocuous, nitrates in fruits, vegetables, and infant formula can cause the destruction of the respiratory chains in the mitochondria, disrupt the formation of the erythrocyte-hemoglobin-pigment bond with the oxygen molecules.

And to prevent its transfer to organs and tissues. Therefore, excessive concentration in the cytosol of cells of compounds such as nitrates (formula - Me (NO ₃ ) N ₁₎ can lead to serious impairment of functions on the part of such physiological systems as digestive, excretory, and also nervous.

What foods can be contaminated with nitrate salts

In most people, the excess content of these substances is associated with vegetables or fruits, such as watermelon, potatoes, radish or strawberries. But it turns out that the pollution of the soil and especially water with nitrogen fertilizers that got there due to violation of the norms of their application directly leads to the "subsidence of nitrates" in the organisms of domestic animals. Therefore, uncontrolled and irrational use of nitrates entails their high content in livestock products: meat, milk and even honey. Spraying of plants-honey plants (buckwheat, rape) with solutions of nitric acid salts as a liquid fertilizer leads to the appearance of toxins in bee products.

How to determine the content of nitric acid salts in products

Let's clarify how it is practically possible to learn about the concentration in nutritional substances of compounds such as nitrates. What is a nitrate tester, consider in more detail. In order to detect the presence of nitric acid salts, it is necessary to dip the instrument probe into the pulp of a watermelon or other product. The device has two parts: positive and negatively charged. And the nitrate meter itself determines the electrical conductivity of the cell-juice solution. The results obtained are compared with the MPC of the test product, and a device for measuring nitrates in products displays a result with the content of salts in mg / kg. Especially desirable is testing of food products used in the nutrition of young children, pregnant and lactating women, as well as people suffering from chronic gastrointestinal and kidney diseases.

Nitric acid salt poisoning and its prevention

The peak of recorded cases of intoxications associated with poisoning with salts of nitric acid is passed at the end of winter - the beginning of spring. Due to the lack of sunlight and energy, the human body during this period is in dire need of vitamins contained in fresh vegetables and fruits. Therefore, supermarkets do not contain greenhouse cucumbers, tomatoes, spicy flavors (celery, parsley, dill), as well as strawberries. Agrotechnologies for their cultivation require the mandatory use of substances such as nitrates. What is mineral fertilizers and how their excess affects the human body, has already been considered by us earlier. Now we will focus on first aid measures that can alleviate the condition of a patient with symptoms of nitrate poisoning. First of all, you need to induce vomiting to remove from the stomach a toxic product. To do this, use a generous drink. Then take drugs-enterosorbents and continue to observe the water-salt regime. With complex symptoms such as a drop in blood pressure, loss of consciousness, seizures caused by central nervous system damage and kidneys, an "ambulance" should be urgently called.