Method For Preparing Sodium Nitrite And Preservation Method

Inspection of sodium nitrite:
Identification with salt: Differentiating sodium nitrite and salt, the sample can be placed in a solution of potassium iodide in sulfuric acid, followed by starch. If it is blue, the sample is confirmed to be sodium nitrite.

Method for preparing sodium nitrite:

Sodium nitrite has high thermal stability and can be prepared by high temperature thermal reduction method: Pb (powder) + NaNO3 = PbO + NaNO2, product PbO is insoluble in water, the reaction mixture is dissolved in hot water, filtered and recrystallized to obtain white crystalline form. Sodium nitrite.

Preservation of sodium nitrite: Sodium nitrite releases oxygen when it is heated, and it decomposes in the presence of acid and loses its effectiveness. Therefore, the container should be closed when stored.

The cause of poisoning by ingestion of sodium nitrite is that the iron contained in hemoglobin in the human body is ferrous iron, which can combine with oxygen to transport oxygen to various parts of the body. When sodium nitrite is ingested, a chemical reaction occurs in the blood to convert hemoglobin into hemoglobin of ferric iron. The hemoglobin of ferric iron cannot carry oxygen, thus causing hypoxia poisoning in humans.