The nine boundary indicators specified in the national standard include lithium, strontium, zinc, selenium, bromide, iodide, metasilicic acid, free carbon dioxide and total dissolved solids. One or more of them must meet the requirements of the boundary index of mineral water, and the required content is (unit: mg/L): lithium, zinc and iodide are all ≥0.2, and selenium is ≥0.0 1.
Choose mineral water, don't choose products whose quota index exceeds the national standard. Pay attention to whether the bottle cap is loose, whether the bottle body is bright and whether there are foreign objects floating. In addition, the surface tension of mineral water is large, so a coin can float on mineral water, but not on ordinary drinking water.
China's national standard for drinking natural mineral water stipulates that drinking natural mineral water is unpolluted underground mineral water that naturally gushes out from the depths of the ground or is artificially exposed; Contains a certain amount of mineral salts, trace elements and carbon dioxide gas; In general, its chemical composition, flow rate, water temperature and other dynamics are relatively stable within the natural fluctuation range. The "National Standard" also determines the limit indicators that meet the standards of mineral water, such as lithium, strontium, zinc, bromide, iodide, metasilicic acid, selenium, free carbon dioxide, dissolved total solids and so on. One (or more) indicators must meet the above components before it can be called natural mineral water. The "national standard" also stipulates that the limit index and hygiene index of radioactive substances are to ensure the safety of drinkers. Generally speaking, according to the water quality composition of mineral water, beneficial elements contained in mineral water has no substantial physiological or pharmacological effects on occasional drinkers. However, if mineral water is drunk for a long time, it does have obvious nutritional and health care effects on the human body. Taking metasilicic acid, lithium and strontium in natural mineral water in China as an example, these elements have similar biological effects to calcium and magnesium, and can also prevent hypertension, protect the heart and reduce the incidence and mortality of cardiovascular and cerebrovascular diseases. Therefore, the content of metasilicic acid is one of the most commonly used and important boundary indicators for evaluating the quality of mineral water in the world. Lithium and bromine in mineral water can regulate the activity of the central nervous system and have the effect of calming the nerves. Drinking mineral water for a long time can also supplement the deficiency of nutrients such as calcium, magnesium, zinc, selenium and iodine in the diet, enhance the immune function of the body and delay aging. It also has a good effect on preventing tumors, hypertension, gout and rheumatic diseases. In addition, most mineral water is slightly alkaline, which is suitable for the physiological characteristics of human environment, is conducive to maintaining normal osmotic pressure and acid-base balance, promoting metabolism and accelerating fatigue recovery.