How to detect heavy metals

Heavy metals are widely present in nature, including soil, air, and even water, which contain different types of heavy metals. For example, particles that harm the skin, free radicals that cause aging, car exhaust, particulate matter in the air, and even tap water all contain heavy metals. The accumulation of heavy metals in the human body poses a significant threat to health.

Generally, metals with a relative density above 4.5g/cm3 are called heavy metals. There are 60 natural metal elements with atomic numbers ranging from 23 (V) to 92 (U). Except for 6 of them, the relative density of the remaining 54 metals is greater than 4.5g/cm3. Therefore, in terms of relative density, these 54 metals are all heavy metals. However, when classifying elements, some belong to rare earth metals, while others are classified as refractory metals. Ultimately, the 10 metal elements that are truly classified as heavy metals in industry are copper, lead, zinc, tin, nickel, cobalt, antimony, mercury, cadmium, and bismuth. These 10 heavy metals have no special commonalities except for their metal commonality and density greater than 4.5g/cm3.

The commonly recognized methods for heavy metal analysis include ultraviolet spectrophotometry (UV), atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), inductively coupled plasma (ICP), X-ray fluorescence spectroscopy (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). In addition to the above methods, microspectral technology also introduces spectroscopic methods for detection, which has higher precision and accuracy.

Heavy metals refer to metals or similar metals such as lead, arsenic, cadmium, mercury, hexavalent chromium, zinc, etc.

Due to the further development of industrial activities, heavy metals such as lead, cadmium, mercury, and arsenic gradually accumulate in the human living environment. After entering the human body through air, food, water, etc., they will gradually accumulate and cause chronic poisoning, greatly endangering human health. The toxicity range of heavy metals in natural water bodies is generally between 1-10mg/L, while the toxicity range of heavy metals such as mercury and cadmium is between 0.01-0.001mg/L.