The blood volume detected by pricking fingers is mainly routine blood examination, and the blood volume of pricking fingers is too small to ensure the need of detecting trace elements, so blood should be drawn from the arm to detect trace elements.
Extended data:
The difference between inspection and inspection is that:
① There are more kinds of trace elements in hair than in blood, and the content (except a few) is higher than in blood, so the determination of trace elements in hair is more accurate than that in blood.
② Blood only reflects the human trace element level of 1 for a moment or two days, while hair reflects the human trace element level of 1 for a period of time or two months, so hair measurement is more accurate than blood test (hair is the final product of human nutrition absorption and metabolism).
3. Hair has the function of "recording silk" on the exposure of trace elements in human body, which is a reflection of the health status of human body after metabolism. Measuring the content of trace elements in 2 ~ 3 cm hair slices can trace back the trace elements of the person and expose his history, but blood test can't.
④ The Ministry of Education approved "Scientific Evaluation of Trace Elements Detection in Hair" as 2 1 textbook of Century Medical University: "Hair is the most ideal living material for human diagnosis, and the content of trace elements in it can reflect the nutritional metabolism of trace elements in the body, which is related to the occurrence of many diseases".
It is generally believed that the content of trace elements in hair is more stable than that in serum, and hair has the advantages of convenient sampling, easy storage and transportation. As an ideal biopsy material and environmental biological indicator sample, it has been widely used in medicine, nutrition and environmental science. "
References:
Baidu encyclopedia-trace element detection