Heavy metal elements (Cd), lead (Pb), arsenic (As), chromium (Cr), mercury (Hg), and beneficial elements in grains, rice, brown rice, wheat, corn, beans, and other grains and their products Rapid detection of selenium (Se); can be used in the storage, circulation, and processing of grain and oil products such as grain depots, grain inspection stations, food processing enterprises, scientific research institutes, etc. And stable.