Sample pretreatment experiments suitable for analyzing dozens of elements in geological and mineral samples, such as Mo, Ba, V, Si, Se, Li, Ga, Fe, Mg, Zn, Hg, K, etc. Strong corrosion resistance and high temperature resistance; Covers and bodies can be digitally numbered without confusion; The design of a V-shaped bottom makes it more convenient to collect a small amount of samples; The U-shaped bottom design is suitable for the detection of physical and chemical exploration samples. Application: Sample analysis and digestion experiments in geology, geology, geochemistry, soil microorganisms, etc