More and more trace analysis experiments require the determination of ultra-low concentrations in the ppb and ppt levels. The general materials currently used will inevitably react with the stored samples, reagents or standard solutions without special treatment, resulting in incorrect results in trace analysis experiments. Our PFA volumetric flask can just make up for its shortcomings. It has a low blank value of metal elements, the content of lead and uranium is less than 0.17ppb, no dissolution and precipitation, and a very low background. It not only has good resistance to temperature and various chemical agents, but also has the advantages of convenient cleaning. This product is mainly used for trace analysis, isotope analysis and other experiments.