First-order ultrapure water is wate

First-order ultrapure water is water with physical purity greater than 18M-cm, and the previously mentioned 18.2 m-cm habit is called the conductivity index of first-order ultrapure water. Grade I pure water can be formulated as a solution for trace metal analysis. It can be used in life science experiments that require high water purity and in high precision analytical experiments that have strict requirements, including experiments that require particles, such as High-performance liquid chromatography water. First Grade ultrapure water must be purified from second or second grade water by nuclear grade Ion-exchange Resin, which means that the second grade water is treated with either quartz equipment distilled water or an ion exchange mixing window, then 0.2 nanometer microporous membrane filtration is used to prepare the first grade ultrapure water.