A.C.S., ASTM D-1193-99 Type III, NSN: 6810-00-356-4936
While distilled water and deionized water
are fairly common, reagent water is a different kettle of fish. Those types of water may be considered “pure,” but pure is not good enough for reagent water—reagent water must be ultrapure. (Scroll down to learn more about reagent water requirements.)
In most clinical laboratories, reagent water is one the most widely used solvents, if not the
most widely used. But what are the scientific requirements of “reagent water”? And how does reagent water react with other chemicals and compounds found in research and laboratory settings?
NuGenTec offers SDS (safety data sheet) and MSDS (material safety data sheet) downloads to help you keep track of the applicable chemical, reactivity, and safety standards for reagent water. Follow the links above
to find the document(s) you need, or contact us
for more information.
What is Reagent Water?
A “reagent” is any substance or compound that is added to a system to generate a chemical reaction; reagents can also be used to test whether any reaction will occur at all.
For commercial and laboratory purposes, the term “reagent-grade” is used to designate chemical substances that meet the purity standards required to ensure the precision and reliability of chemical reactions, chemical analysis, and/or physical testing. Purity standards are specified by the American Chemical Society, ASTM International, and other similar organizations.
Reagent-grade water may contain only very low levels of sodium, chloride, silica, bacteria, and other impurities, and must provide very high electrical resistivity. Even a tiny amount of impurities can cause a sample of water’s electrical resistivity to decrease significantly. For example, just 25 ppb (parts per billion) of salt dissolved in otherwise-purified water will raise its electrical conductivity (the opposite of resistivity) to the maximum level allowed by ASTM Type I reagent water standards.
Basic Requirements for Reagent Water
In simpler terms, reagent water is more than just pure—distilled or deionized water can be said to be “pure water.” Instead, reagent water must be ultrapure. The most basic specifications for reagent water include:
- Bacterial contamination: ≤10 cfu/ml
- Electrical resistivity: ≤10 megaohm at 25°C
- Final filtration: minimum 0.22 microns
- Organic impurities: ≤500 ppb