There are four classes of pure water in the laboratory, namely:
1, distilled water:
The most commonly used kind of pure water in the laboratory, although the equipment is cheap, but it is extremely energy-consuming and water-consuming and slow, and the application will gradually decrease. Distilled water can remove most of the pollutants within the tap water.
2, deionized water:
Application of ion exchange resins to remove anions and cations in the water, but the water still exists in the soluble organic matter, which can contaminate the ion exchange columns and thus reduce the effectiveness of the deionized water is also easy to cause bacterial reproduction after storage.
3, reverse osmosis water:
Reverse osmosis water overcomes many of the shortcomings of distilled and deionized water, the use of reverse osmosis technology can effectively remove the dissolved salts in the water, colloid, bacteria, viruses, bacterial endotoxins and most of the organic matter and other impurities.
4, ultrapure water:
Ultra-pure water in the TOC, bacteria, endotoxin and other indicators are not the same, according to the requirements of the experiment to determine, such as cell culture on bacteria and endotoxin requirements, while HPLC requires low TOC.
Laboratory water classification and standards: national laboratory water standards (GB/T 6682) based on the purity of water (water conductivity) into 1, 2, 3 levels, 1 conductivity less than 0.1μs/cm; 2 conductivity less than 1.0μs/cm; 3 conductivity less than 5.0μs/cm;
Quanrui QTCJ series of small deionized water equipment Can meet the different needs of users, water production 10L-50L / h, water quality in full compliance with the national laboratory 1, 2, 3 standards, different levels of water production processes, production costs vary greatly, so its use is also differentiated.
Three levels of water is ** level of laboratory-grade water, recommended for glassware washing; water bath, autoclave water and ultrapure water system feed.
Second-grade water is generally used for routine laboratory applications, such as the preparation of buffers, pH solutions, and microbiological media; it is used to supply water for ultrapure water systems, clinical biochemistry analyzers, incubators, and aging machines; and it can also be used to prepare reagents for chemical analysis or synthesis.
One? Grade 1 water is often used for strict experimental applications, such as HPLC mobile phase preparation; GC blank sample preparation and sample dilution, HPLC, AA, ICP-MS and other high-precision analytical techniques; buffer, mammalian media preparation and in vitro fertilization; molecular biology reagent preparation (DNA sequencing, PCR amplification, etc.); electrophoresis and hybridization experiments, solution preparation and so on.
Often our laboratory staff uses primary standard water for secondary water in experimental applications for the sake of experimental accuracy and precision. p>
Chinese biological equipment network - laboratory pure water is divided into several grades