Storage Requirements for Laboratory Pure Water and Ultrapure Water

In various laboratory experiments, pure water and ultrapure water are frequently used. Their purity directly affects the accuracy and reliability of experimental results. However, many people may overlook the fact that even high-quality pure and ultrapure water prepared using advanced equipment can quickly become contaminated if improperly stored, leading to a decline in water quality and consequently affecting experimental results. Therefore, proper storage requirements are crucial.

Ultrapure water should be used immediately to minimize contact contamination.

Ultrapure water is easily contaminated by the environment after collection, so immediate collection (use immediately after collection) is the best approach. Only by minimizing the contact time between ultrapure water and the environment can the high purity of the obtained ultrapure water be maintained. For example, in trace analysis experiments with extremely high water quality requirements, if ultrapure water is taken out in advance and left for a period of time, it is highly likely that impurities such as dust and microorganisms from the environment will mix in, introducing interfering substances that were not originally present in the water, leading to deviations in experimental data.

Control storage time and clean water tanks regularly.

Pure water stored in storage tanks for extended periods will gradually accumulate impurities, and microorganisms will also proliferate, causing water quality deterioration. Therefore, it is not advisable to store pure water in the water tank unused for extended periods. If not in use, the water should be emptied and the tank cleaned regularly.

Install an air filter to isolate environmental impurities.

An air filter is installed in the water tank to prevent contamination from environmental factors. When water is used, outside air can enter the tank and cause contamination. UPU's patented double-layer PE sterile water tank (ZL201610787560.5) is equipped with a breather, effectively isolating air and further ensuring water safety.

Store away from light to inhibit microbial growth.

Do not place the water tank in direct sunlight. Sunlight raises the water temperature, creating favorable conditions for microbial growth. Especially for semi-transparent water tanks, sunlight can penetrate the walls, potentially leading to algae growth. Once algae grow in the water, they not only consume dissolved oxygen but also release organic matter, further polluting the water.

Discard the initial outflow to ensure stable water quality

When drawing ultrapure water, discard the initial outflow to obtain stable water quality. Impurities may adhere to the pipes and water inlet; the initial outflow will carry these impurities, affecting the quality of subsequent use.

Avoid connecting hoses after terminal filters to ensure water purity

Avoid connecting hoses after terminal filters whenever possible. Direct water intake is recommended to obtain high-purity ultrapure water. Connecting hoses may cause secondary contamination of the ultrapure water due to leaching from the hose material or microorganisms adsorbed and growing on the inner wall of the hose during use.

The storage of laboratory pure water and ultrapure water requires strict control from multiple aspects. Correct storage and water intake are essential to ensure high-quality experimental water, providing a solid guarantee for the smooth conduct of experiments and the acquisition of accurate results.