The stability of COD pre made reagents widely used in water quality monitoring directly affects the accuracy and reliability of detection results. Scientific storage management not only extends the validity period of reagents, but also ensures the comparability of experimental data. The following analyzes the key points of professional storage from three dimensions: environmental control, container management, and operational standards.
1、 Accurate control of environmental factors
Constant temperature storage is the primary principle. Most pre made reagents require refrigeration storage at 2-8 ℃, which can inhibit microbial growth and chemical reaction rates. Specialized medical refrigerators are superior to household refrigerators due to their higher temperature control accuracy and smaller fluctuations. It should be noted that refrigeration equipment should not be powered off at will, as frequent temperature fluctuations can accelerate the degradation of reagents. Protecting from light is equally crucial, as UV and visible light may trigger photosensitive reactions. Using original brown opaque bottles or secondary packaging wrapped in aluminum foil can effectively block light. Humidity control is often overlooked, as humid environments can cause reagents to absorb moisture and clump. It is recommended to store them in a dryer or a sealed container with silica gel desiccant.
2、 Container and Packaging Management Standards
Maintaining the integrity of the original packaging is crucial. Most commercially available reagents use nitrogen filled packaging, and damaging the airtight environment can lead to intensified oxidation reactions. Opened reagents should be transferred to brown volumetric flasks with ground glass stoppers, and the use of metal cap containers is strictly prohibited to prevent corrosion. Special attention should be paid to the phenomenon of stratification. Reagents containing suspended solids should be shaken thoroughly before use, while precipitation type reagents should be carefully aspirated for the supernatant. Independently packaged small ampoules have obvious advantages, as they can accurately control the single dose and avoid cross contamination caused by repeated bottle opening.
3、 Refined operation management system
Establish a strict registration system for requisition, follow the principle of "first in, first out", and ensure that reagents stored first are used first. Tighten the bottle cap immediately after each use to reduce air contact time. The pipetting operation should be carried out in a fume hood, and nitrile gloves should be worn to prevent skin oil contamination of the reagent. Special attention should be paid to special labeled reagents, such as "highly toxic" and "corrosive", which need to be stored separately in explosion-proof cabinets and managed by two people and two locks. Regularly clean expired reagents, and set warning signs for products approaching their expiration date of three months. If necessary, conduct performance verification experiments.
4、 Emergency Response Plan for Abnormal Situations
When abnormal color or turbidity is detected in the reagent, it should be immediately stopped and the cause traced. Mild precipitation can be dissolved by heating in a water bath (not exceeding 40 ℃), while severe deterioration requires disposal according to hazardous waste procedures. During transportation, severe vibrations should be avoided, and after long-distance transportation, it should be left to stand for 24 hours before use. The laboratory should be equipped with an emergency flushing device. In case of accidental contact with reagents, rinse immediately with plenty of water and take corresponding first aid measures according to the MSDS.