As a benchmark substance for analysis and testing, the preservation quality of standard samples directly affects the reliability and comparability of experimental data. Scientific storage management requires the construction of a multidimensional protection system, forming a complete closed loop from environmental control to operational norms. The standardized storage plan is described in detail below from six core elements.
1、 Accurate control of environmental parameters
The constant temperature system is the primary guarantee, and most standard products need to be stored in a refrigerated environment at 2-8 ℃, with temperature fluctuations controlled within ± 2 ℃. Special categories such as volatile organic compounds require low-temperature zoning (-20 ℃), while metal element standard solutions can be stored in a cool and shady place. Humidity control is equally crucial, and the constant humidity chamber should maintain a relative humidity of 40% -60% to prevent microbial growth and container corrosion. Dark storage uses brown glass bottles or aluminum foil wrapping, with a UV shielding rate of over 99%, especially suitable for photosensitive compounds.
2、 Container selection and sealing technology
High borosilicate glass ampoules have chemical inertness that can resist acid and alkali corrosion. The second choice of PTFE lined spiral mouth reagent bottle requires matching PTFE sealing gasket. Organic solvent standards must use pressure tanks with pressure relief valves to prevent concentration deviations caused by volatilization. All containers must be clearly labeled with an expiration date, and after opening, an opening date label should be affixed to the bottle body, strictly following the "first in, first out" principle.
3、 Partition classification and three-dimensional management
Establish a three-level zoning system: ordinary chemical area, high-risk reagent area (highly toxic/explosive), and biological product area. Each type is equipped with an independent ventilation system, emergency eye wash stations, and shower devices. The shelves are made of corrosion-resistant stainless steel material, with a layer spacing of not less than 30cm for easy air circulation. Dangerous goods are subject to dual person and dual lock management, with electronic ledgers recording access information in real-time. Place standard samples with similar concentration gradients adjacent to each other to reduce the risk of accidental retrieval.
4、 Standardized access process
Implement the "three checks and six pairs" system: verify the name, concentration, and batch number before sampling; Check the integrity of the seal when opening the bottle; Refer to the certificate number when using. The pipetting operation must be carried out in a biosafety cabinet, equipped with a metrologically certified micropipette. Cover the used container immediately and return it to its original position. Do not leave it open for a long time. Volatile standard products are prepared and used immediately, and the remaining mother liquor needs to be sealed with nitrogen gas for storage.
5、 Dynamic monitoring and early warning mechanism
Install an automatic temperature and humidity recorder, and upload the data synchronously to the LIMS system. Conduct a monthly visual inspection to observe changes in solution color and precipitation formation. Standard products with near expiry date will be transferred to the inspection area three months in advance, and the feasibility of renewal will be evaluated by the quality manager. Expired standard products shall be recycled according to the hazardous waste disposal process, and unauthorized dumping is strictly prohibited.
6、 Special category specialized management
Isotope markers need to be equipped with lead plate shielding covers, and radioactive standard sources should be stored in dedicated safes. Protein standards should be treated with sodium azide for preservation, and freeze-dried powder forms should be divided into single doses to avoid repeated freezing and thawing. Gas cylinders are fixed inside explosion-proof walls and equipped with two-stage pressure reducing valves and leak alarm devices.
By constructing a three-dimensional preservation network that covers environmental control, container management, operational standards, and monitoring systems, the degradation rate of standard products can be controlled within 0.5% per year, ensuring the accuracy of value transmission. It is recommended to entrust CNAS certification agencies to conduct periodic inspections of standard products every year, establish a complete traceability chain, and lay a solid foundation for laboratory quality control.