COD Calibration Standard (C09-0796-905)

product descriptionThe standard material of this solution is mainly used in the measurement of chemical oxygen demand (Mn method), to calibrate the instrument or to perform the quality control and method evaluation of the analytical process.1. Sample preparationThe standard substance of this solution uses pure glucose as the raw material, and uses three-time purified water (electro-osmosis, ion exchange, and quartz distillation) without organic substances as the solvent, and is prepared by gravimetric method in a clean room with a room temperature of 20℃±2℃ . After batch preparation, it is divided into 20ml ampoules and subjected to high temperature and high pressure sterilization.2. Traceability and valuation methodThis standard substance uses the potassium permanganate volumetric method to determine its value. The quantity value of this standard substance can be traced to the national standard of purity of standard reagents stored in the Chinese Academy of Metrology through the selected potassium permanganate solution standard substance and S117539 sodium oxalate purity standard substance. Through the use of measuring methods and measuring instruments that meet the requirements of metrological characteristics, the traceability of the quality value of the standard material is guaranteed.3. Characteristic value and uncertaintySKUnameConcentration standard value (mg/L)Relative expanded uncertainty (%, k=2)C117604COD Calibration Standard2373In the uncertainty evaluation, the uncertainty components introduced by measurement repeatability, weighing, endpoint judgment, potassium permanganate solution standard material, sodium oxalate solution standard material, uniformity and stability are considered.4. Uniformity inspection and stability inspectionIn accordance with the requirements of JJF1343-2012 "General Principles and Statistical Principles for the Valuation of Reference Materials", the potassium permanganate volumetric method is used, and samples are selected for uniformity inspection according to random sampling rules, and the F test method is used to determine that the samples are uniform. Using the same measurement method, in line with the principle of dense first and sparse later, samples are randomly sampled regularly for stability inspections to prove that the samples are stable. This standard substance has a validity period of 1 year from the date of value determination. The development unit will continue to track and monitor the stability of the reference material, and if any changes in the value are found within the validity period, the user will be notified in time.5. packaging, storage and useThe standard substance is packaged in glass ampoules, each 20mL, and should be stored in a dark, cool and dry place. Before use, equilibrate at room temperature (20±5°C) and shake it evenly. Use a clean pipette to accurately pipette 10mL from the ampoule and place it in a 1L volumetric flask (diluted to 1/100 for use) with pure water. This standard substance Provide the concentration standard value before dilution. The temperature of the water bath should be kept at a boiling state of 100°C. When the sample is heated in a boiling water bath, cover with a watch glass. When titrating under acidic conditions, the reaction temperature of sodium oxalate and potassium permanganate should be maintained at (60~80)℃. A blank experiment should be done at the same time. Specification: 237mg/L in water Related Documents: https://ald-pub-files.oss-cn-shanghai.aliyuncs.com/aladdinsci/pdp/sds/1/C117604-SCI_36e8c11ff80fc62e293605bf7ae1e16d.pdf