Definition of standard solutions and national standards

2026-03-27 10:24:45

　　Standard solution refers to a solution with a known exact concentration. It is often used as a titrant in titration analysis. In other analytical methods, standard solution is used to draw working curves or calculate standards.

　　Standard solution preparation method

　　There are two preparation methods, one is the direct method, that is, accurately weighing the reference material, bandwidth evaluation to a certain volume after dissolution; the other is the calibration method, that is, first formulated to an approximate required concentration, and then the reference material or a standard solution to calibrate.

　　A solution of known exact concentration is used as a titrant in volumetric analysis to titrate the substance under test.

　　If the reagent meets the requirements of the reference substance (composition is consistent with the chemical formula, high purity and stability), the standard solution can be directly prepared, that is, an appropriate amount of the reference substance can be accurately weighed, and it can be prepared in a volume bottle after dissolution. The weight of the reference substance to be weighed can be calculated by the following formula: W = M V · The molar mass of the reference substance. In the formula, M and V are the molar concentration and volume of the solution to be prepared, respectively. The concentration of the standard solution can be calculated by using the above formula.

　　If the reagent does not meet the requirements of the reference substance, a solution that approximates the required concentration is first prepared, and then its concentration is accurately determined with the reference substance. This process is called solution calibration.

　　Standard solution purchase channel

　　Standard solutions are divided into imported standard solutions and domestic standard solutions. Domestic standard solutions are National Reference Materials Center, National Standards Network, Environmental Protection Agency, and foreign imports include the American Bureau of Standards (NIST) and the United States Canadian Federation. Among the imported standard solutions, the standard solution of the American Bureau of Standards (NIST) has the highest authority. The domestic standard solution should be compared with it and traced to the source before it can be used. The following are some standard solutions sold by the National Standards Network for your reference. For more standard solution inquiries, please click →GNM-SCODCR-004-2013 Chemical Oxygen Demand Standard Solution 50mL/bottle, 100ml/bottle

GSB04-2837-2011 (b) Total Nitrogen Standard Solution 50mL/bottle, 100ml/bottle

GSB04-1752-2004（c） Silicate Standard Solution 50mL/bottle, 100ml/bottle

GSB04-1752-2004 (b) Silica standard solution 50mL/bottle, 100ml/bottle

GSB04-1741-2004 (b) total phosphorus standard solution 50mL/bottle, 100ml/bottle

GSB04-1723-2004 (e) Trivalent chromium standard solution 50mL/bottle, 100ml/bottle

GSB04-1723-2004(c) Total Chromium Standard Solution 50mL/bottle, 100ml/bottle

GSB04-1723-2004 (b) Hexavalent chromium standard solution 50mL/bottle, 100ml/bottle

CP-20211-5 PH standard buffer solution pH = 1.68 ± 0.0 500Ml/bottle

117300 Chloride ion (Cl-) standard solution 500 20ml

117302 Chloride ion standard solution 100μg/mL, base 20ml

GSBZ50027-94 Water quality hexavalent chromium standard sample (standard sample) 20Ml glass ampoule

GSBZ50029-94 Water quality vanadium standard sample (standard sample) 20Ml glass ampoule