Standard solution refers to a reagent solution with an accurate known concentration, and titrators are commonly used in titration analysis. In other analytical methods, the standard solution is used to draw working curves or as a calculation standard.

When testing with a standard solution instead of a sample, the result should be consistent with the known concentration of the standard solution. If the results match, the test was performed correctly. If there is any significant deviation (greater than 10%) from the standard value, there is an error and analysis is required. The following is a small edition of Bolinda to introduce the preparation method of standard solution.

Preparation method of standard solution:

One is the direct method, that is, accurately weigh a certain amount of the reference material, dissolve it with an appropriate solvent and then set the volume into the volumetric bottle. If the reagent meets the requirements of the reference material (the composition is consistent with the chemical formula, the purity is high, and the stability is stable), the standard solution can be directly prepared, that is, the appropriate amount of the reference material can be accurately weighed, and it is prepared in a certain volume of volumetric bottles after dissolution.

The weight W of the reference material to be weighed can be calculated by the following formula: W=ΜV· molar mass of the reference material. In the formula, μm and V are the molar concentration and volume of the solution to be prepared, respectively. The concentration of standard solution can be calculated by using the above formula.

The other is the calibration method, many substances do not meet the conditions of the reference material, not suitable for directly preparing the standard solution. That is, it is first prepared to approximate the required concentration, and then the reference substance or the standard solution that has been calibrated by the reference substance is used to determine the accurate concentration.

The above content is the introduction of the preparation method of the standard solution, the standard solution is divided into imported standard solution and domestic standard solution, and the standard solution of the American Bureau of Standards (NIST) is the most authoritative abroad, and the domestic standard solution should be compared and traced before it can be used.