There are two methods for the extraction of the standard solution, mainly the direct preparation of the reference substance and the calibration of the standard solution with known accurate concentration for extraction. The accuracy of the concentration of the standard solution is directly related to the precision and accuracy of the detection results, and the preparation conditions have very strict requirements. Below, Bolinda Xiaobian to share with you the following self-prepared standard solution must have 8 basic requirements.

A self-prepared standard solution must meet 8 basic requirements:

(1) Solutes or reference substances with high purity (such as metals, metal oxides or metal compounds) should be used; Acids, bases, metal-organic compounds, suitable salts, organic solvents, etc.)

2, in order to ensure the reliability and accuracy of the preparation of standard solutions, laboratory equipment and environmental facilities should meet its requirements,(should monitor, control and record environmental conditions. Especially for dust, electromagnetic interference, radiation, temperature, humidity, power supply, etc.).

3, with the weighing requirements of the equipment, should have the correct weighing of the electronic analytical balance, and through periodic verification, there is a certificate of quality inspection department verification.

4, there must be a high purity solvent for the preparation of standard solution (double distillation of deionized water, high purity concentration of acid, alkali or organic solution).

5, the utensils used in the preparation must be cleaned according to the requirements of the measured project, and meet the specific cleaning requirements, to ensure that the standard solution is pollution-free and does not have adverse effects on the detection.

6, clean high-quality hard glass volumetric bottles should be used as the final volume container.

7, according to the requirements of the standard solution on the container, the standard solution must be stored in a clean vessel with appropriate materials, and the prepared standard solution must be placed according to the specified requirements (such as avoiding light, ventilation, cool, refrigerated, etc.).

8, the original records of the preparation of the standard solution must be registered, the label of the standard solution must be filled in completely (such as the name of the standard solution, the concentration of mg/ml or mol/ml, the preparation person, the preparation date, the expiration date, etc.), and the label must be affixed to the reagent bottle.

The above content is the introduction of the 8 basic requirements that the self-prepared standard solution must have. The self-prepared standard solution as the working standard solution is generally used for daily inspection and analysis, and is not used for other test results with legal effects. Unless it can be shown that its properties as a reference standard for measurement do not fail. In the storage process, the standard solution should avoid direct contact with the plastic bakelite bottle cap.