A reference substance is a substance or material that has been determined to have one or more sufficiently uniform characteristic values, and is used as a "measuring tool" in the analytical measurement industry to calibrate measuring instruments and devices, evaluate measurement analysis methods, measure the characteristic values of substances or materials, and assess the operational skills of analysts. As well as in the production process of product quality control and other fields play an indispensable role. So what are the problems to pay attention to with reference materials? The following is a small edition of Bolinda to introduce you.

(1) Type of characteristic quantity and setting method:

Some standard substances may only be applicable to a specific method or exclusive field of application, some standard substances have special values, such as the value of crystal water, should be noted in the certificate to prevent misselection and misuse;

(2) Characteristic quantity level:

The characteristic quantity level of the standard material should match the level of the daily measured sample;

(3) Acceptable level of uncertainty:

The relative uncertainty level of the characteristic quantity of the reference material should match the precision and accuracy limits in the daily measurement.

(4) Matrix and possible interference:

When the reference material is used for method validation, quality control and calibration of some measurement methods with serious matrix effects, the matrix should be as close as possible to the daily measurement sample matrix.

(5) Form:

The standard material can be prepared in different forms, such as freeze-dried and frozen samples, and the different preparation methods may lead to the same characteristics in the standard material and the real sample behavior differences, resulting in interchangeability problems, should be fully investigated before purchase;

(6) Minimum sampling amount:

As long as the minimum sampling amount is specified in the standard material certificate, the sampling amount used for measurement should not be less than the minimum sampling amount, so the purchase should consider whether the minimum sampling amount can meet the requirements of the measurement method;

(7) Dosage:

The amount of reference material purchased shall be sufficient to meet the application of the entire experimental plan, including preparation samples considered as necessary;

(8) Stability:

Before purchasing, the validity period of the purchased batch of standard substances should be confirmed to avoid expiration when using.

The above content is the introduction of these problems to be paid attention to standard substances, in addition, pay attention to the "use of standard substances" information given in the certificate of standard substances, so as not to cause the misuse of standard substances. Before using the standard material, carefully and thoroughly read the standard material certificate to ensure that the standard material can be used correctly.