Due to the different physical properties, chemical properties and biological characteristics of the standard material itself, coupled with the purpose, requirements and magnitude of the experiment, the standard material in the configuration process, different needs, resulting in the standard material configuration process will also have different methods, the following small series of Bolinda to introduce the different methods of the standard material configuration process.

Different methods of the standard material configuration process:

First, the general standard material is configured by direct weighing method

1. Take out the small bottle of the standard material to be allocated and place it until it returns to room temperature. Prepare the weighing tools (suitable volumetric bottle, straw or medicine spoon, paper and pen, as well as brush and toilet paper, open the balance to preheat);

2. Put a piece of white paper next to the balance, place the standard material, medicine spoon or straw, brush and other weighing tools on the white paper, wait for the 5-digit balance to stabilize (generally preheat 30min after starting), put 10ml clean volume bottle, close the glass door, and return to zero;

3. Take appropriate amount of solid standard material with a medicine spoon, absorb it with a pipette when it is liquid, carefully put it into the volumetric bottle, go deep into the bottom of the volumetric bottle as far as possible, close the glass door, and record the reading W1(the reading is close to 10mg) when the reading is stable;

4. First add about 5mL of diluent solvent, gently shake the volumetric bottle, so that the standard material is completely dissolved, use the solvent to fix the volume to the volumetric bottle scale line, plug the bottle plug, shake back and forth several times, so that it is evenly mixed;

5. Transfer the solution to a brown bottle with a solid cap, calculate the actual concentration of C1 of the standard solution, and label it;

6. The balance brush cleans the remnants inside and outside the balance, and cleans the surroundings of the balance.

Two, valuable, small amount of standard material

Tap the cap and shake the bottle so that the material gathers into the flat bottom and there is no residue on the cap

Wipe the bottle and lid, remove the label, wipe the residual adhesive with methanol if necessary, leave to dry and return to room temperature;

Weigh the whole bottle and record data W1;

Dissolve the product in the bottle with a suitable solvent (high solubility, volatile), a small amount of times, wash, transfer the solution to the volume bottle;

When washed with bottle cap;

When nitrogen is blown, there is no solvent residue in the bottle, so that the inner wall is dry, and the bottle is restored to room temperature;

Weigh the empty bottle together with the cap on the same balance and record the data W2;

The difference between the two weighing W2-W1 is the quality of the dissolved product in the volumetric bottle;

Adjust the volume of solvent to the scale line of the volume bottle, shake well, calculate the concentration of the standard liquid;

Transfer solution to solid brown bottle, label; (The label should record the name of the standard substance, the number of the standard substance, the concentration and unit of the standard substance, the configuration date, and the validity period)

3. Volatile standard substances

Easily volatile standard substances, a small amount of solvent is added in advance in the volumetric bottle, and the wall cannot be hit during the addition process, otherwise the balance reading will be unstable and easy to change;

Wait 1-2 minutes, put it into the 5-position balance, close the window, record the data W1, and return to zero;

Quickly weigh the standard material to be weighed, record the reading W2, and return to zero;

Take out the volumetric bottle and record the reading W3;

The more the difference between W1+W2 and W3 approaches zero, the more accurate the weighing process is.

The concentration of the standard liquid was calculated by setting the volume of solvent to the scale line of the volumetric bottle.

Transfer solution to solid brown bottle and label.

The above content is an introduction to the different methods of the standard material configuration process. In our daily measurement, other types of standard substances are used, which are mainly used for measurement quality control and measurement precision confirmation. Sometimes, in the absence of certified reference materials, these reference materials have to be used to carry out calibration and other activities, but it should be further assessed whether these reference materials meet the characteristics of certified reference materials, or traceability and quantitative uncertainty levels can adequately meet the traceability and accuracy requirements of measurement results.