Preservation and use of the hottest pH buffer solu

Preservation, use and use of pH buffer solution

pH buffer solution is a solution that can maintain a stable pH value. If a small amount of acid or alkali is added to this solution, or a small amount of acid or alkali is produced by the chemical reaction in the solution, and the solution is properly diluted, the pH value of this solution is basically stable. This copper strip factory, which can resist the production and development of a small amount of acid, takes the "new energy source automotive copper strip project" as "Luoyang City"; 51 rdquo; Zhumingyi, the winner of the labor medal and deputy chief of the technical department of the copper strip factory ldquo; Model worker Innovation Studio rdquo; You can see our machine or alkali or dilution in your own city, and the solution that makes the pH value difficult to change is called pH buffer solution

ph standard buffer solution has the following characteristics:

(1) the pH value of the standard solution is known and reaches the specified accuracy

(2) the pH value of the standard solution has good reproducibility and stability, with large buffer capacity, small dilution value and small temperature coefficient

(3) the preparation method of the solution is simple

2. How to prepare pH buffer solution

for general pH measurement, a complete set of pH buffer reagent (250ml can be prepared) can be used. When preparing the solution, deionized water should be used and boiled in advance for 15-30 minutes to remove dissolved carbon dioxide. Cut open the plastic bag, pour the reagent into the beaker, dissolve it with an appropriate amount of deionized water, wash the packaging bag, and then pour it into a 250ml volumetric flask, dilute it to the scale, and shake it well

3. How to properly store and use pH buffer solution

after the buffer solution is prepared, it should be packed in a glass bottle or polyethylene bottle (alkaline pH buffer such as ph9.18, ph10.01, ph12.46, etc., should be packed in a polyethylene bottle). The bottle cap should be tightly capped, and it should be stored in a refrigerator at a low temperature (5-10 ℃), which can be used for about two months generally. If turbidity, mildew or sedimentation are found, it cannot be used anymore. When using, prepare several 50ml polyethylene vials, pour the buffer solution in the vials into the vials, and place them at ambient temperature for 1-2 hours, and then use them after the temperature is balanced. Do not pour it back into the bottle after use to avoid pollution. The buffer solution in the small bottle can be used for 2-3 days under the environmental condition of 10 ℃. Generally, the use time of ph7.00, ph6.86 and ph4.00 solutions can be longer. The pH value of ph9.18 and ph10.01 solutions is relatively easy to change due to the absorption of CO2 in the air

4. What is the purpose of pH buffer solution

⑴ calibrate the pH meter before pH measurement

⑵ to verify the accuracy of the pH meter. For example, after calibrating the pH meter with ph6.86 and ph4.00, insert the pH electrode into the ph9.18 solution, and check whether the displayed value of the instrument is consistent with the PHS value of the standard solution

⑶ check whether the pH meter needs to be recalibrated during general accuracy measurement. After the pH meter is calibrated and used, it may drift or change. Therefore, before the test, insert the electrode into a standard buffer that is close to the tested solution and the stretching range can reach 20% of its own size. Determine whether it needs to be recalibrated according to the error