PH Buffer Solution For Consistent and Accurate Calibration

At AML Instruments, we can provide you with technical and/or certified pH Buffer Solutions (hydrogen ion buffers), guaranteeing maximum precision with certification to  NIST/DIN to ensure compliance and traceability.

pH buffers stay at a constant pH value, making them ideal for calibrating pH meters and pH sensors. The three most common pH buffer solutions, normally distinguished by their colour, are pH 4 (red), pH 7 (green) and pH 10 (blue).

All our buffer solutions are manufactured by the World leader in pH measurement Mettler Toledo

Please click on the individual products for more information on individual products or get in contact with our team.

You can contact them directly at Tel: 01522 789 375, via our contact form or on our Live Chat in the bottom right-hand corner of this web page.

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Frequently Asked Questions

Below are several common questions asked by people looking for more information on Buffer Solutions.

How do you store a pH buffer solution?

There are several recommended ways to store a pH buffer, 

  • Never re-use buffer, and always decant a small amount into a clean and dry container to complete the calibration with, then dispose of the solution. You must never place the sensor into the storage container.
  • Keep the container sealed. 
  • The container should be made of a material resistant to acids and bases, such as glass or plastic. 
  • The cover should be tight-fitting to prevent evaporation and spillage if knocked over whilst in storage.
  • The storage unit should be a cool, dry place, with the solution discarded once it has reached its expiry date.

How do you dispose of the solution?

The majority flush the pH solution down the drain with lots of water. Some recommend neutralising the solution before disposing of it.

If you have large volumes of buffer solutions to dispose of, you will need to seek guidance from your Health and Safety department.

Are there any safety concerns associated with using a pH buffer solution?

pH buffer solutions are generally considered to be safe when used as directed. However, there are a few potential safety concerns to be aware of.

Following skin contact – Wash off with soap and plenty of water. If irritation persists, seek medical attention.

Eye Contact – In case of contact with the eyes, rinse immediately with plenty of water and seek medical services.

Ingestion – Do not induce vomiting. Rinse your mouth thoroughly. If the casualty has ingested large amounts or discomfort continues, wash the mouth thoroughly and obtain medical attention.

If inhaled – If breathed in, move the person into the fresh air. If not breathing, give artificial respiration. Consult a physician. 

How is a pH buffer solution made?

A pH buffer solution is an aqueous solution based on a mixture of a weak acid and its conjugate base or vice versa. The weak acid and conjugate base react with each other to form a buffer, which resists changes in pH.

What are the benefits of using a pH buffer solution?

A buffer solution’s major benefit is keeping a pH value nearly at a constant level and is used across multiple chemical applications. It is essential all pH meters and probes are calibrated at regular intervals, without this calibration your pH reading will be inaccurate. 

Here are a few examples:

Human blood – Human blood must stay between 7.35 and 7.45. Falling outside of this range will lead to either acidosis or alkalosis. A mixture of carbonic acid and bicarbonate is used to maintain the desired pH range.

Fermentation – Buffer solutions are also used in the production of alcohol and are added before the fermentation process to protect the product from becoming acidic. They are also used in bread making to stop the drop in the pH value by releasing carbon dioxide.

Calibration of a pH meter and sensor – To ensure the accuracy of your pH meter and its sensors, you need to calibrate them regularly. The electrodes must be calibrated daily if they are being used in a laboratory. Using the most common pH buffer solutions during calibration, you can monitor and adjust the pH meter to maintain its accuracy.