pH Measurements: Avoiding the Most Common Mistakes

Performing a pH measurement necessitates proper and correct parameters in order to arrive at an optimal and validated result. As such, these are some of the best practices involved in accurately performing a pH measurement. Along the way, some of the most common mistakes practiced in a pH measurement are avoided and clarified for the entire application process.

Selecting the Correct Electrode

It is an established fact that choosing the best electrode for your application is quite daunting as there is a wide variety of options you need to choose from in the market. True enough, troubleshooting for your application already happens even before you place the pH sensor on your sample solution. As this is an integral part of your application, selecting the right electrode might as well be the end-all-be-all of your application. Essentially, you can search for the best electrodes needed for which application of your sample solution. As each electrode is fit for a different application, you might as well do further research on the market and consider if this is the right electrode for your sample solution.

Preparing for the Measurement

One of the vital steps you should do before your application is to prepare the needed tools for the whole entire process. And this preparation comes with checking some defects or cracks on your electrode. If you entirely skip this process, your application is at risk of being contaminated. As such, you need to open the plug and check the consistent flow of electrolyte inside the electrode. If there is a stable electrolyte level, you should also get stable results from your application.

More than this, to even ensure that there is an outflow caused by the hydrostatic pressure, make sure that the electrolyte is filled to the brim. Now, if the level of the sample is much higher than the level of the electrolyte, your results might be unstable and can no longer be reproduced. When inserting your sensor into the sample, make sure that you insert it deep enough so that the glass membrane and the diaphragm are both covered.

Performing the Calibration

Depending on the number of measurements and samples, performing the calibration should be done at least twice a week. It is even recommended to do this on a regular basis. Now, if your sample matrix is often used, there is a probability of contamination. As such, this necessitates a frequent and thorough calibration. Even if you have received a new sensor or one that is stored for a longer period of time, calibrating your sensor is just as important in making sure that contamination does not happen in your application.

Essentially, using fresh and new buffers is highly recommended in achieving optimal results in your calibration. Make sure that you choose the right buffer for our calibration. Most importantly, your sample should be within the calibration pH value. This is an integral part of the calibration process as this dictates the results you might get out of the application.

Correctly Storing the pH Electrode

If you want to increase the lifetime of your electrode, storing it in a correct and proper way is vital in ensuring its longevity. A general rule of thumb: never store your pH electrode dry! Now, why is this so? Essentially, if your store your electrode dry, you are lowering and eventually destroying the hydration layer of the electrode. In the long run, the sensor becomes slower and then, it will no longer be useful and applicable.

Properly Cleaning the pH Electrode

A durable pH sensor affects the whole process of the application. As such, cleaning an electrode is an integral part of the entire process. Here, the electrode must be rinsed with deionized water. Now, if the sample you used was sticky or it even contains proteins, it is highly suitable to use a different type of solvent in properly cleaning and removing the contamination in the electrode. To increase the lifetime of an electrode significantly, giving the electrode a special treatment will go a long way in ensuring its efficiency and longevity.

Another rule of thumb: never wipe the sensor with a tissue. Now, why is this so? Essentially, when you do this, you are charging the glass surface of the membrane. When you are now doing your measurement, the electrostatic energy present in the glass membrane will eventually affect the results of your measurement.

Correct and Consistent Stirring

It is highly recommended that consistently stirring the electrode at the same speed and direction even on a different type of electrode you are using is integral during the analysis of your application. Therefore, the stirring of the electrode should match all of the buffers and samples utilized in the whole application process. If you want to receive optimal and consistent results, a consistent stirring of the electrode entirely affects the results you aim for from the application process.

Checking pH Electrodes

One of the easiest ways to check for the pH electrodes is generally recommended to check for the slope and the pH value right after the calibration. To give you an idea of the correct measurement of the recommended slope, it should range between 95-103% while the pH value should range between 6.8-7.2. essentially, if you want to infer and deduce more information from the electrodes, implementing Metrohm’s instruments in the pH test is vital in knowing further information from the test application.