Correct storage of your pH probes can substantially increase the longevity of the probe saving you time, effort, and money. Here are a few points on how to get the most out of your probes.
Firstly, you should make sure you always keep your pH electrode moist, the best solution to submerge the probe for long and short term storage is 4M Potassium Chloride Solution (KCl). When Potassium Chloride Solution is not available, revert to pH 4 or 7 buffer solution. Potassium Chloride Solution (also known as pH Storage Solution or Electrode Storage Solution) is available from most laboratory suppliers including Westlab (Click here to view product).
It is also important that you do not store the pH electrodes in distilled or deionised water as this has little to no ions present and will cause the ions to leach out of the glass bulb and will render your electrode useless.
After storage, you may notice white Potassium Chloride crystals forming outside your electrode. This is normal and will not interfere with measurements. If this has occurred, gently wash the electrode with tap water and blot dry before use being careful not to put pressure on the electrode
https://www.westlab.com/blog/2017/11/29/what-is-the-correct-way-to-store-a-ph-electrode
pH Electrode Care
Electrode Calibration
Since glass pH electrodes measure H concentration relative to their reference half-cells, they must be calibrated periodically to ensure accurate, repeatable measurements. Our wide selection of commercial pH calibration buffers include solutions standardized against NIST-certified pH references for calibrating meters with resolution up to 0.001 pH.
Although calibration against one pH reference buffer (one-point calibration) typically ensures accurate pH measurement, frequent two-point or even three-point calibrations ensure the most reliable results. Make sure your pH system includes calibration buffers for a range of pH values.
Conditioning
pH electrodes are shipped with the electrodes moist. Prior to using your electrode for the first time, follow these three steps to condition your electrode:
- Remove the protective cap or rubber boot from the bottom of the sensor and rinse the electrode with distilled or deionized water.
- Place the electrode in a beaker containing one of the liquids listed below (in order of ionic ability to condition the electrode). Soak for 20 minutes.
- 3.8 M or 4.0 M KCL
- 4.0 pH buffer
- 7.0 pH bufferNote: Never condition a pH electrode in distilled or deionized waterÑlong term exposure to pure water will damage the special glass membrane.
- After conditioning the sensor for 20 minutes, rinse the electrode with distilled or deionized water. The electrode is now ready for calibration and to measure pH.
Handling
Electrodes should be rinsed between samples with distilled or deionized water. Never wipe an electrodewiping can cause erroneous readings due to static charges. Blot the end of the electrode with lint-free paper to remove excess water.
Refillable Electrodes
The filling solution in refillable electrodes should be filled up to, but not past, the refill hole. Make sure the refill hole is left open when measuring to ensure that the fill solution flows properly through the reference junction.
Storage
Always keep your pH electrode moist. We recommend that you store your electrode in a solution of 4 M KCl. If 4 M KCl is not available, use a pH 4 or 7 buffer solution. DO NOT store electrode in distilled or deionized waterthis will cause ions to leach out of the glass bulb and render your electrode useless.
After storage, you may notice white KCl crystals forming outside your electrode. This will not interfere with measurements. Simply rinse the electrode and blot dry before use.
https://www.coleparmer.com/tech-article/ph-electrode-care
