Recently, I am using Ag/AgCl as RE in a basic three-electrode system to scan CV in K3Fe(CN)6/ K4Fe(CN)6. I realized that the color of the solution in RE changed from transparent to yellow. Can this phenomenon affect my experiment? How can I restore its color?
Thanks for your help.
Your test solution penetrated to your ref. electrode. If you have possibilities to change the inner solution this is the best. Also a membrane or junction of your ref.electrode a contaminated. Wash it with distilled water. This phenomenon does not affect your experiment if a penetrated solution does not disturb ref. electrode potential. Frequently it is absent. But later your contaminated electrode can be a problem for other experiments that should be free from K3Fe(CN)6/ K4Fe(CN)6.
The Ag/AgCl ref. electrode is filled by a saturated KCl solution. But in some reason other salt solution possible use (if K+ ions should be excluded from an experiment). Also, other KCl concentration is possible. Potential of those electrodes are little other. In specification to your electrode, you can try to find information about the inner solution.
Wash your electrode and change the inner solution.
Dear Dmytro Snizhko ,
My Ag/AgCl ref.electrode is filled in 3M KCl solution and its design doesn't allow to replace the inner solution. Although I often clean the electrode by distilled water, the K3K4/0.1M KCl solution penetrated my ref.electrode. Maybe I need to prepare a new ref.electrode for irrelevant experiments. Thank you for your suggestion.
Dear @Tinh Phung
The happened case definitely affect on your experiments due to the change in electrode potential. It is difficult to remove the K4Fe(CN)6 from inner solution of your reference electrode. Only the solution of this problem is to remove inner solution and cleaning the Ag surface with the help of Ammonium hydroxide to remove AgCl coating. After cleaning, you need to anodize the Ag surface to reconstruct the AgCl coating. After anodization, fill the electrode with KCl solution of concentration as before and store it in KCl solution of same concentration. The said procedure may help you to recover your original performance.
Can you put here a photograph of your Ag/AgCl electrode?
Dear Suraj Anandrao Khalate
I'm using RE purchased from Basinc. Here is its picture.
Dear Suraj Anandrao Khalate
I'm using RE purchased from Basinc. Here is its picture.
It looks as it doesn't support disassemble.
You need a new electrode.
You can try to disassemble this, but a big chance to damage it. Are you ask recommendations from the firm (Basinc)?
You can still use in your experiment with knowledge about the contamination if its disturbance is not too big for your measurements. Check its potential relatively other ref. electrode.
Dear Tinh Phung
I agree with Dmytro Snizhko .
You need first to check the variation in potential using another standard reference electrode. you can use that reference for practice.
But due to contamination, you cannot use that reference for standard research.
You can consult with the supplier and the company who producing this product (BASi), contact at :
Service and Repairs [email protected] 765.463.4527, ext. 5809
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