Q&A

♦ Questions about reference electrode

Question: Is it possible to refill the internal solution for the RE-1B Reference electrode (Ag/AgCl)?

Answer: It will not be possible to refill the internal solution. Also, if the porous glass from the liquid junction get dry and the porous blocked, it will not be possible to regenerate them. Be careful not to dry the liquid junction.

Question: The reference electrode is almost new, however the internal solution is slightly decreased, why?

Answer: For the production procedure, it is almost impossible to avoid small air bubbles inside of the electrode. However, the small bubbles will not affect the measurement. Furthermore, when you keep the electrode without use, for a long time, the air bubble could increase.

Question: After an experiment, the porous glass from the liquid junction have discolored. Can I still use it?

Answer: Even if the porous glass was discolored, most of the times it does not affect the measurement. For the porous glass structure, there is not a way to avoid the discoloration. If the porous were not blocked, it can be used without problem. It can not be used when it is possible to observe the half potential of the voltammogram increase and the peak potential shift, compared with a previous result.
However, after long time use, the serious adsorption of substrates may possibly cause the liquid-junction (IPPG (Ion Permeability Porous Glass) tip) resistance becoming higher, and the potential drift occurs.
In the worst case, the extra-large resistance of the IPPG tip (very deep color) may finally cause the potentiostat oscillation, and the CV measurement can not be carried out. In this case, the change of the reference electrode is recommended.

Question : Can RE-7 Non Aqueous reference electrode (Ag/Ag+) be used in a methylene chloride solvent?

Answer: The internal solution is delivered separately, the user needs to fill the electrode yourself before it will be used. When the electrode is used in a methylene chloride solvent, it is recommended to fill the electrode with the same electrolyte, instead of the standard solution, TBAP acetonitrile.

Question: What is the reference potential for the RE-7 Non Aqueous reference electrode (Ag/Ag+)?

Answer: The potential for the organic solvent is unstable, it makes unable to have a fixed value for the potential.

♦ Questions about Ag/AgCl Ink

Question: What is the reason for the instability of the potential when Ag/AgCl ink is used?

Answer: Ag/AgCl will be considering as a stable electrode only with the presence of the Cl- on the supporting electrolyte solution. If there is not enough chloride ion, it becomes unstable, and AgCl melts out in the solution. For the measured sample, adjust the chloride ion concentration, with KCl or NaCl, to 3 M. If the addition of the KCl or NACl, directly to the sample is difficult, please use the sample holder.

Question: When the platinum or gold is used, is there a possibility that the Ag/AgCl ink peal out during the measurement?

Answer: If you did not dry enough, there is a possibility to have the ink peeled out during the measurement.
For the evaluation of the Ag/AgCl Ink, the potential was measured for 60 hours in 3 M NaCl solution. The potential showed stable, and the coating was not peeled out. The adhesion of the ink to the surface of the platinum and gold is relatively good, even a lightly rub, it was not peeled out.

Question: After coating and drying the Ag/AgCl, is it be soluble in acetone or ethanol?

Answer: Yes, it is soluble in acetone and ethanol.

Question: After coating and drying the Ag/AgCl, is there a damage when immersed in an acid or alkaline solution? And, how will be?

Answer: Ag/AgCl Ink is supplied for application as a reference electrode. In order to obtain a stable potential, it has been recommended to use the neutral supporting electrolyte, containing chloride ions. The potential becomes unstable to some extent when immersed in acid and alkali directly, the damage is proportional to the intensity of the acidic or alkaline. For the measurement using acid or alkaline solution, it is recommended to use a sample holder, to obtain a stable potential.

Question: When applying the Ag/AgCl Ink the surface is unevenness, it is not uniform, does it affect the function? Furthermore, if the thickness is not uniform as well?

Answer: After coating the metal surface, if there is some bare area, it will react and it will affect in the stability of the potential. It is recommended to apply the Ag/AgCl Ink in full area which will be in contact with the sample. If the full surface is coating by Ag/AgCl Ink and there is sufficient chloride ion concentration in the solution, the thickness of the ink will not affect the potential stability.

♦ Questions about QCM/EQCM Flow cell and Quartz crystal

Question: When the quartz crystal for EQCM is cleaning using the ultrasonic cleaner, what could happen with the electrode?

Answer: Using the ultrasonic cleaner over 5 minutes at high power, the electrode could peeled out. Also, do not rub the surface, it will scratch the electrode.

Question: How does the EQCM electrode surface can be polished?

Answer: It can not be physically polished. There is a possibility that when you clean with alumina, the residue of alumina penetrate and fix between the metal and substrate.

♦ Questions about ALS products

Question: Protein was attached to the surface of the gold electrode. Is there a way to remove it?

Answer: When the protein is attached to the gold electrode surface, it will be very difficult, and it will expend time to clean completely, because rough polishing will be necessary.
For the polishing of the gold electrode, use the 800 to 1000 grit emery paper, with a few drops of water, polishing for few minutes with lightly force in circular movement. If you apply force and scratch the surface, it will take time to have the mirror surface finish. After rough polishing, you need to polishing with diamond, and last, finish with alumina polishing.
In addition, do not wash with strong acid-strong base. PEEK resin will be degenerated, and the electrode will not be able to use.

Question: Would be possible to manufacture the electrode by supplying the metal?

Answer: Customized electrode is possible, even for a different size or shape of the electrode. We only do not accept the supply of the dangerous/hazardous material.
For customized product, be free to contact us or the sales partner in your country.

Question: What is the temperature range that the electrode can be used?

Answer: ALS products were manufactured to be applied in room temperature. We do not guarantee for use in high or low temperature.

Question: As a result of ultrasonic cleaning in an organic solvent, the electrode extremity cracked. Could it be exchanged?

Answer: As it has been described in the instructions manual attached to the product, damage by such cleaning method is not covered under warranty. It can not be exchanged.

Question: In the instruction manual for PK-3 Electrode polishing kit, what is the criteria for "mirror surface"? Also, when does the diamond polishing pad need to be changed?

Answer: "Mirror surface" is when the surface show uniform. In other words, when there is not a evidence of the lines on the surface. After visual check, if the CV obtained using the standard sample, ferrocene or potassium ferricyanide, determined a clear reversible waveform, the surface of the electrode is considered acceptable.
It will be possible to use the diamond pad, while the dirt can be removed with a water rinse.

Question: Is it possible to polish the IDA electrode?

Answer: It can not be polished physically. IDA electrode is very sensitive, please take care to do not touch the IDA electrode.
Furthermore, IDA electrode is considered as a disposable electrode.

Question: In the CV measurement using sample holder, the current does not flow. Why?

Answer: Check if the porous glass at the liquid junction is sufficiently wet or if there is some bubble near the liquid junction. Before use the sample holder, keep the liquid junction immersed in a electrolytic solution and verify if there some bubble which can block the flow of the current.

Question: There are some patterns on the surface of the GCE Glassy carbon electrode, is there any problem to use this electrode?

Answer: From the features of the Glassy carbon, the patterns on the surface will be always present. These patterns will not affect the characteristics of the material.

Question: Could ITO electrode be used in a spectroelectrochemical measurement? What is the specification?

Answer: ITO is deposited in a quartz glass substrate, and it transmits the light of the visible range, but do not transmit the light of ultraviolet range.
It is resistant for an organic solvent, and weak for a strong acid and alkaline solution. Also, it will melt easily in hydroiodic acid.