Non Aqueous reference electrodes
∗RE-7VT Non Aqueous reference electrode screw type (Ag/Ag+) was designed to be used in ALS brand flow cell (Cross, Radial, EQCM, SEC-2F), for this reason there is a possibility that it will not be compatible in another brand flow cell.
- For apply in an organic solvent sample
- Internal solution changeable
Preservation of the electrode
- Fill the sample holder with an acetonitrile/0.1 M tetrabutylammonium perchlorate/0.01 M AgNO3 solution.
- Rinse the Ag wire with acetone.
- Keep the electrode immersed in an acetonitrile/0.1 M tetrabutylammonium perchlorate solution, with or without Ag ion (0.01 M AgNO3).
- Avoid the dry of the Vycor® glass, it could cause the crash of the Vycor® glass tip, caused by the salt crystallization inside of the glass. Make sure to keep the tip always wet.
- Before assembly the electrode, immerse and keep the Vycor® glass tip in an organic solvent for at least one hour.
- If bubbles are present around the Vycor® glass, remove with a slight tapping. Air bubbles will isolate, blocking the current flow.
- Use only high grade products and reagents.
- Wash with acetonitrile. Salt crystallization, in the inner side of the Teflon cap and at the edge of the sample holder, makes difficult the assembly.
This electrode is silver-silver ion reference electrode for non-aqueous solution.
In order to reduce the liquid junction potential, use the same solvent and supporting electrolyte, as a sample and electrode internal solution.
The solvent in non-aqueous electrochemical should be considered as following:
- Electrode activity material and produced substance solubility.
- Select according to the potential area to be measured.
For example, dimethyl sulfoxide (DMSO) is major solvent in the negative potential area, and acetonitrile (ACN) is major solvent in the positive potential area.
The non-aqueous solution could contains impurities, and the impurities could cause the block reactions. Distilled the solvent sufficiently, to eliminated impurities before using.
If the sample is dissolved in an organic solvent, the supporting electrolyte must be added.
In order to select the supporting electrolyte, it is necessary to consider the following:
- Solubility in organic solvents
- Wide potential window
- No reaction with organic solvent
Typical supporting electrolyte:
- TEAP: Tetraethylammonium perchlorate
- TBAPF6: Tetrabutylammonium hexafluorophosphate
- Contents for, RE-7 Non Aqueous reference electrode （Ag/Ag+））
- RE-7 Teflon cap with Ag wire (1 pc)
- Sample holder dia 6mm (1 pc)
- RE-7 Electrolyte solution (3 mL)
- Immerse the sample holder tip (IIPG) in an organic solvent to be used,at least for one hour.
- Fill the sample holder with 0.6 mL of the electrolyte solution, use the pipette and fill it carefully.
- If there is a presence of the air bubble on the extremity (liquid junction), flick the sample holder with the fingers.
- Set the Teflon cap and seal the cap with a parafilm, to avoid the evaporation of the inner solution.
（※If the reagents will be prepared by yourself, choose a special grade reagents.）
Attention for the re-assembly
- There is a possibility to have the precipitation of the support salt inside of the sample holder and Teflon cap, please wash with acetonitrile before re-use.
- If the extremity tip (liquid junction IPPG) is dried, suport salt deposition will happen, blocking the holes which increases the liquid junction resistance or breaks the tip (IPPG). Keep it moistening in a solvent.
（∗Ion Permeability Porous Glass clogging can not be recovered.）
|012171||RE-7 Non Aqueous reference electrode (Ag/Ag+)||IPPG||ACN/TBAP||Glass||SVC-2, SVC-3, VC-4, Bulk electrolysis, RRDE, QCM|
|013394||RE-7S Non Aqueous reference electrode (Ag/Ag+)||IPPG||ACN/TBAP||Glass||SECM|
|013489||RE-7VT Non Aqueous reference electrode screw type (Ag/Ag+)||Ceramics||ACN/TBAP||Polymethyl pentene||Flow cell (Cross, Radial, EQCM, SEC-2F)|
IPPG: Ion Permeability Porous Glass