Electrode Care Procedures
Standard Cleaning
Cleaning the electrode periodically will help to recover lost sensitivity. If the same amount of fresh standard results in a significantly smaller peak than it did in earlier analyses, standard cleaning is recommended. Usually, the electrode will need to be cleaned every one to two months, but more frequent cleaning may be necessary depending on the quality of reagents used and the type of samples.
1. Please confirm visually that there are no particles on the surface. If there are, please blow them away to prevent scratching the electrode surface during the following steps.
2. Wet a lint-free wipe such as a Kimwipe with 100% acetone .
3. Make one or two linear strokes across the surface with moderate pressure to clean the electrode.
Diamond Paste Polishing for Platinum (WE-PT) or Glassy Carbon (WE-GC) Electrode
When using a WE-PT or WE-GC electrode, you may notice a low background current or that the standard cleaning procedure is no longer effective. In this case, you may need to expose new surface by polishing according to the following procedure.
1. Apply one small speck (about 1μL) of diamond paste (DC-10, 100.170.00) to the surface of the electrode.
2. Use a clean finger to rub the paste over the surface for one minute.
3. Rinse the surface with acetone to remove the paste.
4. Use a lint-free wipe wetted with acetone to clean off the remaining residue.
Electrodes
Graphite composite (WE-3G, 110.010.00)
The WE-3G electrode will not tolerate high organic concentration. The electrode will dissolve and lose sensitivity. You may see a pitted whitish surface. To avoid this, limit the concentration of organic in the mobile phase, < 30% for methanol, or <5% for acetonitrile. Other solvents have not been tested, but generally the stronger the organic solvent or the higher the concentration of the solvent, the short the lifetime of the electrode will be.
Glassy carbon (WE-CG, 110.110.00)
The WE-CG is slower to stabilize than WE-3G, especially when new or immediately after polishing. It will take 16 hours under applied potential and mobile phase flow for the electrode to fully stabilize. The baseline may be stable enough to perform some analyses after less than 16 hours. After the initial use, the electrode will stabilize in a few hours. Use standard clean procedure when decrease sensitivity is
evident. When adequate sensitivity cannot be recovered by standard cleaning, the electrode should be
replaced or polished with diamond paste (DC-10, 100.170.00).
Pure graphite (WE-PG, 100.040.00)
The WE-PG electrode is used in situation where high voltage must be applied because the signal will
demonstrate less noise. Use standard cleaning procedure when decrease sensitivity is evident.
Platinum (WE-PT, 100.030.00)
A new WE-PT will take 16 hours under applied potential and mobile phase flow for the electrode to fully
stabilize. Subsequent use will not require as long. With continued use, deposits may build up on the
surface of the electrode and reduce the sensitivity. If it happens, the back ground current will drop
extremely low (<2.0nA). Diamond paste (DC-10, 100.170.00) can be used to polish the surface as
needed. After polishing, a longer than normal time will be required for the electrode to stabilize.
Dual graphite composite (WED-3G, 110.100.00)
This is a dual electrode version of the WE-3G electrode to be used in ECD-700. Only one amperometric
cell per ECD-700 can have this electrode installed. A contact plate (WCL-7, 110.130.00) and push plate
(WCP-7, 110.120.00) need to be installed for the dual electrode to work properly.
This electrode performs similarly to WE-3G. Clean according to standard cleaning method when loss of
sensitivity is detected. However, do not fully submerge or sonicate the electrode in acetone, or the
integrity of the electrode may be compromised.
Dual glassy carbon (WED-GC, 110.110.00)
This is a dual electrode version of the WE-GC electrode to be used in ECD-700. Only one amperometric
cell per ECD-700 can have this electrode installed. A contact plate (WCL-7, 110.130.00) and push plate
(WCP-7, 110.120.00) need to be installed for the dual electrode to work properly.
This electrode performs similarly to WE-GC. Clean according to standard cleaning method when loss of
sensitivity is detected. However, do not fully submerge or sonicate the electrode in acetone, or the
integrity of the electrode may be compromised.
Gaskets
25 micron gasket (GS-25, 100.080.00)
50 micron gasket (GS-50, 100.090.00)
25 micron gasket for platinum electrode (GS-25P, 100.085.00)
50 micron gasket for platinum electrode (GS-50P, 100.100.00)