Metrohm 871 Advanced Bioscan - Manual (Page 34)

4 Notes - Maintenance - Faults
871 Advanced Bioscan / Instructions for Use 8.871.1003
26
4.3.3 Cleaning the working electrode
The surface of the gold working electrode should be cleaned whenever
you notice that its electrochemical properties have changed. This may
be caused by the deposition of reaction products. High current flows
can also alter the electrode surface; this is indicated by a very reduced
sensitivity after longer periods of use.
In principle, you should avoid too high analyte concentrations or dirty
samples. This measure as well as the regenerative effect of the pulse
technique normally supersedes the polishing of the electrode.
You should on
flow
ly polish the electrode surface with the polishing paste
supplied, if the sensitivity cannot be restored by intensive rinsing of the
cell with water and cleaning the electrode surface by rubbing it
with an eraser.
Use the diamond paste (6.2802.110) supplied to polish the surface of
the electrode together with the polishing disk (6.2802.100). Proceed as
follows:
1 Rinse the polishing disk
Rinse the polishing disk with high purity water before use.
2 Shake the diamond paste
Shake the bottle containing the diamond paste thoroughly be-
fore use.
3 Polish the electrode
Add a few drops of the paste to the wet polishing disk and pol-
inute with uniform move-
form
ish the electrode for approx. one m
ments in the of a figure 8. Exert only a slight pressure.
rode
C condition visually and repeat the polishing
ry.
4 Clean the elect
Clean the electrode with a paper tissue moistened with ethanol.
heck the surface
process if necessa
5 Rinse electrode and measuring cell
Rinse the electrode and the measuring cell with high purity wa-
ter.
6 Mount the measuring cell
Remount the measuring cell.
7 Clean the polishing disk
Clean the polishing disk with high purity water and store it dust-
free in a plastic cover.
4.3.4 Changin
If you wish to replace an IC separating column by a column of the same
type, proceed as follows (see Figure 3):
g separating columns
Identical separation system