Metrohm 2.946.0010, Руководство пользователя

Страница: 65 / 81

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
7 Troubleshooting
￭￭￭￭￭￭￭￭
57
Problem Cause Remedy
The method parameters
are not suitable for the
application problem. Identify the problem and adapt the voltam-
metric parameters and/or the electrolyte com-
position.
The stirrer does not work
correctly. See Stirrer - the stirrer does not rotate.
Peak position - the
peak in the sample
as well as for the
standard addition
has shifted. Concentration of chloride
in the measuring solution
has changed. The potential of the reference electrode
depends on the concentration of chloride in
the measuring solution. If the sample already
contains significant amounts of chloride,
reduce the concentration of chloride in the
electrolyte accordingly. If that is not possible or
does not improve the situation, adapt the peak
recognition according to the new peak posi-
tion
(see "Adapting the peak recognition",
page 29) . In this case also the potentials for
cyclovoltammetric and potentiostatic pretreat-
ment may need to be adapted.
The electrode was stored in
water. Solid state electrodes should not be stored in
ultrapure water, since this can affect the condi-
tion and sensitivity of the electrode. For rec-
ommended storage conditions refer to the
respective application documentation.
The electrode is too old. Replace the electrode with a new one.
Peak position - the
peak in the sample
has shifted, but the
standard addition is
ok. The evaluated peak in the
sample is not the analyte. Adapt the peak recognition (see "Adapting the
peak recognition", page 29) in order to evalu-
ate the correct peak.
Normal behavior if com-
plex formation is involved. In some specific applications, in which com-
plex formation of the analyte is involved, this is
a normal behavior.
Peak shape - double
or multiple peaks Another substance shows
a peak close to the ana-
lyte.
￭
Identify the interference and remove it
from the measuring solution.
￭
If possible, adapt the electrolyte to get a
better separation between the two peaks.
￭
If possible, adapt the method parameters
to minimize the interference by the addi-
tional peak.