Metrohm 871 Advanced Bioscan - Manual (Page 36)

4 Notes - Maintenance - Faults
871 Advanced Bioscan / Instructions for Use 8.871.1003
28
4.4 Faults and malfunctions
tions and their rectification
If difficulties arise with the IC system during analyses, their causes are
best investigated in the order separating column
4.4.1 Malfunc
→ pump → eluent
→ 871 Advanced Bioscan. Several of the malfunctions which may
appear are listed in the following table with details of possible causes
and countermeasures.
Malfunction Cause Rectification
Baseline with high
noise level, pulsa-
tion • Contaminated pump
values • Clean the valves (see sec-
tion 4.2.2)
• Faulty piston seals
selected sensitivity
• Air bubble in flow cell
n-
• Flow cell leakage
minated
• Replace the piston seals
or lower the sensitivity
• Remove air bubble, degas
eluent continuously
ced
Bioscan oven
• Clean working electrode
• Check capillary connec-
tions at flow cell
• Replace eluent
• Quality of the pump
does not suffice for the
(see section 4.2.2)
• Use pulsation dampener,
use more powerful pump
• Temperature fluctuation • Switch on 871 Advan
• Working electrode co
taminated
(see Chapter 4.3.3)
• Eluent conta
Drift o
baseli
too much
d
make leakproof
• Replace eluent
f the
ne
• Thermal equilibrium not
yet reached
• Leak in system
• Condition system with
heating switched on
• Check connections an
• Old Eluent (
CO2)
Decre
tivity
(S/N lower)
ed, e.g. by con-
taminated sample
• Eluent contaminated
(high background
signal)
(see Chapter 4.3.3), dilute
sample
mize measuring po-
• Replace eluent
• Check and adjust pH
asing sensi- • Working electrode con-
taminat • Clean working electrode
• Wrong measuring poten- • Opti
tial tential
• Eluent pH changed
High background • Eluent contaminated
poten-
ad peaks due to
compounds
• Separation column is
• Replace eluent
• Optimize parameter
• Await complete elution of
these compounds
• Replace column
signal
• Wrong measuring
tial / pulse settings
• Very bro
retarded
bleeding