Metrohm 850 Professional IC Cation - Prep 2 - Manual (Page 100)

5.1 Problems and their solutions
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850 Professional IC – Cation – Prep 2
Problem Cause Remedy
Poor reproducibility
of the retention
times Eluent – Leak in the eluent
path. Check the eluent path.
Eluent – Blockage in the
eluent path. Check the eluent path.
Chromatograms
have poor resolution Separation column –
diminished separating effi-
ciency. ￭ Regenerate separation column (see Chap-
ter 4.13.4, page 87).
￭ Replace separation column (see "Connect-
ing and rinsing the separation column",
page 60).
Conductivity detec-
tor is not recognized
in the software No connection.
￭ Check the cable connection (32- 1 ).
￭ Turn the instrument off and on again (after
15 seconds).
Extreme spread of
the peaks in the
chromatogram.
Splitting (dual
peaks) Connections – dead vol-
ume in the system. Check the connections (see Chapter 2.5, page
17) (use PEEK capillaries with an internal diam-
eter of 0.25 mm between the injection valve
and detector).
Guard column – diminished
performance. ￭ Replace guard column (see Chapter 2.19,
page 57).
Separation column – dead
volume at column head. ￭ Install separation column in reverse flow
direction (if permitted by the information
sheet).
￭ Replace separation column (see "Connect-
ing and rinsing the separation column",
page 60).
Precision problems -
significant scatter-
ing of the measured
values Sample – Gas bubbles in
the sample. Use sample degasser (see Chapter 2.13, page
43).
Injection valve – sample
loop. Check installation of the sample loop (see
Chapter 2.15.1, page 49).
Sample – Rinsing volume
too low. Prolong the rinsing time (see Chapter 4.8,
page 80).
Injection valve – defective. Request Metrohm Service.
Unexpected change
to the retention
times in the chroma-
tograms Separation column –
diminished separating effi-
ciency. ￭ Regenerate separation column (see Chap-
ter 4.13.4, page 87).