Metrohm 850 Professional IC Anion MCS Gradient - Manual (Page 112)

5.1 Problems and their solutions
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
102 ￭￭￭￭￭￭￭￭
850 Professional IC –Anion – MCS – Gradient
Problem Cause Remedy
￭ Replace separation column (see "Connect-
ing and rinsing the separation column",
page 64).
Conductivity detec-
tor is not recognized
in the software No connection.
￭ Check the cable connection (34- 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
13) (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 2.21,
page 61).
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 64).
Greater rise in the
baseline MSM – reduced capacity. Regenerate the MSM (see Chapter 4.11.3.1,
page 87).
Precision problems -
significant scatter-
ing of the measured
values Sample – Gas bubbles in
the sample. Use sample degasser (see Chapter 2.13, page
39).
Injection valve – sample
loop. Check installation of the sample loop (see
Chapter 2.14.1, page 40).
Sample – Rinsing volume
too low. Prolong the rinsing time (see Chapter 4.8,
page 84).
Injection valve – defective. Request Metrohm Service.
MCS – vacuum too low. ￭ Check connectors. If they are ok:
￭ Contact the Metrohm Service.
Unexpected change
to the retention
times in the chroma-
tograms Separation column –
diminished separating effi-
ciency. ￭ Regenerate separation column (see Chap-
ter 4.15.4, page 97).
￭ Replace separation column (see "Connect-
ing and rinsing the separation column",
page 64).