Metrohm 850 Professional IC Cation - Gradient - Manual (Page 84)

6.1 Problems and their solutions
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850 Professional IC Cation – HP-Gradient
Problem Cause Remedy
Guard column – diminished
performance. ￭ Replace guard column (see Chapter 3.17,
page 47).
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 49).
Precision problems -
significant scatter-
ing of the measured
values Sample – Gas bubbles in
the sample. Use sample degasser (see Chapter 3.13, page
39).
Injection valve – sample
loop. Check installation of the sample loop (see
Chapter 3.14.1, page 41).
Sample – Rinsing volume
too low. Prolong the rinsing time (see Chapter 5.8,
page 69).
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 5.11.4, page 72).
￭ Replace separation column (see "Connect-
ing and rinsing the separation column",
page 49).
Eluent – Gas bubbles in the
eluent. Check connections of the eluent degasser (see
Chapter 3.9, page 31).
High pressure pump –
defective. Request Metrohm Service.
Vacuum is not being
built Eluent Degasser – Connec-
tor Vacuum on the rear of
the instrument not (tightly)
sealed. ￭ Seal the connector Vacuum tightly with a
6.144.6040 threaded stopper.
or when using an 872 Extension Module:
￭ Connect an FEP tubing between the IC
instrument and the Extension Module and
tighten both clamping screws until they
seal.