Metrohm 837 IC Degasser - Manual (Page 7)

1.1 Instrument description
837 IC (Eluent/Sample/Combi) Degasser/ Instructions for Use 8.837.1003
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1 Introduction
1.1 Instrument description
837 IC Eluent Degasser:
The 837 IC Eluent Degasser is used for degassing eluents. Gas bub-
bles in eluents produce an unstable baseline as high-pressure pumps
for ion chromatography can transport liquids but not gases. This is why
eluents must be degassed before use. The degasser module is simply
included between the eluent and the IC pump. Then the eluent flows
through the special Teflon-AF ® -capillary, which is located in a vacuum
chamber. The vacuum removes small gas bubbles, and reduces the
content of solved gases like carbon dioxide or nitrogen. Time-
consuming manual eluent degassing is no longer necessary. The 837
IC Eluent Degasser is equipped with two vacuum chambers so that two
eluent flows can be degassed simultaneously.
837 IC Sample Degasser:
The 837 IC Sample Degasser is also used for degassing samples. For
samples apply the same rules as for eluents: they cannot be injected
directly, if they either contain or release gas bubbles. The indication of
injecting samples containing gas bubbles is a poor reproducibility, be-
cause the amount of sample in the sample loop would vary. This means
that these (gas-containing) samples must be degassed before the in-
jection. The 837 IC Sample Degasser automates the degassing. Before
the sample reaches the injection valve it passes a special Teflon-AF ® -
capillary, which is located in a vacuum chamber. The vacuum removes
small gas bubbles, and reduces the content of solved gases like car-
bon dioxide or nitrogen. The 837 IC Sample Degasser is equipped with
a large-volume vacuum chamber and, for example, allows direct de-
termination of drinks containing carbon dioxide without any manual
sample preparation.
837 IC Combi Degasser:
The 837 IC Combi Degasser is the combination of an 837 IC Eluent
Degasser and an 837 IC Sample Degasser. Both degassing of eluents
and degassing of samples can be carried out with it. The 837 IC Combi
Degasser is simply included between eluent and IC pump or between
sample and the injection valve. Eluent and sample then flow through
the special Teflon-AF ® -capillaries, which are located in separate vacu-
um chambers. The 837 IC Combi Degasser is equipped with a total of
three vacuum chambers so that two eluent streams and one sample
stream can be degassed simultaneously.